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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Zackay%2C+B&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Zackay%2C+B&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Zackay%2C+B&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.17939">arXiv:2501.17939</a> <span> [<a href="https://arxiv.org/pdf/2501.17939">pdf</a>, <a href="https://arxiv.org/format/2501.17939">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Significant increase in sensitive volume of a gravitational wave search upon including higher harmonics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+A+K">Ajit Kumar Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Anantpurkar%2C+I">Isha Anantpurkar</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a>, <a href="/search/astro-ph?searchtype=author&query=Islam%2C+T">Tousif Islam</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2501.17939v2-abstract-short" style="display: inline;"> Most gravitational wave searches to date have included only the quadrupole mode in their search templates. Here, we demonstrate that incorporating higher harmonics improves the search sensitive volume for detecting binary black hole mergers, challenging the conclusion of previous studies. Using the $\tt{IAS-HM}$ detection pipeline, and the simulated (injection) signals from the LIGO-Virgo-Kagra (L… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.17939v2-abstract-full').style.display = 'inline'; document.getElementById('2501.17939v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.17939v2-abstract-full" style="display: none;"> Most gravitational wave searches to date have included only the quadrupole mode in their search templates. Here, we demonstrate that incorporating higher harmonics improves the search sensitive volume for detecting binary black hole mergers, challenging the conclusion of previous studies. Using the $\tt{IAS-HM}$ detection pipeline, and the simulated (injection) signals from the LIGO-Virgo-Kagra (LVK) collaboration, we quantify the improvement in sensitivity due to the inclusion of higher harmonics. This improvement is significant for systems with higher mass ratios and larger total masses, with gains in sensitivity even exceeding $100\%$ at certain high masses. We also show that, due to using a marginalized detection statistic, the $\tt{IAS-HM}$ pipeline performs roughly as well as its quadrupole-mode-only counterpart even for equal mass-ratio mergers, and its sensitive volume is either better than or comparable to that of the individual LVK pipelines. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.17939v2-abstract-full').style.display = 'none'; document.getElementById('2501.17939v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.03019">arXiv:2501.03019</a> <span> [<a href="https://arxiv.org/pdf/2501.03019">pdf</a>, <a href="https://arxiv.org/format/2501.03019">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> An Independent Search for Small Long-period Planets in Kepler Data I: Detection Pipeline </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ivashtenko%2C+O">Oryna Ivashtenko</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2501.03019v1-abstract-short" style="display: inline;"> The unprecedented photometric precision of Kepler mission allows searching for Earth-like planets. However, the current Kepler catalog exhibits insufficient reliability for long-period low signal-to-noise planets due to systematic false alarms caused by correlated and non-Gaussian noise. As a result, it remains hard to measure the occurrence rate of such planets. We aim to obtain a more reliable… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.03019v1-abstract-full').style.display = 'inline'; document.getElementById('2501.03019v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.03019v1-abstract-full" style="display: none;"> The unprecedented photometric precision of Kepler mission allows searching for Earth-like planets. However, the current Kepler catalog exhibits insufficient reliability for long-period low signal-to-noise planets due to systematic false alarms caused by correlated and non-Gaussian noise. As a result, it remains hard to measure the occurrence rate of such planets. We aim to obtain a more reliable catalog of small (Kepler MES$\lesssim$12) long-period (50-500 days) planet candidates from Kepler data and use it to improve the occurrence rate estimate. This work develops an independent search pipeline that takes into account noise non-Gaussianity and physical prior. It provides a tail-less background distribution with a rate of $\sim$1 false alarm per search for MES$\sim$7.8. We demonstrate the increase in detection efficiency for MES of 7.5-9 and $>$4 transits due to the background distribution control. We conducted a search on the entirety of Kepler data, applying permutation and injection procedures to calculate the probability of planetary origin for every candidate. The pipeline detected $\sim50$ candidate events with a high probability of originating from real planets, which will be presented in our future work. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.03019v1-abstract-full').style.display = 'none'; document.getElementById('2501.03019v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.17400">arXiv:2405.17400</a> <span> [<a href="https://arxiv.org/pdf/2405.17400">pdf</a>, <a href="https://arxiv.org/format/2405.17400">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.110.044063">10.1103/PhysRevD.110.044063 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New search pipeline for gravitational waves with higher-order modes using mode-by-mode filtering </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+A+K">Ajit Kumar Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.17400v2-abstract-short" style="display: inline;"> Nearly all template-based gravitational wave (GW) searches only include the quasi-circular quadrupolar modes of the signals in their templates. Including additional degrees of freedom in the GW templates corresponding to higher-order harmonics, orbital precession, or eccentricity is challenging because: ($i$) the size of template banks and the matched-filtering cost increases significantly with th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.17400v2-abstract-full').style.display = 'inline'; document.getElementById('2405.17400v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.17400v2-abstract-full" style="display: none;"> Nearly all template-based gravitational wave (GW) searches only include the quasi-circular quadrupolar modes of the signals in their templates. Including additional degrees of freedom in the GW templates corresponding to higher-order harmonics, orbital precession, or eccentricity is challenging because: ($i$) the size of template banks and the matched-filtering cost increases significantly with the number of degrees of freedom, $(ii)$ if these additional degrees are not included properly, the search can lose sensitivity overall (due to an increase in the rate of background triggers). Here, we focus on including aligned-spin higher harmonics in GW search templates. We use a new mode-by-mode filtering approach, where we separately filter GW strain data with three harmonics [namely $(\ell, |m|)=(2,2)$, $(3,3)$ and $(4,4)$]. This results in an increase in the matched-filtering cost by only a factor of $3$ compared to that of a $(2,2)$-only search. We develop computationally cheap trigger-ranking statistics to optimally combine the different signal-to-noise ratios (SNR) timeseries from different harmonics, which ensure only physically-allowed combinations of the different harmonics are triggered on. We use an empirical template-dependent background model in our ranking statistic to account for non-Gaussian transients. In addition, we develop a tool called band eraser which specifically excises narrow time-varying noisy bands in time-frequency space (without having to excise entire time chunks in the data). New GW candidate events that we detect using our $\texttt{IAS-HM}$ search pipeline and the details of our template banks are discussed in accompanying papers: Wadekar et al. [1] and [2] respectively. Apart from higher harmonics, we expect our methodology to also be useful for cheap and optimal searches including orbital precession and eccentricity in GW waveforms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.17400v2-abstract-full').style.display = 'none'; document.getElementById('2405.17400v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11+4 pages, 5 figures. Version appearing in PRD. The IAS-HM pipeline is available at https://github.com/JayWadekar/gwIAS-HM</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 110, 044063 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.02435">arXiv:2404.02435</a> <span> [<a href="https://arxiv.org/pdf/2404.02435">pdf</a>, <a href="https://arxiv.org/format/2404.02435">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.110.044010">10.1103/PhysRevD.110.044010 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fast marginalization algorithm for optimizing gravitational wave detection, parameter estimation and sky localization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.02435v2-abstract-short" style="display: inline;"> We introduce an algorithm to marginalize the likelihood for a gravitational wave signal from a quasi-circular binary merger over its extrinsic parameters, accounting for the effects of higher harmonics and spin-induced precession. The algorithm takes as input the matched-filtering time series of individual waveform harmonics against the data in all operational detectors, and the covariances of the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02435v2-abstract-full').style.display = 'inline'; document.getElementById('2404.02435v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.02435v2-abstract-full" style="display: none;"> We introduce an algorithm to marginalize the likelihood for a gravitational wave signal from a quasi-circular binary merger over its extrinsic parameters, accounting for the effects of higher harmonics and spin-induced precession. The algorithm takes as input the matched-filtering time series of individual waveform harmonics against the data in all operational detectors, and the covariances of the harmonics. The outputs are the Gaussian likelihood marginalized over extrinsic parameters describing the merger time, location and orientation, along with samples from the conditional posterior of these parameters. Our algorithm exploits the waveform's known analytical dependence on extrinsic parameters to efficiently marginalize over them using a single waveform evaluation. Our current implementation achieves a 10% precision on the marginalized likelihood within $\approx 50$ ms on a single CPU core and is publicly available through the package `cogwheel`. We discuss applications of this tool for gravitational wave searches involving higher modes or precession, efficient and robust parameter estimation, and generation of sky localization maps in low latency for electromagnetic followup of gravitational-wave alerts. The inclusion of higher modes can improve the distance measurement, providing an advantage over existing low-latency localization methods. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02435v2-abstract-full').style.display = 'none'; document.getElementById('2404.02435v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 7 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 110, 044010 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.09771">arXiv:2403.09771</a> <span> [<a href="https://arxiv.org/pdf/2403.09771">pdf</a>, <a href="https://arxiv.org/ps/2403.09771">ps</a>, <a href="https://arxiv.org/format/2403.09771">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> TRANSLIENT: Detecting Transients Resulting from Point Source Motion or Astrometric Errors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Springer%2C+O">O. Springer</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">E. O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">B. Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Konno%2C+R">R. Konno</a>, <a href="/search/astro-ph?searchtype=author&query=Sharon%2C+A">A. Sharon</a>, <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">G. Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Rubin%2C+A">A. Rubin</a>, <a href="/search/astro-ph?searchtype=author&query=Haddad%2C+A">A. Haddad</a>, <a href="/search/astro-ph?searchtype=author&query=Friedman%2C+J">J. Friedman</a>, <a href="/search/astro-ph?searchtype=author&query=Lubomirsky%2C+L+S">L. Schein Lubomirsky</a>, <a href="/search/astro-ph?searchtype=author&query=Aizenberg%2C+I">I. Aizenberg</a>, <a href="/search/astro-ph?searchtype=author&query=Krassilchtchikov%2C+A">A. Krassilchtchikov</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">A. Gal-Yam</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.09771v1-abstract-short" style="display: inline;"> Detection of moving sources over complicated background is important for several reasons. First is measuring the astrophysical motion of the source. Second is that such motion resulting from atmospheric scintillation, color refraction, or astrophysical reasons is a major source of false alarms for image subtraction methods. We extend the Zackay, Ofek, and Gal-Yam image subtraction formalism to dea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.09771v1-abstract-full').style.display = 'inline'; document.getElementById('2403.09771v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.09771v1-abstract-full" style="display: none;"> Detection of moving sources over complicated background is important for several reasons. First is measuring the astrophysical motion of the source. Second is that such motion resulting from atmospheric scintillation, color refraction, or astrophysical reasons is a major source of false alarms for image subtraction methods. We extend the Zackay, Ofek, and Gal-Yam image subtraction formalism to deal with moving sources. The new method, named translient (translational transient) detector, applies hypothesis testing between the hypothesis that the source is stationary and that the source is moving. It can be used to detect source motion or to distinguish between stellar variability and motion. For moving source detection, we show the superiority of translient over the proper image subtraction, using the improvement in the receiver-operating characteristic curve. We show that in the small translation limit, Translient is an optimal detector of point source motion in any direction. Furthermore, it is numerically stable, fast to calculate, and presented in a closed form. Efficient transient detection requires both the proper image subtraction statistics and the translient statistics: when the translient statistic is higher, then the subtraction artifact is likely due to motion. We test our algorithm both on simulated data and on real images obtained by the Large Array Survey Telescope (LAST). We demonstrate the ability of translient to distinguish between motion and variability, which has the potential to reduce the number of false alarms in transients detection. We provide the translient implementation in Python and MATLAB. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.09771v1-abstract-full').style.display = 'none'; document.getElementById('2403.09771v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 11 figures, submitted to AJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.07228">arXiv:2402.07228</a> <span> [<a href="https://arxiv.org/pdf/2402.07228">pdf</a>, <a href="https://arxiv.org/format/2402.07228">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Recovering pulsar periodicity from time of arrival data by finding the shortest vector in a lattice </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gazith%2C+D">Dotan Gazith</a>, <a href="/search/astro-ph?searchtype=author&query=Pearlman%2C+A+B">Aaron B. Pearlman</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.07228v2-abstract-short" style="display: inline;"> The strict periodicity of pulsars is the primary source of information we have to learn about their nature and environment, it allows us to challenge general relativity and measure gravitational waves. Identifying such a periodicity from a discrete set of arrival times is a difficult algorithmic problem, particularly when the pulsar is in a binary system. This challenge is especially acute in $纬$-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07228v2-abstract-full').style.display = 'inline'; document.getElementById('2402.07228v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.07228v2-abstract-full" style="display: none;"> The strict periodicity of pulsars is the primary source of information we have to learn about their nature and environment, it allows us to challenge general relativity and measure gravitational waves. Identifying such a periodicity from a discrete set of arrival times is a difficult algorithmic problem, particularly when the pulsar is in a binary system. This challenge is especially acute in $纬$-ray pulsar astronomy as there are hundreds of unassociated Fermi-LAT sources awaiting a timing solution that will reveal their nature, and may allow adding them to pulsar timing arrays. The same issue arises when attempting to recover a strict periodicity for repeating fast radio bursts (FRBs). Such a detection would be a major breakthrough, providing us with the FRB source's age, magnetic field, and binary orbit. The problem of recovering a timing solution from sparse time-of-arrival (TOA) data is currently unsolvable for pulsars in binary systems and incredibly hard even for single pulsars. In a series of papers, we will develop an algorithmic set of tools that will allow us to solve the timing recovery problem under different regimes. In this paper, we frame the timing recovery problem as the problem of finding a short vector in a lattice and obtain the solution using off-the-shelf lattice reduction and sieving techniques. As a proof of concept, we solve PSR J0318+0253, a millisecond $纬$-ray pulsar discovered by FAST in a $纬$-ray directed search, in a few CPU-minutes. We discuss the assumptions of the standard lattice techniques and quantify their performance and limitations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07228v2-abstract-full').style.display = 'none'; document.getElementById('2402.07228v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.06631">arXiv:2312.06631</a> <span> [<a href="https://arxiv.org/pdf/2312.06631">pdf</a>, <a href="https://arxiv.org/format/2312.06631">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> New black hole mergers in the LIGO-Virgo O3 data from a gravitational wave search including higher-order harmonics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+A+K">Ajit Kumar Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2312.06631v1-abstract-short" style="display: inline;"> Nearly all of the previous gravitational wave (GW) searches in the LIGO-Virgo data included GW waveforms with only the dominant quadrupole mode, i.e., omitting higher-order harmonics which are predicted by general relativity. Based on the techniques developed in Wadekar et al. [1,2], we improve the IAS pipeline by ($i$) introducing higher harmonics in the GW templates, ($ii$) downweighting noise t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.06631v1-abstract-full').style.display = 'inline'; document.getElementById('2312.06631v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.06631v1-abstract-full" style="display: none;"> Nearly all of the previous gravitational wave (GW) searches in the LIGO-Virgo data included GW waveforms with only the dominant quadrupole mode, i.e., omitting higher-order harmonics which are predicted by general relativity. Based on the techniques developed in Wadekar et al. [1,2], we improve the IAS pipeline by ($i$) introducing higher harmonics in the GW templates, ($ii$) downweighting noise transients ('glitches') to improve the search sensitivity to high-mass and high-redshift binary black hole (BBH) mergers. We find 14 new BBH mergers with $0.53\leq p_{\rm astro}\leq 0.88$ on running our pipeline over the public LIGO-Virgo data from the O3 run (we use the detection threshold as $p_{\rm astro}>0.5$ following the approach of other pipelines). We also broadly recover the high-significance events from earlier catalogs, except some which were either vetoed or fell below our SNR threshold for trigger collection. A few notable properties of our new candidate events are as follows. At $>95$\% credibility, 4 candidates have total masses in the IMBH range (i.e., above 100 $M_\odot$), and 9 candidates have $z>0.5$. 9 candidates have median mass of the primary BH falling roughly within the pair instability mass gap, with the highest primary mass being $300_{+60}^{-120} M_\odot$. 5 candidates have median mass ratio $q < 0.5$. Under a prior uniform in effective spin $蠂_{\rm eff}$, 6 candidates have $蠂_{\rm eff} > 0$ at $>95\%$ credibility. We also find that including higher harmonics in our search raises the significance of a few previously reported marginal events (e.g., GW190711_030756). While our new candidate events have modest false alarm rates ($\gtrsim 1.6 $/yr), a population inference study including these can better inform the parameter space of BHs corresponding to the pair instability mass gap, high redshifts, positive effective spins and asymmetric mass ratios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.06631v1-abstract-full').style.display = 'none'; document.getElementById('2312.06631v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15+7 pages, 6+5 figures. Our event catalog (including sub-threshold events) and the samples from our PE runs are available at https://github.com/JayWadekar/GW_higher_harmonics_search</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.06061">arXiv:2311.06061</a> <span> [<a href="https://arxiv.org/pdf/2311.06061">pdf</a>, <a href="https://arxiv.org/format/2311.06061">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.111.024049">10.1103/PhysRevD.111.024049 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New binary black hole mergers in the LIGO-Virgo O3b data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+A+K">Ajit Kumar Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.06061v3-abstract-short" style="display: inline;"> We report the detection of 6 new candidate binary black hole (BBH) merger signals in the publicly released data from the second half of the third observing run (O3b) of advanced LIGO and advanced Virgo. The LIGO-Virgo-KAGRA (LVK) collaboration reported 35 compact binary coalescences (CBCs) in their analysis of the O3b data [1], with 30 BBH mergers having coincidence in the Hanford and Livingston d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06061v3-abstract-full').style.display = 'inline'; document.getElementById('2311.06061v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.06061v3-abstract-full" style="display: none;"> We report the detection of 6 new candidate binary black hole (BBH) merger signals in the publicly released data from the second half of the third observing run (O3b) of advanced LIGO and advanced Virgo. The LIGO-Virgo-KAGRA (LVK) collaboration reported 35 compact binary coalescences (CBCs) in their analysis of the O3b data [1], with 30 BBH mergers having coincidence in the Hanford and Livingston detectors. We confirm 17 of these for a total of 23 detections in our analysis of the Hanford-Livingston coincident O3b data. We identify candidates using a search pipeline employing aligned-spin quadrupole-only waveforms. Our pipeline is similar to the one used in our O3a coincident analysis [2], except for a few improvements in the veto procedure and the ranking statistic, and we continue to use an astrophysical probability of one half as our detection threshold, following the approach of the LVK catalogs. Most of the new candidates reported in this work are placed in the upper and lower-mass gap of the black hole (BH) mass distribution. We also identify a possible neutron star-black hole (NSBH) merger. We expect these events to help inform the black hole mass and spin distributions inferred in a full population analysis. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06061v3-abstract-full').style.display = 'none'; document.getElementById('2311.06061v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 12 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 111, 024049 (2025) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.15233">arXiv:2310.15233</a> <span> [<a href="https://arxiv.org/pdf/2310.15233">pdf</a>, <a href="https://arxiv.org/format/2310.15233">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.110.084035">10.1103/PhysRevD.110.084035 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New approach to template banks of gravitational waves with higher harmonics: Reducing matched-filtering cost by over an order of magnitude </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Mehta%2C+A+K">Ajit Kumar Mehta</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.15233v2-abstract-short" style="display: inline;"> Searches for gravitational wave events use models, or templates, for the signals of interest. The templates used in current searches in the LIGO-Virgo-Kagra (LVK) data model the dominant quadrupole mode $(\ell,|m|)=(2,2)$ of the signals, and omit sub-dominant higher-order modes (HM) such as $(\ell,|m|)=(3,3)$, $(4,4)$, which are predicted by general relativity. This omission reduces search sensiti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.15233v2-abstract-full').style.display = 'inline'; document.getElementById('2310.15233v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.15233v2-abstract-full" style="display: none;"> Searches for gravitational wave events use models, or templates, for the signals of interest. The templates used in current searches in the LIGO-Virgo-Kagra (LVK) data model the dominant quadrupole mode $(\ell,|m|)=(2,2)$ of the signals, and omit sub-dominant higher-order modes (HM) such as $(\ell,|m|)=(3,3)$, $(4,4)$, which are predicted by general relativity. This omission reduces search sensitivity to black hole mergers in interesting parts of parameter space, such as systems with high masses and asymmetric mass-ratios. We develop a new strategy to include HM in template banks: instead of making templates containing a combination of different modes, we separately store normalized templates corresponding to $(2,2)$, $(3,3)$ and $(4,4)$ modes. To model aligned-spin $(3,3)$, $(4,4)$ waveforms corresponding to a given $(2,2)$ waveform, we use a combination of post-Newtonian formulae and machine learning tools. In the matched filtering stage, one can filter each mode separately with the data and collect the timeseries of signal-to-noise ratios (SNR). This leads to a HM template bank whose matched-filtering cost is just $\approx 3\times$ that of a quadrupole-only search (as opposed to $\approx\! 100 \times$ in previously proposed HM search methods). Our method is effectual and generally applicable for template banks constructed with either stochastic or geometric placement techniques. New GW candidate events that we detect using our HM banks and details for combining the different SNR mode timeseries are presented in accompanying papers: Wadekar et al. [1] and [2] respectively. Additionally, we discuss non-linear compression of $(2,2)$-only geometric-placement template banks using machine learning algorithms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.15233v2-abstract-full').style.display = 'none'; document.getElementById('2310.15233v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12+2 pages, 8+1 figures. The code for generating our template banks and reproducing the plots in our paper is publicly available at https://github.com/JayWadekar/gwIAS-HM</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 110, 084035 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.07784">arXiv:2310.07784</a> <span> [<a href="https://arxiv.org/pdf/2310.07784">pdf</a>, <a href="https://arxiv.org/format/2310.07784">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> A 12.4 day periodicity in a close binary system after a supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chen%2C+P">Ping Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">Avishay Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Post%2C+R+S">Richard S. Post</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+C">Chang Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+K+K">Kaustav K. Das</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">Christoffer Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Horesh%2C+A">Assaf Horesh</a>, <a href="/search/astro-ph?searchtype=author&query=Katz%2C+B">Boaz Katz</a>, <a href="/search/astro-ph?searchtype=author&query=Kushnir%2C+D">Doron Kushnir</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S+R">Shri R. Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+D">Dezi Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+X">Xiangkun Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Miller%2C+A+A">Adam A. Miller</a>, <a href="/search/astro-ph?searchtype=author&query=Rose%2C+K">Kovi Rose</a>, <a href="/search/astro-ph?searchtype=author&query=Waxman%2C+E">Eli Waxman</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+S">Sheng Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Yao%2C+Y">Yuhan Yao</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E+C">Eric C. Bellm</a>, <a href="/search/astro-ph?searchtype=author&query=Dekany%2C+R">Richard Dekany</a>, <a href="/search/astro-ph?searchtype=author&query=Drake%2C+A+J">Andrew J. Drake</a> , et al. (15 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.07784v1-abstract-short" style="display: inline;"> Neutron stars and stellar-mass black holes are the remnants of massive star explosions. Most massive stars reside in close binary systems, and the interplay between the companion star and the newly formed compact object has been theoretically explored, but signatures for binarity or evidence for the formation of a compact object during a supernova explosion are still lacking. Here we report a stri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.07784v1-abstract-full').style.display = 'inline'; document.getElementById('2310.07784v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.07784v1-abstract-full" style="display: none;"> Neutron stars and stellar-mass black holes are the remnants of massive star explosions. Most massive stars reside in close binary systems, and the interplay between the companion star and the newly formed compact object has been theoretically explored, but signatures for binarity or evidence for the formation of a compact object during a supernova explosion are still lacking. Here we report a stripped-envelope supernova, SN 2022jli, which shows 12.4-day periodic undulations during the declining light curve. Narrow H$伪$ emission is detected in late-time spectra with concordant periodic velocity shifts, likely arising from hydrogen gas stripped from a companion and accreted onto the compact remnant. A new Fermi/LAT $纬$-ray source is temporally and positionally consistent with SN 2022jli. The observed properties of SN 2022jli, including periodic undulations in the optical light curve, coherent H$伪$ emission shifting, and evidence for association with a $纬$-ray source, point to the explosion of a massive star in a binary system leaving behind a bound compact remnant. Mass accretion from the companion star onto the compact object powers the light curve of the supernova and generates the $纬$-ray emission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.07784v1-abstract-full').style.display = 'none'; document.getElementById('2310.07784v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Nature</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.05626">arXiv:2308.05626</a> <span> [<a href="https://arxiv.org/pdf/2308.05626">pdf</a>, <a href="https://arxiv.org/format/2308.05626">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> A linearized approach to radial velocity extraction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shahaf%2C+S">Sahar Shahaf</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.05626v2-abstract-short" style="display: inline;"> High-precision radial velocity (RV) measurements are crucial for exoplanet detection and characterisation. Efforts to achieve ~10 cm/s precision have been made over the recent decades, with significant advancements in instrumentation, data reduction techniques, and statistical inference methods. However, despite these efforts, RV precision is currently limited to ~50 cm/s. This value exceeds state… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.05626v2-abstract-full').style.display = 'inline'; document.getElementById('2308.05626v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.05626v2-abstract-full" style="display: none;"> High-precision radial velocity (RV) measurements are crucial for exoplanet detection and characterisation. Efforts to achieve ~10 cm/s precision have been made over the recent decades, with significant advancements in instrumentation, data reduction techniques, and statistical inference methods. However, despite these efforts, RV precision is currently limited to ~50 cm/s. This value exceeds state-of-the-art spectrographs' expected instrumental noise floor and is mainly attributed to RV signals induced by stellar variability. In this work, we propose a factorisation method to overcome this limitation. The factorisation is particularly suitable for controlling the effect of localised changes in the stellar emission profile, assuming some smooth function of a few astrophysical parameters governs them. We use short-time Fourier transforms (STFT) to infer the RV in a procedure equivalent to least-squares minimisation in the wavelength domain and demonstrate the effectiveness of our method in treating arbitrary temperature fluctuations on the star's surface. The proposed prescription can be naturally generalised to account for other effects, either intrinsic to the star, such as magnetic fields, or extrinsic to it, such as telluric contamination. As a proof-of-concept, we empirically derive a set of factorisation terms describing the Solar centre-to-limb variation and apply them to a set of realistic SOAP-GPU spectral simulations. We discuss the method's capability to mitigate variability-induced RV signals and its potential extensions to serve as a tomographic tool. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.05626v2-abstract-full').style.display = 'none'; document.getElementById('2308.05626v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 9 figures. Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.07914">arXiv:2306.07914</a> <span> [<a href="https://arxiv.org/pdf/2306.07914">pdf</a>, <a href="https://arxiv.org/format/2306.07914">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Detecting Fast Radio Bursts with Spectral Structure using the Continuous Forward Algorithm </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+P">Pravir Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Law%2C+C+J">Casey J. Law</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.07914v2-abstract-short" style="display: inline;"> Detecting fast radio bursts (FRBs) with frequency-dependent intensity remains a challenge, as existing search algorithms do not account for the spectral shape, potentially leading to non-detections. We propose a novel detection statistic, which we call the Kalman detector, that improves the sensitivity of FRB signal detection by incorporating spectral shape information. The detection statistic is… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.07914v2-abstract-full').style.display = 'inline'; document.getElementById('2306.07914v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.07914v2-abstract-full" style="display: none;"> Detecting fast radio bursts (FRBs) with frequency-dependent intensity remains a challenge, as existing search algorithms do not account for the spectral shape, potentially leading to non-detections. We propose a novel detection statistic, which we call the Kalman detector, that improves the sensitivity of FRB signal detection by incorporating spectral shape information. The detection statistic is based on an optimal matched filter, marginalizing over all possible intensity functions, weighted by a random walk probability distribution, considering some decorrelation bandwidth. Our analysis of previously detected FRBs demonstrates that the Kalman score provides a comparable yet independent source of information for bursts with significant spectral structure, and the sensitivity improvement is of the order 0%--200% with a median improvement of 20%. We also applied the Kalman detector to existing data from FRB 20201124A and detected two new repeat bursts that were previously missed. Furthermore, we suggest a practical implementation for real-time surveys by employing a low significance soft-trigger from initial flux integration-based detection algorithms. The Kalman detector has the potential to significantly enhance FRB detection capabilities and enable new insights into the spectral properties of these enigmatic astrophysical phenomena. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.07914v2-abstract-full').style.display = 'none'; document.getElementById('2306.07914v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 8 figures; accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.00050">arXiv:2306.00050</a> <span> [<a href="https://arxiv.org/pdf/2306.00050">pdf</a>, <a href="https://arxiv.org/format/2306.00050">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</span> </div> </div> <p class="title is-5 mathjax"> In Pursuit of Love: First Templated Search for Compact Objects with Large Tidal Deformabilities in the LIGO-Virgo Data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chia%2C+H+S">Horng Sheng Chia</a>, <a href="/search/astro-ph?searchtype=author&query=Edwards%2C+T+D+P">Thomas D. P. Edwards</a>, <a href="/search/astro-ph?searchtype=author&query=Wadekar%2C+D">Digvijay Wadekar</a>, <a href="/search/astro-ph?searchtype=author&query=Zimmerman%2C+A">Aaron Zimmerman</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.00050v1-abstract-short" style="display: inline;"> We report results on the first matched-filtering search for binaries with compact objects having large tidal deformabilities in the LIGO-Virgo gravitational wave (GW) data. The tidal deformability of a body is quantified by the ``Love number" $螞\propto \hskip 1pt (r/m)^5$, where $r/m$ is the body's (inverse) compactness. Due to its strong dependence on compactness, the $螞$ of larger-sized compact… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.00050v1-abstract-full').style.display = 'inline'; document.getElementById('2306.00050v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.00050v1-abstract-full" style="display: none;"> We report results on the first matched-filtering search for binaries with compact objects having large tidal deformabilities in the LIGO-Virgo gravitational wave (GW) data. The tidal deformability of a body is quantified by the ``Love number" $螞\propto \hskip 1pt (r/m)^5$, where $r/m$ is the body's (inverse) compactness. Due to its strong dependence on compactness, the $螞$ of larger-sized compact objects can easily be many orders of magnitude greater than those of black holes and neutron stars, leaving phase shifts which are sufficiently large for these binaries to be missed by binary black hole (BBH) templated searches. In this paper, we conduct a search using inspiral-only waveforms with zero spins but finite tides, with the search space covering chirp masses $3 M_\odot < \mathcal{M} < 15 M_\odot$ and effective tidal deformabilities $10^2 \lesssim \tilde螞 \lesssim 10^6$. We find no statistically significant GW candidates. This null detection implies an upper limit on the merger rate of such binaries in the range $[1-300] \hskip 2pt \text{Gpc}^{-3} \text{year}^{-1}$, depending on $\mathcal{M}$ and $\tilde螞$. While our constraints are model agnostic, we discuss the implications on beyond the Standard Model scenarios that give rise to boson stars and superradiant clouds. Using inspiral-only waveforms we recover many of the BBH signals which were previously identified with full inspiral-merger-ringdown templates. We also constrain the Love number of black holes to $螞\lesssim 10^3$ at the 90\% credible interval. Our work is the first-ever dedicated template-based search for compact objects that are not only black holes and neutron stars. Additionally, our work demonstrates a novel way of finding new physics in GW data, widening the scope of potential discovery to previously unexplored parameter space. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.00050v1-abstract-full').style.display = 'none'; document.getElementById('2306.00050v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">42+11 pages, 12 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.14482">arXiv:2304.14482</a> <span> [<a href="https://arxiv.org/pdf/2304.14482">pdf</a>, <a href="https://arxiv.org/format/2304.14482">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> ULTRASAT: A wide-field time-domain UV space telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shvartzvald%2C+Y">Y. Shvartzvald</a>, <a href="/search/astro-ph?searchtype=author&query=Waxman%2C+E">E. Waxman</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">A. Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">E. O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Ben-Ami%2C+S">S. Ben-Ami</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Kowalski%2C+M">M. Kowalski</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%BChler%2C+R">R. B眉hler</a>, <a href="/search/astro-ph?searchtype=author&query=Worm%2C+S">S. Worm</a>, <a href="/search/astro-ph?searchtype=author&query=Rhoads%2C+J+E">J. E. Rhoads</a>, <a href="/search/astro-ph?searchtype=author&query=Arcavi%2C+I">I. Arcavi</a>, <a href="/search/astro-ph?searchtype=author&query=Maoz%2C+D">D. Maoz</a>, <a href="/search/astro-ph?searchtype=author&query=Polishook%2C+D">D. Polishook</a>, <a href="/search/astro-ph?searchtype=author&query=Stone%2C+N">N. Stone</a>, <a href="/search/astro-ph?searchtype=author&query=Trakhtenbrot%2C+B">B. Trakhtenbrot</a>, <a href="/search/astro-ph?searchtype=author&query=Ackermann%2C+M">M. Ackermann</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonson%2C+O">O. Aharonson</a>, <a href="/search/astro-ph?searchtype=author&query=Birnholtz%2C+O">O. Birnholtz</a>, <a href="/search/astro-ph?searchtype=author&query=Chelouche%2C+D">D. Chelouche</a>, <a href="/search/astro-ph?searchtype=author&query=Guetta%2C+D">D. Guetta</a>, <a href="/search/astro-ph?searchtype=author&query=Hallakoun%2C+N">N. Hallakoun</a>, <a href="/search/astro-ph?searchtype=author&query=Horesh%2C+A">A. Horesh</a>, <a href="/search/astro-ph?searchtype=author&query=Kushnir%2C+D">D. Kushnir</a>, <a href="/search/astro-ph?searchtype=author&query=Mazeh%2C+T">T. Mazeh</a>, <a href="/search/astro-ph?searchtype=author&query=Nordin%2C+J">J. Nordin</a> , et al. (19 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.14482v1-abstract-short" style="display: inline;"> The Ultraviolet Transient Astronomy Satellite (ULTRASAT) is scheduled to be launched to geostationary orbit in 2026. It will carry a telescope with an unprecedentedly large field of view (204 deg$^2$) and NUV (230-290nm) sensitivity (22.5 mag, 5$蟽$, at 900s). ULTRASAT will conduct the first wide-field survey of transient and variable NUV sources and will revolutionize our ability to study the hot… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.14482v1-abstract-full').style.display = 'inline'; document.getElementById('2304.14482v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.14482v1-abstract-full" style="display: none;"> The Ultraviolet Transient Astronomy Satellite (ULTRASAT) is scheduled to be launched to geostationary orbit in 2026. It will carry a telescope with an unprecedentedly large field of view (204 deg$^2$) and NUV (230-290nm) sensitivity (22.5 mag, 5$蟽$, at 900s). ULTRASAT will conduct the first wide-field survey of transient and variable NUV sources and will revolutionize our ability to study the hot transient universe: It will explore a new parameter space in energy and time-scale (months long light-curves with minutes cadence), with an extra-Galactic volume accessible for the discovery of transient sources that is $>$300 times larger than that of GALEX and comparable to that of LSST. ULTRASAT data will be transmitted to the ground in real-time, and transient alerts will be distributed to the community in $<$15 min, enabling a vigorous ground-based follow-up of ULTRASAT sources. ULTRASAT will also provide an all-sky NUV image to $>$23.5 AB mag, over 10 times deeper than the GALEX map. Two key science goals of ULTRASAT are the study of mergers of binaries involving neutron stars, and supernovae: With a large fraction ($>$50%) of the sky instantaneously accessible, fast (minutes) slewing capability and a field-of-view that covers the error ellipses expected from GW detectors beyond 2025, ULTRASAT will rapidly detect the electromagnetic emission following BNS/NS-BH mergers identified by GW detectors, and will provide continuous NUV light-curves of the events; ULTRASAT will provide early (hour) detection and continuous high (minutes) cadence NUV light curves for hundreds of core-collapse supernovae, including for rarer supernova progenitor types. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.14482v1-abstract-full').style.display = 'none'; document.getElementById('2304.14482v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">40 pages, 16 figures, 3 tables. Submitted to the AAS journals</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.04796">arXiv:2304.04796</a> <span> [<a href="https://arxiv.org/pdf/2304.04796">pdf</a>, <a href="https://arxiv.org/ps/2304.04796">ps</a>, <a href="https://arxiv.org/format/2304.04796">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1538-3873/acd8f0">10.1088/1538-3873/acd8f0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Large Array Survey Telescope -- System Overview and Performances </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">E. O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Ben-Ami%2C+S">S. Ben-Ami</a>, <a href="/search/astro-ph?searchtype=author&query=Polishook%2C+D">D. Polishook</a>, <a href="/search/astro-ph?searchtype=author&query=Segre%2C+E">E. Segre</a>, <a href="/search/astro-ph?searchtype=author&query=Blumenzweig%2C+A">A. Blumenzweig</a>, <a href="/search/astro-ph?searchtype=author&query=Strotjohann%2C+N+L">N. L. Strotjohann</a>, <a href="/search/astro-ph?searchtype=author&query=Yaron%2C+O">O. Yaron</a>, <a href="/search/astro-ph?searchtype=author&query=Shani%2C+Y+M">Y. M. Shani</a>, <a href="/search/astro-ph?searchtype=author&query=Nachshon%2C+S">S. Nachshon</a>, <a href="/search/astro-ph?searchtype=author&query=Shvartzvald%2C+Y">Y. Shvartzvald</a>, <a href="/search/astro-ph?searchtype=author&query=Hershko%2C+O">O. Hershko</a>, <a href="/search/astro-ph?searchtype=author&query=Engel%2C+M">M. Engel</a>, <a href="/search/astro-ph?searchtype=author&query=Segre%2C+M">M. Segre</a>, <a href="/search/astro-ph?searchtype=author&query=Segev%2C+N">N. Segev</a>, <a href="/search/astro-ph?searchtype=author&query=Zimmerman%2C+E">E. Zimmerman</a>, <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">G. Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Judkovsky%2C+Y">Y. Judkovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">A. Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">B. Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Waxman%2C+E">E. Waxman</a>, <a href="/search/astro-ph?searchtype=author&query=Kushnir%2C+D">D. Kushnir</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+P">P. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Azaria%2C+R">R. Azaria</a>, <a href="/search/astro-ph?searchtype=author&query=Manulis%2C+I">I. Manulis</a>, <a href="/search/astro-ph?searchtype=author&query=Diner%2C+O">O. Diner</a> , et al. (16 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.04796v1-abstract-short" style="display: inline;"> The Large Array Survey Telescope (LAST) is a wide-field visible-light telescope array designed to explore the variable and transient sky with a high cadence. LAST will be composed of 48, 28-cm f/2.2 telescopes (32 already installed) equipped with full-frame backside-illuminated cooled CMOS detectors. Each telescope provides a field of view (FoV) of 7.4 deg^2 with 1.25 arcsec/pix, while the system… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.04796v1-abstract-full').style.display = 'inline'; document.getElementById('2304.04796v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.04796v1-abstract-full" style="display: none;"> The Large Array Survey Telescope (LAST) is a wide-field visible-light telescope array designed to explore the variable and transient sky with a high cadence. LAST will be composed of 48, 28-cm f/2.2 telescopes (32 already installed) equipped with full-frame backside-illuminated cooled CMOS detectors. Each telescope provides a field of view (FoV) of 7.4 deg^2 with 1.25 arcsec/pix, while the system FoV is 355 deg^2 in 2.9 Gpix. The total collecting area of LAST, with 48 telescopes, is equivalent to a 1.9-m telescope. The cost-effectiveness of the system (i.e., probed volume of space per unit time per unit cost) is about an order of magnitude higher than most existing and under-construction sky surveys. The telescopes are mounted on 12 separate mounts, each carrying four telescopes. This provides significant flexibility in operating the system. The first LAST system is under construction in the Israeli Negev Desert, with 32 telescopes already deployed. We present the system overview and performances based on the system commissioning data. The Bp 5-sigma limiting magnitude of a single 28-cm telescope is about 19.6 (21.0), in 20 s (20x20 s). Astrometric two-axes precision (rms) at the bright-end is about 60 (30)\,mas in 20\,s (20x20 s), while absolute photometric calibration, relative to GAIA, provides ~10 millimag accuracy. Relative photometric precision, in a single 20 s (320 s) image, at the bright-end measured over a time scale of about 60 min is about 3 (1) millimag. We discuss the system science goals, data pipelines, and the observatory control system in companion publications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.04796v1-abstract-full').style.display = 'none'; document.getElementById('2304.04796v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to PASP, 15pp</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.12020">arXiv:2303.12020</a> <span> [<a href="https://arxiv.org/pdf/2303.12020">pdf</a>, <a href="https://arxiv.org/format/2303.12020">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> A search for Kuiper Belt occultations using the Weizmann Fast Astronomical Survey Telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">Guy Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Polishook%2C+D">David Polishook</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ben-Ami%2C+S">Sagi Ben-Ami</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.12020v2-abstract-short" style="display: inline;"> Measuring the size distribution of small (km-scale) KBOs can help constrain models of Solar System formation and planetary migration. Such small, distant bodies are hard to detect with current or planned telescopes, but can be identified as sub-second occultations of background stars. We present the analysis of data from the Weizmann Fast Astronomical Survey Telescope (W-FAST), consisting of fast… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12020v2-abstract-full').style.display = 'inline'; document.getElementById('2303.12020v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.12020v2-abstract-full" style="display: none;"> Measuring the size distribution of small (km-scale) KBOs can help constrain models of Solar System formation and planetary migration. Such small, distant bodies are hard to detect with current or planned telescopes, but can be identified as sub-second occultations of background stars. We present the analysis of data from the Weizmann Fast Astronomical Survey Telescope (W-FAST), consisting of fast photometry of ~10^6 star hours at a frame rate of 10-25 Hz. Our pipeline utilizes a matched-filter approach with a large template bank, including red-noise treatment, and injection of simulated events for estimating the detection efficiency. The KBO radius at which our survey is 10% (50%) efficient is 1.1 (2.0) km. The data from 2020-2021 observing seasons were analyzed and no occultations were identified. We discuss a sample of sub-second false-positive events, both occultation-like and flare-like, which are still not fully understood but could be instructive for future surveys looking for short-duration events. We use our null-detection result to set limits on the km-scale KBO number density. Our individual radius bin limits are consistent with most previous works, with N(r>1km) <=10^6 deg^-2 (95% confidence limit). Our integrated (all size) limits, assuming a power law normalized to large (~45 km) KBOs gives a power law index q<3.93 (95% confidence limit). Finally, our results are in tension with a recently reported KBO detection from the ground, at the p=4x10^-4 level. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12020v2-abstract-full').style.display = 'none'; document.getElementById('2303.12020v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.11275">arXiv:2303.11275</a> <span> [<a href="https://arxiv.org/pdf/2303.11275">pdf</a>, <a href="https://arxiv.org/format/2303.11275">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> A reduction procedure and pipeline for the detection of trans-Neptunian objects using occultations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">Guy Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.11275v2-abstract-short" style="display: inline;"> Kuiper belt objects smaller than a few kilometers are difficult to observe directly. They can be detected when they randomly occult a background star. Close to the ecliptic plane, each star is occulted once every tens of thousands of hours, and occultations typically last for less than a second. We present an algorithm, and companion pipeline, for detection of diffractive occultation events. Our a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.11275v2-abstract-full').style.display = 'inline'; document.getElementById('2303.11275v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.11275v2-abstract-full" style="display: none;"> Kuiper belt objects smaller than a few kilometers are difficult to observe directly. They can be detected when they randomly occult a background star. Close to the ecliptic plane, each star is occulted once every tens of thousands of hours, and occultations typically last for less than a second. We present an algorithm, and companion pipeline, for detection of diffractive occultation events. Our approach includes: cleaning the data; an efficient and optimal matched filtering of the light-curves with a template bank of diffractive occultations; treating the red-noise in the light-curves; injection of simulated events for efficiency estimation; and applying data quality cuts. We discuss human vetting of the candidate events in a blinded way to reduce bias caused by the human-in-the-loop. We present Markov Chain Monte Carlo tools to estimate the parameters of candidate occultations, and test them on simulated events. This pipeline is used by the W-FAST. The methods discussed here can be applied to searches for other Trans-Neptunian objects, albeit with larger radii that correspond to a larger diffraction length scale. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.11275v2-abstract-full').style.display = 'none'; document.getElementById('2303.11275v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.00010">arXiv:2303.00010</a> <span> [<a href="https://arxiv.org/pdf/2303.00010">pdf</a>, <a href="https://arxiv.org/format/2303.00010">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Direct detection of supernova progenitor stars with ZTF and LSST </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Strotjohann%2C+N+L">Nora L. Strotjohann</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">Avishay Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+P">Ping Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Yaron%2C+O">Ofer Yaron</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Rehemtulla%2C+N">Nabeel Rehemtulla</a>, <a href="/search/astro-ph?searchtype=author&query=Gris%2C+P">Phillipe Gris</a>, <a href="/search/astro-ph?searchtype=author&query=Masci%2C+F+J">Frank J. Masci</a>, <a href="/search/astro-ph?searchtype=author&query=Rusholme%2C+B">Ben Rusholme</a>, <a href="/search/astro-ph?searchtype=author&query=Purdum%2C+J">Josiah Purdum</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.00010v2-abstract-short" style="display: inline;"> The direct detection of core-collapse supernova (SN) progenitor stars is a powerful way of probing the last stages of stellar evolution. However, detections in archival Hubble Space Telescope images are limited to about one per year. Here, we explore whether we can increase the detection rate by using data from ground-based wide-field surveys. Due to crowding and atmospheric blurring, progenitor s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.00010v2-abstract-full').style.display = 'inline'; document.getElementById('2303.00010v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.00010v2-abstract-full" style="display: none;"> The direct detection of core-collapse supernova (SN) progenitor stars is a powerful way of probing the last stages of stellar evolution. However, detections in archival Hubble Space Telescope images are limited to about one per year. Here, we explore whether we can increase the detection rate by using data from ground-based wide-field surveys. Due to crowding and atmospheric blurring, progenitor stars can typically not be identified in pre-explosion images alone. Instead, we combine many pre-SN and late-time images to search for the disappearance of the progenitor star. As a proof of concept, we implement our search for ZTF data. For a few hundred images, we achieve limiting magnitudes of about 23 mag in the g and r band. However, no progenitor stars or long-lived outbursts are detected for 29 SNe within z<0.01, and the ZTF limits are typically several magnitudes less constraining than detected progenitors in the literature. Next, we estimate progenitor detection rates for the Legacy Survey of Space and Time (LSST) with the Vera C. Rubin telescope by simulating a population of nearby SNe. The background from bright host galaxies reduces the nominal LSST sensitivity by, on average, 0.4 mag. Over the ten-year survey, we expect the detection of about 50 red supergiant progenitors and several yellow and blue supergiants. The progenitors of SNe Ib and Ic are detectable if they are brighter than -4.7 mag or -4.0 mag in the LSST i band, respectively. In addition, we expect the detection of hundreds of pre-SN outbursts depending on their brightness and duration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.00010v2-abstract-full').style.display = 'none'; document.getElementById('2303.00010v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ. Comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.08303">arXiv:2208.08303</a> <span> [<a href="https://arxiv.org/pdf/2208.08303">pdf</a>, <a href="https://arxiv.org/format/2208.08303">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/ad0b6f">10.3847/1538-3881/ad0b6f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Precision speckle pattern reconstruction for high contrast imaging </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gazith%2C+D">Dotan Gazith</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.08303v1-abstract-short" style="display: inline;"> In High Contrast Imaging, a large instrumental, technological and algorithmic effort is made to reduce residual speckle noise and improve the detection capabilities. In this work, we explore the potential of using a precise physical description of speckle images, in conjunction with the optimal detection statistic to perform High Contrast Imaging. Our method uses short-exposure speckle images, rec… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.08303v1-abstract-full').style.display = 'inline'; document.getElementById('2208.08303v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.08303v1-abstract-full" style="display: none;"> In High Contrast Imaging, a large instrumental, technological and algorithmic effort is made to reduce residual speckle noise and improve the detection capabilities. In this work, we explore the potential of using a precise physical description of speckle images, in conjunction with the optimal detection statistic to perform High Contrast Imaging. Our method uses short-exposure speckle images, reconstructing the Point Spread Function (PSF) of each image with phase retrieval algorithms. Using the reconstructed PSF's we calculate the optimal detection statistic for all images. We analyze the arising bias due to the use of a reconstructed PSF and correct for it completely up to its accumulation over $10^4$ images. We measure in simulations the method's sensitivity loss due to overfitting in the reconstruction process and get to an estimated 5$蟽$ detection limit of $5\times 10^{-7}$ flux ratio at angular separations of $0.1 -0.5^{\prime\prime}$ for a $1h$ observation of Sirius A with a 2m-telescope. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.08303v1-abstract-full').style.display = 'none'; document.getElementById('2208.08303v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 5 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.03508">arXiv:2207.03508</a> <span> [<a href="https://arxiv.org/pdf/2207.03508">pdf</a>, <a href="https://arxiv.org/format/2207.03508">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.106.123015">10.1103/PhysRevD.106.123015 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Removing degeneracy and multimodality in gravitational wave source parameters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Islam%2C+T">Tousif Islam</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.03508v2-abstract-short" style="display: inline;"> Quasicircular binary black hole mergers are described by 15 parameters, of which gravitational wave observations can typically constrain only $\sim 10$ independent combinations to varying degree. In this work, we devise coordinates that remove correlations, and disentangle well- and poorly-measured quantities. Additionally, we identify approximate discrete symmetries in the posterior as the primar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.03508v2-abstract-full').style.display = 'inline'; document.getElementById('2207.03508v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.03508v2-abstract-full" style="display: none;"> Quasicircular binary black hole mergers are described by 15 parameters, of which gravitational wave observations can typically constrain only $\sim 10$ independent combinations to varying degree. In this work, we devise coordinates that remove correlations, and disentangle well- and poorly-measured quantities. Additionally, we identify approximate discrete symmetries in the posterior as the primary cause of multimodality, and design a method to tackle this type of multimodality. The resulting posteriors have little structure and can be sampled efficiently and robustly. We provide a Python package for parameter estimation, cogwheel, that implements these methods together with other algorithms for accelerating the inference process. One of the coordinates we introduce is a spin azimuth that is measured remarkably well in several events. We suggest this might be a sensitive indicator of orbital precession, and we anticipate that it will shed light on the occurrence of spin-orbit misalignment in nature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.03508v2-abstract-full').style.display = 'none'; document.getElementById('2207.03508v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 13 figures, 1 table. Matches version accepted for publication in Phys. Rev. D</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.02398">arXiv:2204.02398</a> <span> [<a href="https://arxiv.org/pdf/2204.02398">pdf</a>, <a href="https://arxiv.org/format/2204.02398">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac960">10.1093/mnras/stac960 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> fBLS -- a fast-folding BLS algorithm </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shahaf%2C+S">Sahar Shahaf</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Mazeh%2C+T">Tsevi Mazeh</a>, <a href="/search/astro-ph?searchtype=author&query=Faigler%2C+S">Simchon Faigler</a>, <a href="/search/astro-ph?searchtype=author&query=Ivashtenko%2C+O">Oryna Ivashtenko</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.02398v1-abstract-short" style="display: inline;"> We present fBLS -- a novel fast-folding technique to search for transiting planets, based on the fast-folding algorithm (FFA), which is extensively used in pulsar astronomy. For a given lightcurve with $N$ data points, fBLS simultaneously produces all the binned phase-folded lightcurves for an array of $N_p$ trial periods. For each folded lightcurve produced by fBLS, the algorithm generates the st… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.02398v1-abstract-full').style.display = 'inline'; document.getElementById('2204.02398v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.02398v1-abstract-full" style="display: none;"> We present fBLS -- a novel fast-folding technique to search for transiting planets, based on the fast-folding algorithm (FFA), which is extensively used in pulsar astronomy. For a given lightcurve with $N$ data points, fBLS simultaneously produces all the binned phase-folded lightcurves for an array of $N_p$ trial periods. For each folded lightcurve produced by fBLS, the algorithm generates the standard BLS periodogram and statistics. The number of performed arithmetic operations is $\mathcal{O}\big(N_p\cdot\log N_p \big)$, while regular BLS requires $\mathcal{O}\big(N_p\cdot N\big)$ operations. fBLS can be used to detect small rocky transiting planets, with periods shorter than one day, a period range for which the computation is extensive. We demonstrate the capabilities of the new algorithm by performing a preliminary fBLS search for planets with ultra-short periods in the Kepler main-sequence lightcurves. In addition, we developed a simplistic signal validation scheme for vetting the planet candidates. This two-stage preliminary search identified all known ultra-short planet candidates and found three new ones. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.02398v1-abstract-full').style.display = 'none'; document.getElementById('2204.02398v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 5 figures, MNRAS accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.02252">arXiv:2201.02252</a> <span> [<a href="https://arxiv.org/pdf/2201.02252">pdf</a>, <a href="https://arxiv.org/format/2201.02252">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.106.043009">10.1103/PhysRevD.106.043009 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New binary black hole mergers in the LIGO--Virgo O3a data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Mushkin%2C+J">Jonathan Mushkin</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2201.02252v3-abstract-short" style="display: inline;"> We report the detection of ten new binary black hole (BBH) mergers in the publicly released data from the the first half of the third observing run (O3a) of advanced LIGO and advanced Virgo. We identify candidates using an updated version of the IAS search pipeline and compile a catalog of signals that pass a significance threshold of astrophysical probability greater than 0.5 (following the GWTC-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.02252v3-abstract-full').style.display = 'inline'; document.getElementById('2201.02252v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.02252v3-abstract-full" style="display: none;"> We report the detection of ten new binary black hole (BBH) mergers in the publicly released data from the the first half of the third observing run (O3a) of advanced LIGO and advanced Virgo. We identify candidates using an updated version of the IAS search pipeline and compile a catalog of signals that pass a significance threshold of astrophysical probability greater than 0.5 (following the GWTC-2.1 and 3-OGC catalogs). The updated IAS pipeline is sensitive to a larger region of parameter space, applies a template prior that accounts for different search volume as a function of intrinsic parameters, and uses an improved coherent detection statistic that optimally combines the data from the Hanford and Livingston detectors. Among the ten new events, we observe interesting astrophysical scenarios including sources with confidently large effective spin parameters in both the positive and negative directions, high-mass black holes that are difficult to form in stellar collapse models due to (pulsational) pair instability, and low-mass mergers that bridge the gap between neutron stars and the lightest observed black holes. We infer source parameters in the upper and lower black hole mass gaps with both extreme and near-unity mass ratios, and one of the possible neutron star--black hole mergers is well localized for electromagnetic counterpart searches. We detect all of the GWTC-2.1 BBH mergers with coincident data in Hanford and Livingston except for three loud events that get vetoed, which is compatible with the false-positive rate of our veto procedure, and three that fall below the detection threshold. We also return to significance the event GW190909_114149, which was reduced to a sub-threshold trigger after its initial appearance in GWTC-2. This amounts to a total of 42 BBH mergers detected by our pipeline's search of the coincident Hanford--Livingston O3a data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.02252v3-abstract-full').style.display = 'none'; document.getElementById('2201.02252v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 6 figures, 2 tables, 4 appendices (15 pages, 15 figures), latest version has minor updates to match the version published in Physical Review D</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 106, 043009 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.13821">arXiv:2106.13821</a> <span> [<a href="https://arxiv.org/pdf/2106.13821">pdf</a>, <a href="https://arxiv.org/format/2106.13821">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.104.083036">10.1103/PhysRevD.104.083036 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Mapping the Likelihood of GW190521 with Diverse Mass and Spin Priors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Chia%2C+H+S">Horng Sheng Chia</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.13821v2-abstract-short" style="display: inline;"> We map the likelihood of GW190521, the heaviest detected binary black hole (BBH) merger, by sampling under different mass and spin priors designed to be uninformative. We find that a source-frame total mass of $\sim$$150 M_{\odot}$ is consistently supported, but posteriors in mass ratio and spin depend critically on the choice of priors. We confirm that the likelihood has a multi-modal structure w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13821v2-abstract-full').style.display = 'inline'; document.getElementById('2106.13821v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.13821v2-abstract-full" style="display: none;"> We map the likelihood of GW190521, the heaviest detected binary black hole (BBH) merger, by sampling under different mass and spin priors designed to be uninformative. We find that a source-frame total mass of $\sim$$150 M_{\odot}$ is consistently supported, but posteriors in mass ratio and spin depend critically on the choice of priors. We confirm that the likelihood has a multi-modal structure with peaks in regions of mass ratio representing very different astrophysical scenarios. The unequal-mass region ($m_2 / m_1 < 0.3$) has an average likelihood $\sim$$e^6$ times larger than the equal-mass region and a maximum likelihood $\sim$$e^2$ larger. Using ensembles of samples across priors, we examine the implications of qualitatively different BBH sources that fit the data. We find that the equal-mass solution has poorly constrained spins and at least one black hole mass that is difficult to form via stellar collapse due to (pulsational) pair instability. The unequal-mass solution can avoid this mass gap entirely but requires a negative effective spin and a precessing primary. Both of these scenarios are more easily produced by dynamical formation channels than field binary co-evolution. Drawing representative samples from each region of the likelihood map, we find a sensitive comoving volume-time $\mathcal{O}(10)$ times larger in the mass gap region than the gap-avoiding region. Accounting for this distance effect, the likelihood still reverses the advantage to favor the gap-avoiding scenario by a factor of $\mathcal{O}(100)$ before including mass and spin priors. Posterior samplers can be driven away from this high-likelihood region by common prior choices meant to be uninformative, making GW190521 parameter inference sensitive to the choice of mass and spin priors. This may be a generic issue for similarly heavy events given current detector sensitivity and waveform degeneracies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13821v2-abstract-full').style.display = 'none'; document.getElementById('2106.13821v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 11 figures, 2 tables, latest version has minor updates to match the version published in Physical Review D</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 104, 083036 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.10580">arXiv:2105.10580</a> <span> [<a href="https://arxiv.org/pdf/2105.10580">pdf</a>, <a href="https://arxiv.org/format/2105.10580">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.104.083010">10.1103/PhysRevD.104.083010 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Distribution of Effective Spins and Masses of Binary Black Holes from the LIGO and Virgo O1-O3a Observing Runs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Chia%2C+H+S">Horng Sheng Chia</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.10580v2-abstract-short" style="display: inline;"> The distribution of effective spin $蠂_{\rm eff}$, a parameter that encodes the degree of spin-orbit alignment in a binary system, has been widely regarded as a robust discriminator between the isolated and dynamical formation pathways for merging binary black holes. Until the recent release of the GWTC-2 catalog, such tests have yielded inconclusive results due to the small number of events with m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.10580v2-abstract-full').style.display = 'inline'; document.getElementById('2105.10580v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.10580v2-abstract-full" style="display: none;"> The distribution of effective spin $蠂_{\rm eff}$, a parameter that encodes the degree of spin-orbit alignment in a binary system, has been widely regarded as a robust discriminator between the isolated and dynamical formation pathways for merging binary black holes. Until the recent release of the GWTC-2 catalog, such tests have yielded inconclusive results due to the small number of events with measurable nonzero spins. In this work, we study the $蠂_{\rm eff}$ distribution of the binary black holes detected in the LIGO-Virgo O1-O3a observing runs. Our focus is on the degree to which the $蠂_{\rm eff}$ distribution is symmetric about $蠂_{\rm eff} = 0$ and whether the data provides support for a population of negative-$蠂_{\rm eff}$ systems. We find that the $蠂_{\rm eff}$ distribution is asymmetric at 95% credibility, with an excess of aligned-spin binary systems ($蠂_{\rm eff}>0$) over anti-aligned ones. Moreover, we find that there is no evidence for negative-$蠂_{\rm eff}$ systems in the current population of binary black holes. Thus, based solely on the $蠂_{\rm eff}$ distribution, dynamical formation is disfavored as being responsible for the entirety of the observed merging binary black holes, while isolated formation remains viable. We also study the mass distribution of the current binary black hole population, confirming that a single truncated power law distribution in the primary source-frame mass, $m_1^{\rm src}$, fails to describe the observations. Instead, we find that the preferred models have a steep feature at $m_1^{\rm src} \sim 40 \,\rm M_\odot$ consistent with a step and an extended, shallow tail to high masses. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.10580v2-abstract-full').style.display = 'none'; document.getElementById('2105.10580v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 6 figures, 4 tables. v2: Minor changes to text and title, reference added, matches version published in PRD</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 104, 083010 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.06486">arXiv:2105.06486</a> <span> [<a href="https://arxiv.org/pdf/2105.06486">pdf</a>, <a href="https://arxiv.org/format/2105.06486">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.106.024009">10.1103/PhysRevD.106.024009 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Signs of Higher Multipoles and Orbital Precession in GW151226 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chia%2C+H+S">Horng Sheng Chia</a>, <a href="/search/astro-ph?searchtype=author&query=Olsen%2C+S">Seth Olsen</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.06486v2-abstract-short" style="display: inline;"> We present a reanalysis of GW151226, the second binary black hole merger discovered by the LIGO--Virgo Collaboration. Previous analysis showed that the best-fit waveform for this event corresponded to the merger of a $\sim 14 \, M_\odot$ black hole with a $\sim 7.5 \, M_\odot$ companion, and the posterior distribution in mass ratio ($q \leq 1$) is rather flat. In this work, we perform parameter es… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.06486v2-abstract-full').style.display = 'inline'; document.getElementById('2105.06486v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.06486v2-abstract-full" style="display: none;"> We present a reanalysis of GW151226, the second binary black hole merger discovered by the LIGO--Virgo Collaboration. Previous analysis showed that the best-fit waveform for this event corresponded to the merger of a $\sim 14 \, M_\odot$ black hole with a $\sim 7.5 \, M_\odot$ companion, and the posterior distribution in mass ratio ($q \leq 1$) is rather flat. In this work, we perform parameter estimation using a waveform model that includes the effects of orbital precession and higher-order radiative multipole modes, and we find that the source parameters of GW151226 shift towards the low $q$ and high effective spin ($蠂_{\rm eff}$) region and that $q$ is better measured. The new solution has a log likelihood roughly two points higher than when either higher multipoles or orbital precession is neglected and can alter the astrophysical interpretation of GW151226. Additionally, we find it useful to use a flat-in-$蠂{\rm eff}$ prior, which does not penalize the large $|蠂_{\rm eff}|$ region, in order to uncover the higher likelihood region for GW151226. Our solution has several interesting properties: (a) the secondary black hole mass is close to the upper limit of the hypothesized lower mass gap of astrophysical black hole population; and (b) orbital precession is driven by the primary black hole spin, which has a dimensionless magnitude as large as $\sim 0.85$ and is tilted away from the orbital angular momentum at an angle of $\sim 57^\circ$. Since GW151226 is a relatively weak signal, an unambiguous claim of the detection of these effects in the signal cannot be made. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.06486v2-abstract-full').style.display = 'none'; document.getElementById('2105.06486v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 6 figures; updated to match published version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.03436">arXiv:2105.03436</a> <span> [<a href="https://arxiv.org/pdf/2105.03436">pdf</a>, <a href="https://arxiv.org/format/2105.03436">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1538-3873/ac0da0">10.1088/1538-3873/ac0da0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Weizmann Fast Astronomical Survey Telescope (W-FAST): System Overview </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">Guy Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Ben-Ami%2C+S">Sagi Ben-Ami</a>, <a href="/search/astro-ph?searchtype=author&query=Segev%2C+N">Noam Segev</a>, <a href="/search/astro-ph?searchtype=author&query=Polishook%2C+D">David Polishook</a>, <a href="/search/astro-ph?searchtype=author&query=Hershko%2C+O">Ofir Hershko</a>, <a href="/search/astro-ph?searchtype=author&query=Diner%2C+O">Oz Diner</a>, <a href="/search/astro-ph?searchtype=author&query=Manulis%2C+I">Ilan Manulis</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">Avishay Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Yaron%2C+O">Ofer Yaron</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.03436v1-abstract-short" style="display: inline;"> A relatively unexplored phase space of transients and stellar variability is that of second and sub-second time-scales. We describe a new optical observatory operating in the Negev desert in Israel, with a 55 cm aperture, a field of view of 2.6x2.6 deg (~7deg^2) equipped with a high frame rate, low read noise, CMOS camera. The system can observe at a frame rate of up to 90HZ (full frame), while no… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.03436v1-abstract-full').style.display = 'inline'; document.getElementById('2105.03436v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.03436v1-abstract-full" style="display: none;"> A relatively unexplored phase space of transients and stellar variability is that of second and sub-second time-scales. We describe a new optical observatory operating in the Negev desert in Israel, with a 55 cm aperture, a field of view of 2.6x2.6 deg (~7deg^2) equipped with a high frame rate, low read noise, CMOS camera. The system can observe at a frame rate of up to 90HZ (full frame), while nominally observations are conducted at 10-25Hz. The data, generated at a rate of over 6Gbits/s at a frame rate of 25Hz, are analyzed in real time. The observatory is fully robotic and capable of autonomously collecting data on a few thousand stars in each field each night. We present the system overview, performance metrics, science objectives, and some first results, e.g., the detection of a high rate of glints from geosynchronous satellites, reported in Nir et al. 2020. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.03436v1-abstract-full').style.display = 'none'; document.getElementById('2105.03436v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 18 figures. Submitted to PASP</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2008.07014">arXiv:2008.07014</a> <span> [<a href="https://arxiv.org/pdf/2008.07014">pdf</a>, <a href="https://arxiv.org/format/2008.07014">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.102.123022">10.1103/PhysRevD.102.123022 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Binary Black Hole Mergers from LIGO/Virgo O1 and O2: Population Inference Combining Confident and Marginal Events </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2008.07014v2-abstract-short" style="display: inline;"> We perform a statistical inference of the astrophysical population of binary black hole (BBH) mergers observed during the first two observing runs of Advanced LIGO and Advanced Virgo, including events reported in the GWTC-1 and IAS catalogs. We derive a novel formalism to fully and consistently account for events of arbitrary significance. We carry out a software injection campaign to obtain a set… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.07014v2-abstract-full').style.display = 'inline'; document.getElementById('2008.07014v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.07014v2-abstract-full" style="display: none;"> We perform a statistical inference of the astrophysical population of binary black hole (BBH) mergers observed during the first two observing runs of Advanced LIGO and Advanced Virgo, including events reported in the GWTC-1 and IAS catalogs. We derive a novel formalism to fully and consistently account for events of arbitrary significance. We carry out a software injection campaign to obtain a set of mock astrophysical events subject to our selection effects, and use the search background to compute the astrophysical probabilities $p_{\rm astro}$ of candidate events for several phenomenological models of the BBH population. We emphasize that the values of $p_{\rm astro}$ depend on both the astrophysical and background models. Finally, we combine the information from individual events to infer the rate, spin, mass, mass-ratio and redshift distributions of the mergers. The existing population does not discriminate between random spins with a spread in the effective spin parameter, and a small but nonzero fraction of events from tidally-torqued stellar progenitors. The mass distribution is consistent with one having a cutoff at $m_{\rm max} = 41^{+10}_{-5}\,\rm M_\odot$, while the mass ratio favors equal masses; the mean mass ratio $\bar q> 0.67$. The rate shows no significant evolution with redshift. We show that the merger rate restricted to BBHs with a primary mass between 20 and $30\, \rm M_\odot$, and a mass ratio $q > 0.5$, and at $z \sim 0.2$, is 1.5 to $5.3\,{\rm Gpc^{-3} yr^{-1}}$ (90\% c.l.); these bounds are model independent and a factor of $\sim 3$ tighter than that on the local rate of all BBH mergers, and hence are a robust constraint on all progenitor models. Including the events in our catalog increases the Fisher information about the BBH population by $\sim 47\%$, and tightens the constraints on population parameters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.07014v2-abstract-full').style.display = 'none'; document.getElementById('2008.07014v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 13 figures. Version accepted for publication in Physical Review D</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 102, 123022 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.12709">arXiv:2007.12709</a> <span> [<a href="https://arxiv.org/pdf/2007.12709">pdf</a>, <a href="https://arxiv.org/format/2007.12709">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> </div> <p class="title is-5 mathjax"> Search for Lensed Gravitational Waves Including Morse Phase Information: An Intriguing Candidate in O2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2007.12709v1-abstract-short" style="display: inline;"> We search for strongly lensed and multiply imaged gravitational wave signals in the second observing run of Advanced LIGO and Advanced Virgo (O2). We exploit a new source of information, the so-called Morse phase, which further mitigates the search background and constrains viable lenses. The best candidate we find is consistent with a strongly lensed signal from a massive binary black hole (BBH)… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.12709v1-abstract-full').style.display = 'inline'; document.getElementById('2007.12709v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.12709v1-abstract-full" style="display: none;"> We search for strongly lensed and multiply imaged gravitational wave signals in the second observing run of Advanced LIGO and Advanced Virgo (O2). We exploit a new source of information, the so-called Morse phase, which further mitigates the search background and constrains viable lenses. The best candidate we find is consistent with a strongly lensed signal from a massive binary black hole (BBH) merger, with three detected images consisting of the previously catalogued events GW170104 and GW170814, and a subthreshold trigger, GWC170620. Given the number of BBH events detected so far, we estimate an overall false alarm probability $\sim 10^{-4}$ for the observed high degree of parameter coincidence between the three events. On the flip side, we measure the Morse phase differences which suggest a complex and atypical lens system, with at least five images including a magnified image at a local maximum of the Fermat potential. The low prior probability for multiple lensed images and the amount of fine tuning required in the lens model reduce the credibility of the lensing hypothesis. The long time delays between lensed images point toward a galaxy cluster lens with an internal velocity dispersion $蟽\sim 650\,{\rm km/s}$, and the observed strain amplitudes imply a likely range $0.4 < z \lesssim 0.7$ for the source redshift. We provide an error ellipse of $\sim 16\,{\rm deg}^2$ for the sky location of the source together with additional specific constraints on the lens-host system, and encourage follow-up efforts to confirm or rule out any viable lens. If this is indeed a lensed event, successfully pinpointing the system would offer a unique opportunity to identify the host galaxy of a BBH merger, and even localize the source within it. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.12709v1-abstract-full').style.display = 'none'; document.getElementById('2007.12709v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages including references, 8 figures, and one table</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.02155">arXiv:2007.02155</a> <span> [<a href="https://arxiv.org/pdf/2007.02155">pdf</a>, <a href="https://arxiv.org/format/2007.02155">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/aba4ac">10.3847/1538-4357/aba4ac <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Distant Fast Radio Burst Associated to its Host Galaxy with the Very Large Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Law%2C+C+J">C. J. Law</a>, <a href="/search/astro-ph?searchtype=author&query=Butler%2C+B+J">B. J. Butler</a>, <a href="/search/astro-ph?searchtype=author&query=Prochaska%2C+J+X">J. X. Prochaska</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">B. Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Burke-Spolaor%2C+S">S. Burke-Spolaor</a>, <a href="/search/astro-ph?searchtype=author&query=Mannings%2C+A">A. Mannings</a>, <a href="/search/astro-ph?searchtype=author&query=Tejos%2C+N">N. Tejos</a>, <a href="/search/astro-ph?searchtype=author&query=Josephy%2C+A">A. Josephy</a>, <a href="/search/astro-ph?searchtype=author&query=Andersen%2C+B">B. Andersen</a>, <a href="/search/astro-ph?searchtype=author&query=Chawla%2C+P">P. Chawla</a>, <a href="/search/astro-ph?searchtype=author&query=Heintz%2C+K+E">K. E. Heintz</a>, <a href="/search/astro-ph?searchtype=author&query=Aggarwal%2C+K">K. Aggarwal</a>, <a href="/search/astro-ph?searchtype=author&query=Bower%2C+G+C">G. C. Bower</a>, <a href="/search/astro-ph?searchtype=author&query=Demorest%2C+P+B">P. B. Demorest</a>, <a href="/search/astro-ph?searchtype=author&query=Kilpatrick%2C+C+D">C. D. Kilpatrick</a>, <a href="/search/astro-ph?searchtype=author&query=Lazio%2C+T+J+W">T. J. W. Lazio</a>, <a href="/search/astro-ph?searchtype=author&query=Linford%2C+J">J. Linford</a>, <a href="/search/astro-ph?searchtype=author&query=Mckinven%2C+R">R. Mckinven</a>, <a href="/search/astro-ph?searchtype=author&query=Tendulkar%2C+S">S. Tendulkar</a>, <a href="/search/astro-ph?searchtype=author&query=Simha%2C+S">S. Simha</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2007.02155v1-abstract-short" style="display: inline;"> We present the discovery and subarcsecond localization of a new Fast Radio Burst with the Karl G. Jansky Very Large Array and realfast search system. The FRB was discovered on 2019 June 14 with a dispersion measure of 959 pc/cm3. This is the highest DM of any localized FRB and its measured burst fluence of 0.6 Jy ms is less than nearly all other FRBs. The source is not detected to repeat in 15 hou… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.02155v1-abstract-full').style.display = 'inline'; document.getElementById('2007.02155v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.02155v1-abstract-full" style="display: none;"> We present the discovery and subarcsecond localization of a new Fast Radio Burst with the Karl G. Jansky Very Large Array and realfast search system. The FRB was discovered on 2019 June 14 with a dispersion measure of 959 pc/cm3. This is the highest DM of any localized FRB and its measured burst fluence of 0.6 Jy ms is less than nearly all other FRBs. The source is not detected to repeat in 15 hours of VLA observing and 153 hours of CHIME/FRB observing. We describe a suite of statistical and data quality tests we used to verify the significance of the event and its localization precision. Follow-up optical/infrared photometry with Keck and Gemini associate the FRB to a pair of galaxies with $\rm{r}\sim23$ mag. The false-alarm rate for radio transients of this significance that are associated with a host galaxy is roughly $3\times10^{-4}\ \rm{hr}^{-1}$. The two putative host galaxies have similar photometric redshifts of $z_{\rm{phot}}\sim0.6$, but different colors and stellar masses. Comparing the host distance to that implied by the dispersion measure suggests a modest (~ 50 pc/cm3) electron column density associated with the FRB environment or host galaxy/galaxies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.02155v1-abstract-full').style.display = 'none'; document.getElementById('2007.02155v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to AAS Journals (ApJ) and revised for referee comments</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.04513">arXiv:2003.04513</a> <span> [<a href="https://arxiv.org/pdf/2003.04513">pdf</a>, <a href="https://arxiv.org/format/2003.04513">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.102.103024">10.1103/PhysRevD.102.103024 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Source properties of the lowest signal-to-noise-ratio binary black hole detections </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y">Yiwen Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Haster%2C+C">Carl-Johan Haster</a>, <a href="/search/astro-ph?searchtype=author&query=Vitale%2C+S">Salvatore Vitale</a>, <a href="/search/astro-ph?searchtype=author&query=Zimmerman%2C+A">Aaron Zimmerman</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.04513v1-abstract-short" style="display: inline;"> We perform a detailed parameter estimation study of binary black hole merger events reported in Zackay et al. and Venumadhav et al.. These are some of the faintest signals reported so far, and hence, relative to the loud events in the GWTC-1 catalog, the data should have lesser constraining power on their intrinsic parameters. Hence we examine the robustness of parameter inference to choices made… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.04513v1-abstract-full').style.display = 'inline'; document.getElementById('2003.04513v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.04513v1-abstract-full" style="display: none;"> We perform a detailed parameter estimation study of binary black hole merger events reported in Zackay et al. and Venumadhav et al.. These are some of the faintest signals reported so far, and hence, relative to the loud events in the GWTC-1 catalog, the data should have lesser constraining power on their intrinsic parameters. Hence we examine the robustness of parameter inference to choices made in the analysis, as well as any potential systematics. We check the impact of different methods of estimating the noise power spectral density, different waveform models, and different priors for the compact object spins. For most of the events, the resulting differences in the inferred values of the parameters are much smaller than their statistical uncertainties. The estimation of the effective spin parameter $蠂_{\mathrm{eff}}$, i.e. the projection of the mass-weighted total spin along the angular momentum, can be sensitive to analysis choices for two of the sources with the largest effective spin magnitudes, GW151216 and GW170403. The primary differences arise from using a 3D isotropic spin prior: the tails of the posterior distributions should be interpreted with care and due consideration of the other data analysis choices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.04513v1-abstract-full').style.display = 'none'; document.getElementById('2003.04513v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LIGO P2000082 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1910.09528">arXiv:1910.09528</a> <span> [<a href="https://arxiv.org/pdf/1910.09528">pdf</a>, <a href="https://arxiv.org/format/1910.09528">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.104.063030">10.1103/PhysRevD.104.063030 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detecting Gravitational Waves With Disparate Detector Responses: Two New Binary Black Hole Mergers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1910.09528v1-abstract-short" style="display: inline;"> We introduce a new technique to search for gravitational wave events from compact binary mergers that produce a clear signal only in a single gravitational wave detector, and marginal signals in other detectors. Such a situation can arise when the detectors in a network have different sensitivities, or when sources have unfavorable sky locations or orientations. We start with a short list of loud… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.09528v1-abstract-full').style.display = 'inline'; document.getElementById('1910.09528v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.09528v1-abstract-full" style="display: none;"> We introduce a new technique to search for gravitational wave events from compact binary mergers that produce a clear signal only in a single gravitational wave detector, and marginal signals in other detectors. Such a situation can arise when the detectors in a network have different sensitivities, or when sources have unfavorable sky locations or orientations. We start with a short list of loud single-detector triggers from regions of parameter space that are empirically unaffected by glitches (after applying signal-quality vetoes). For each of these triggers, we compute evidence for astrophysical origin from the rest of the detector network by coherently combining the likelihoods from all detectors and marginalizing over extrinsic geometric parameters. We report the discovery of two new binary black hole (BBH) mergers in the second observing run of Advanced LIGO and Virgo (O2), in addition to the ones that were reported in Abbott et al. (2018) and Venumadhav et al. (2019). We estimate that the two events have false alarm rates of one in 19 years (60 O2) and one in 11 years (36 O2). One of the events, GW170817A, has primary and secondary masses $m_1^{\rm src} = 56_{-10}^{+16} \, M_\odot$ and $m_2^{\rm src} = 40_{-11}^{+10} \, M_\odot$ in the source frame. The existence of GW170817A should be very informative about the theoretically predicted upper mass gap for stellar mass black holes. Its effective spin parameter is measured to be $蠂_{\rm eff} = 0.5 \pm 0.2$, which is consistent with the tendency of the heavier detected BBH systems to have large and positive effective spin parameters. The other event, GWC170402, will be discussed thoroughly in future work. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.09528v1-abstract-full').style.display = 'none'; document.getElementById('1910.09528v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments are welcome</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 104, 063030 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1908.05644">arXiv:1908.05644</a> <span> [<a href="https://arxiv.org/pdf/1908.05644">pdf</a>, <a href="https://arxiv.org/format/1908.05644">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.104.063034">10.1103/PhysRevD.104.063034 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detecting Gravitational Waves in Data with Non-Gaussian Noise </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1908.05644v1-abstract-short" style="display: inline;"> Searches for gravitational waves crucially depend on exact signal processing of noisy strain data from gravitational wave detectors, which are known to exhibit significant non-Gaussian behavior. In this paper, we study two distinct non-Gaussian effects in the LIGO/Virgo data which reduce the sensitivity of searches: first, variations in the noise power spectral density (PSD) on timescales of more… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1908.05644v1-abstract-full').style.display = 'inline'; document.getElementById('1908.05644v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1908.05644v1-abstract-full" style="display: none;"> Searches for gravitational waves crucially depend on exact signal processing of noisy strain data from gravitational wave detectors, which are known to exhibit significant non-Gaussian behavior. In this paper, we study two distinct non-Gaussian effects in the LIGO/Virgo data which reduce the sensitivity of searches: first, variations in the noise power spectral density (PSD) on timescales of more than a few seconds; and second, loud and abrupt transient `glitches' of terrestrial or instrumental origin. We derive a simple procedure to correct, at first order, the effect of the variation in the PSD on the search background. Given the knowledge of the existence of localized glitches in particular segments of data, we also develop a method to insulate statistical inference from these glitches, so as to cleanly excise them without affecting the search background in neighboring seconds. We show the importance of applying these methods on the publicly available LIGO data, and measure an increase in the detection volume of at least $15\%$ from the PSD-drift correction alone, due to the improved background distribution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1908.05644v1-abstract-full').style.display = 'none'; document.getElementById('1908.05644v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">comments welcome</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 104, 063034 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.11252">arXiv:1907.11252</a> <span> [<a href="https://arxiv.org/pdf/1907.11252">pdf</a>, <a href="https://arxiv.org/format/1907.11252">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> SN 2018fif: The Explosion of a Large Red Supergiant Discovered in Its Infancy by the Zwicky Transient Facility </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Soumagnac%2C+M+T">Maayane T. Soumagnac</a>, <a href="/search/astro-ph?searchtype=author&query=Ganot%2C+N">Noam Ganot</a>, <a href="/search/astro-ph?searchtype=author&query=Irani%2C+I">Ido Irani</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-yam%2C+A">Avishay Gal-yam</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Waxman%2C+E">Eli Waxman</a>, <a href="/search/astro-ph?searchtype=author&query=Morag%2C+J">Jonathan Morag</a>, <a href="/search/astro-ph?searchtype=author&query=Yaron%2C+O">Ofer Yaron</a>, <a href="/search/astro-ph?searchtype=author&query=Schulze%2C+S">Steve Schulze</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yi Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Rubin%2C+A">Adam Rubin</a>, <a href="/search/astro-ph?searchtype=author&query=Cenko%2C+S+B">S. Bradley Cenko</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">Jesper Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Perley%2C+D+A">Daniel A. Perley</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">Christoffer Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Nugent%2C+P">Peter Nugent</a>, <a href="/search/astro-ph?searchtype=author&query=Neill%2C+J+D">James D. Neill</a>, <a href="/search/astro-ph?searchtype=author&query=Karamehmetoglu%2C+E">Emir Karamehmetoglu</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E+C">Eric C. Bellm</a>, <a href="/search/astro-ph?searchtype=author&query=Bruch%2C+R+J">Rachel J. Bruch</a>, <a href="/search/astro-ph?searchtype=author&query=Burruss%2C+R">Rick Burruss</a>, <a href="/search/astro-ph?searchtype=author&query=Cunningham%2C+V">Virginia Cunningham</a>, <a href="/search/astro-ph?searchtype=author&query=Dekany%2C+R">Richard Dekany</a>, <a href="/search/astro-ph?searchtype=author&query=Golkhou%2C+V+Z">V. Zach Golkhou</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">Mansi M. Kasliwal</a> , et al. (10 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.11252v2-abstract-short" style="display: inline;"> High cadence transient surveys are able to capture supernovae closer to their first light than before. Applying analytical models to such early emission, we can constrain the progenitor stars properties. In this paper, we present observations of SN2018fif (ZTF18abokyfk). The supernova was discovered close to first light and monitored by the Zwicky Transient Facility (ZTF) and the Neil Gehrels Swif… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.11252v2-abstract-full').style.display = 'inline'; document.getElementById('1907.11252v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.11252v2-abstract-full" style="display: none;"> High cadence transient surveys are able to capture supernovae closer to their first light than before. Applying analytical models to such early emission, we can constrain the progenitor stars properties. In this paper, we present observations of SN2018fif (ZTF18abokyfk). The supernova was discovered close to first light and monitored by the Zwicky Transient Facility (ZTF) and the Neil Gehrels Swift Observatory. Early spectroscopic observations suggest that the progenitor of SN2018fif was surrounded by relatively small amounts of circumstellar material (CSM) compared to all previous cases. This particularity, coupled with the high cadence multiple-band coverage, makes it a good candidate to investigate using shock-cooling models. We employ the SOPRANOS code, an implementation of the model by Sapir & Waxman and its extension to early times by Morag, Sapir & Waxman. Compared with previous implementations, SOPRANOS has the advantage of including a careful account of the limited temporal validity domain of the shock-cooling model as well as allowing usage of the entirety of the early UV data. We find that the progenitor of SN2018fif was a large red supergiant, with a radius of R=744.0_{-128.0}^{+183.0} solar radii and an ejected mass of Mej=9.3_{-5.8}^{+0.4} solar masses. Our model also gives information on the explosion epoch, the progenitor inner structure, the shock velocity and the extinction. The distribution of radii is double-peaked, with lower radii corresponding to lower values of the extinction, earlier recombination times and better match to the early UV data. If these correlations persist in future objects, denser spectroscopic monitoring constraining the time of recombination, as well as accurate UV observations (e.g. with ULTRASAT), will help break the radius-extinction degeneracy and independently determine both. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.11252v2-abstract-full').style.display = 'none'; document.getElementById('1907.11252v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.07214">arXiv:1904.07214</a> <span> [<a href="https://arxiv.org/pdf/1904.07214">pdf</a>, <a href="https://arxiv.org/format/1904.07214">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.101.083030">10.1103/PhysRevD.101.083030 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New binary black hole mergers in the second observing run of Advanced LIGO and Advanced Virgo </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1904.07214v2-abstract-short" style="display: inline;"> We report the detection of new binary black hole merger events in the publicly available data from the second observing run of advanced LIGO and advanced Virgo (O2). The mergers were discovered using the new search pipeline described in Venumadhav et al. [Phys. Rev. D 100, 023011 (2019)], and are above the detection thresholds as defined in Abbott et al. (LIGO Scientific and Virgo Collaborations)… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.07214v2-abstract-full').style.display = 'inline'; document.getElementById('1904.07214v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.07214v2-abstract-full" style="display: none;"> We report the detection of new binary black hole merger events in the publicly available data from the second observing run of advanced LIGO and advanced Virgo (O2). The mergers were discovered using the new search pipeline described in Venumadhav et al. [Phys. Rev. D 100, 023011 (2019)], and are above the detection thresholds as defined in Abbott et al. (LIGO Scientific and Virgo Collaborations) [Phys. Rev. X 9, 031040 (2019).] Three of the mergers (GW170121, GW170304, GW170727) have inferred probabilities of being of astrophysical origin $p_{\rm astro} > 0.98$. The remaining three (GW170425, GW170202, GW170403) are less certain, with $p_{\rm astro}$ ranging from 0.5 to 0.8. The newly found mergers largely share the statistical properties of previously reported events, with the exception of GW170403, the least secure event, which has a highly negative effective spin parameter $蠂_{\rm eff}$ . The most secure new event, GW170121 ($p_{\rm astro} > 0.99$), is also notable due to its inferred negative value of $蠂_{\rm eff}$, which is inconsistent with being positive at the ~95.8% confidence level. The new mergers nearly double the sample of gravitational wave events reported from O2, and present a substantial opportunity to explore the statistics of the binary black hole population in the Universe. The number of detected events is not surprising since we estimate that the detection volume of our pipeline may be larger than that of other pipelines by as much as a factor of two (with significant uncertainties in the estimate). The increase in volume is larger when the constituent detectors of the network have very different sensitivities, as is likely to be the case in current and future runs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.07214v2-abstract-full').style.display = 'none'; document.getElementById('1904.07214v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to PRD</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 101, 083030 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.01683">arXiv:1904.01683</a> <span> [<a href="https://arxiv.org/pdf/1904.01683">pdf</a>, <a href="https://arxiv.org/format/1904.01683">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.99.123022">10.1103/PhysRevD.99.123022 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Template Bank for Compact Binary Coalescence Searches in Gravitational Wave Data: A General Geometric Placement Algorithm </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1904.01683v2-abstract-short" style="display: inline;"> We introduce an algorithm for placing template waveforms for the search of compact binary mergers in gravitational wave interferometer data. We exploit the smooth dependence of the amplitude and unwrapped phase of the frequency-domain waveform on the parameters of the binary. We group waveforms with similar amplitude profiles and perform a singular value decomposition of the phase profiles to obta… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01683v2-abstract-full').style.display = 'inline'; document.getElementById('1904.01683v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.01683v2-abstract-full" style="display: none;"> We introduce an algorithm for placing template waveforms for the search of compact binary mergers in gravitational wave interferometer data. We exploit the smooth dependence of the amplitude and unwrapped phase of the frequency-domain waveform on the parameters of the binary. We group waveforms with similar amplitude profiles and perform a singular value decomposition of the phase profiles to obtain an orthonormal basis for the phase functions. The leading basis functions span a lower-dimensional linear space in which the unwrapped phase of any physical waveform is well approximated. The optimal template placement is given by a regular grid in the space of linear coefficients. The algorithm is applicable to any frequency-domain waveform model and detector sensitivity curve. It is computationally efficient and requires little tuning. Applying this method, we construct a set of template banks suitable for the search of aligned-spin binary neutron star, neutron-star--black-hole and binary black hole mergers in LIGO--Virgo data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01683v2-abstract-full').style.display = 'none'; document.getElementById('1904.01683v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 5 figures, 1 table. v2 matches the published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 99, 123022 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1903.04978">arXiv:1903.04978</a> <span> [<a href="https://arxiv.org/pdf/1903.04978">pdf</a>, <a href="https://arxiv.org/format/1903.04978">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Gravitational-wave-moderated Accretion: The Case of ES Ceti </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Coleman%2C+M+S+B">Matthew S. B. Coleman</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1903.04978v1-abstract-short" style="display: inline;"> We show that recent observations of the compact binary, AM CVn type system, ES Ceti are fully consistent with theoretical predictions of stable mass transfer moderated by angular momentum loss due to gravitational-wave radiation. One of the main predictions of this model (for degenerate donors) is a widening of the binary. The mass transfer rate inferred from the observed rate of change in the orb… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.04978v1-abstract-full').style.display = 'inline'; document.getElementById('1903.04978v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.04978v1-abstract-full" style="display: none;"> We show that recent observations of the compact binary, AM CVn type system, ES Ceti are fully consistent with theoretical predictions of stable mass transfer moderated by angular momentum loss due to gravitational-wave radiation. One of the main predictions of this model (for degenerate donors) is a widening of the binary. The mass transfer rate inferred from the observed rate of change in the orbital frequency is consistent with that inferred from the observed flux using the recent Gaia DR2 parallax <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.04978v1-abstract-full').style.display = 'none'; document.getElementById('1903.04978v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 2 figures, submitted to MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1903.02016">arXiv:1903.02016</a> <span> [<a href="https://arxiv.org/pdf/1903.02016">pdf</a>, <a href="https://arxiv.org/ps/1903.02016">ps</a>, <a href="https://arxiv.org/format/1903.02016">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1538-3873/ab0a19">10.1088/1538-3873/ab0a19 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A six year image-subtraction light curve of SN 2010jl </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">E. O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">B. Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">A. Gal-Yam</a>, <a href="/search/astro-ph?searchtype=author&query=Sollerman%2C+J">J. Sollerman</a>, <a href="/search/astro-ph?searchtype=author&query=Fransson%2C+C">C. Fransson</a>, <a href="/search/astro-ph?searchtype=author&query=Fremling%2C+C">C. Fremling</a>, <a href="/search/astro-ph?searchtype=author&query=Kulkarni%2C+S+R">S. R. Kulkarni</a>, <a href="/search/astro-ph?searchtype=author&query=Nugent%2C+P+E">P. E. Nugent</a>, <a href="/search/astro-ph?searchtype=author&query=Yaron%2C+O">O. Yaron</a>, <a href="/search/astro-ph?searchtype=author&query=Kasliwal%2C+M+M">M. M. Kasliwal</a>, <a href="/search/astro-ph?searchtype=author&query=Masci%2C+F">F. Masci</a>, <a href="/search/astro-ph?searchtype=author&query=Laher%2C+R">R. Laher</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1903.02016v1-abstract-short" style="display: inline;"> SN2010jl was a luminous Type IIn supernova (SN), detected in radio, optical, X-ray and hard X-rays. Here we report on its six year R- and g-band light curves obtained using the Palomar Transient Factory. The light curve was generated using a pipeline based on the proper image subtraction method and we discuss the algorithm performances. As noted before, the R-band light curve, up to about 300 days… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.02016v1-abstract-full').style.display = 'inline'; document.getElementById('1903.02016v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.02016v1-abstract-full" style="display: none;"> SN2010jl was a luminous Type IIn supernova (SN), detected in radio, optical, X-ray and hard X-rays. Here we report on its six year R- and g-band light curves obtained using the Palomar Transient Factory. The light curve was generated using a pipeline based on the proper image subtraction method and we discuss the algorithm performances. As noted before, the R-band light curve, up to about 300 days after maximum light is well described by a power-law decline with a power-law index of about -0.5. Between day 300 and day 2300 after maximum light, it is consistent with a power-law decline, with a power-law index of about -3.4. The longevity of the light curve suggests that the massive circum-stellar material around the progenitor was ejected on time scales of at least tens of years prior to the progenitor explosion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.02016v1-abstract-full').style.display = 'none'; document.getElementById('1903.02016v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, PASP in press</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1902.10341">arXiv:1902.10341</a> <span> [<a href="https://arxiv.org/pdf/1902.10341">pdf</a>, <a href="https://arxiv.org/format/1902.10341">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.100.023011">10.1103/PhysRevD.100.023011 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A New Search Pipeline for Compact Binary Mergers: Results for Binary Black Holes in the First Observing Run of Advanced LIGO </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1902.10341v2-abstract-short" style="display: inline;"> In this paper, we report on the construction of a new and independent pipeline for analyzing the public data from the first observing run of advanced LIGO for mergers of compact binary systems. The pipeline incorporates different techniques and makes independent implementation choices in all its stages including the search design, the method to construct template banks, the automatic routines to d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.10341v2-abstract-full').style.display = 'inline'; document.getElementById('1902.10341v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.10341v2-abstract-full" style="display: none;"> In this paper, we report on the construction of a new and independent pipeline for analyzing the public data from the first observing run of advanced LIGO for mergers of compact binary systems. The pipeline incorporates different techniques and makes independent implementation choices in all its stages including the search design, the method to construct template banks, the automatic routines to detect bad data segments ("glitches") and to insulate good data from them, the procedure to account for the non-stationary nature of the detector noise, the signal-quality vetoes at the single-detector level and the methods to combine results from multiple detectors. Our pipeline enabled us to identify a new binary black-hole merger GW151216 in the public LIGO data. This paper serves as a bird's eye view of the pipeline's important stages. Full details and derivations underlying the various stages will appear in accompanying papers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.10341v2-abstract-full').style.display = 'none'; document.getElementById('1902.10341v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments are welcome!</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 100, 023011 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1902.10331">arXiv:1902.10331</a> <span> [<a href="https://arxiv.org/pdf/1902.10331">pdf</a>, <a href="https://arxiv.org/format/1902.10331">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.100.023007">10.1103/PhysRevD.100.023007 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Highly Spinning and Aligned Binary Black Hole Merger in the Advanced LIGO First Observing Run </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Roulet%2C+J">Javier Roulet</a>, <a href="/search/astro-ph?searchtype=author&query=Zaldarriaga%2C+M">Matias Zaldarriaga</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1902.10331v2-abstract-short" style="display: inline;"> We report a new binary black hole merger in the publicly available LIGO First Observing Run (O1) data release. The event has an inverse false alarm rate of one per six years in the detector-frame chirp-mass range $\mathcal{M}^{\rm det} \in [20,40]M_\odot$ in a new independent analysis pipeline that we developed. Our best estimate of the probability that the event is of astrophysical origin is… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.10331v2-abstract-full').style.display = 'inline'; document.getElementById('1902.10331v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.10331v2-abstract-full" style="display: none;"> We report a new binary black hole merger in the publicly available LIGO First Observing Run (O1) data release. The event has an inverse false alarm rate of one per six years in the detector-frame chirp-mass range $\mathcal{M}^{\rm det} \in [20,40]M_\odot$ in a new independent analysis pipeline that we developed. Our best estimate of the probability that the event is of astrophysical origin is $P_{\rm astro} \sim 0.71\, .$ The estimated physical parameters of the event indicate that it is the merger of two massive black holes, $\mathcal{M}^{\rm det} = 31^{+2}_{-3}\,M_\odot$ with an effective spin parameter, $蠂_{\rm eff} = 0.81^{+0.15}_{-0.21}$, making this the most highly spinning merger reported to date. It is also among the two highest redshift mergers observed so far. The high aligned spin of the merger supports the hypothesis that merging binary black holes can be created by binary stellar evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.10331v2-abstract-full').style.display = 'none'; document.getElementById('1902.10331v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments are welcome. To be submitted to a journal soon</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 100, 023007 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1810.00003">arXiv:1810.00003</a> <span> [<a href="https://arxiv.org/pdf/1810.00003">pdf</a>, <a href="https://arxiv.org/format/1810.00003">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevD.98.104029">10.1103/PhysRevD.98.104029 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detecting Lensing-Induced Diffraction in Astrophysical Gravitational Waves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+S">Shun-Sheng Li</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Mao%2C+S">Shude Mao</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+Y">Youjun Lu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1810.00003v1-abstract-short" style="display: inline;"> Gravitational waves emitted from compact binary coalescence can be subject to wave diffraction if they are gravitationally lensed by an intervening mass clump whose Schwarzschild timescale matches the wave period. Waves in the ground-based frequency band $f\sim 10$--$10^3\,$Hz are sensitive to clumps with masses $M_E \sim 10^2$--$10^3\,M_\odot$ enclosed within the impact parameter. These can be th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.00003v1-abstract-full').style.display = 'inline'; document.getElementById('1810.00003v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.00003v1-abstract-full" style="display: none;"> Gravitational waves emitted from compact binary coalescence can be subject to wave diffraction if they are gravitationally lensed by an intervening mass clump whose Schwarzschild timescale matches the wave period. Waves in the ground-based frequency band $f\sim 10$--$10^3\,$Hz are sensitive to clumps with masses $M_E \sim 10^2$--$10^3\,M_\odot$ enclosed within the impact parameter. These can be the central parts of low mass $M_L \sim 10^3$--$10^6\,M_\odot$ dark matter halos, which are predicted in Cold Dark Matter scenarios but are challenging to observe. Neglecting finely-tuned impact parameters, we focus on lenses aligned generally on the Einstein scale for which multiple lensed images may not form in the case of an extended lens. In this case, diffraction induces amplitude and phase modulations whose sizes $\sim 10\%$--$20\%$ are small enough so that standard matched filtering with unlensed waveforms do not degrade, but are still detectable for events with high signal-to-noise ratio. We develop and test an agnostic detection method based on dynamic programming, which does not require a detailed model of the lensed waveforms. For pseudo-Jaffe lenses aligned up to the Einstein radius, we demonstrate that a pair of fully upgraded aLIGO/Virgo detectors can extract diffraction imprints from binary black hole mergers out to $z_s \sim 0.2$--$0.3$. The prospect will improve dramatically for a third-generation detector for which binary black hole mergers out to $z_s \sim 2$--$4$ will all become valuable sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.00003v1-abstract-full').style.display = 'none'; document.getElementById('1810.00003v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages including references; 8 figures; comments are welcome</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 98, 104029 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1809.09933">arXiv:1809.09933</a> <span> [<a href="https://arxiv.org/pdf/1809.09933">pdf</a>, <a href="https://arxiv.org/format/1809.09933">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/ab27c7">10.3847/1538-3881/ab27c7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A possible advantage of telescopes with a non-circular pupil </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">Guy Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1809.09933v1-abstract-short" style="display: inline;"> Most telescope designs have a circular-shape aperture. We demonstrate that telescopes with an elongated pupil have better contrast, at lower separations, between a bright central star and a faint companion. We simulate images for an elongated-pupil telescope and for a circular-pupil telescope of equal aperture area and integration time, investigating specifically what is the maximal contrast for f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.09933v1-abstract-full').style.display = 'inline'; document.getElementById('1809.09933v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.09933v1-abstract-full" style="display: none;"> Most telescope designs have a circular-shape aperture. We demonstrate that telescopes with an elongated pupil have better contrast, at lower separations, between a bright central star and a faint companion. We simulate images for an elongated-pupil telescope and for a circular-pupil telescope of equal aperture area and integration time, investigating specifically what is the maximal contrast for finding faint companions around bright stars as a function of angular separation. We show that this design gives better contrast at lower separation from a bright star. This is shown for diffraction-limited (for perfect and imperfect optics) and seeing-limited speckle images, assuming equal aperture area and observing time. We also show the results are robust to errors in measurement of the point spread function. To compensate for the wider point spread function of the short axis, images should be taken at different rotation angles, either by rotating the telescope around the optical axis or by allowing a stationary mirror array to scan different parallactic angles with time. Images taken at different rotation angles are added using the proper image coaddition algorithms developed by Zackay & Ofek. The final image has the same contrast in all angles, rather than in specific areas of diffraction nulls. We obtained speckle observations with a small, ground based elongated-aperture telescope and show the results are consistent with simulations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.09933v1-abstract-full').style.display = 'none'; document.getElementById('1809.09933v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1806.08793">arXiv:1806.08793</a> <span> [<a href="https://arxiv.org/pdf/1806.08793">pdf</a>, <a href="https://arxiv.org/format/1806.08793">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Parameter Estimation for GW170817 using Relative Binning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1806.08793v2-abstract-short" style="display: inline;"> Relative binning is a new method for fast and accurate evaluation of the likelihood of gravitational wave strain data. This technique can be used to produce reliable posterior distributions for compact object mergers with very moderate computational resources. We use a fast likelihood evaluation code based on this technique to estimate the parameters of the double neutron-star merger event GW17081… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.08793v2-abstract-full').style.display = 'inline'; document.getElementById('1806.08793v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1806.08793v2-abstract-full" style="display: none;"> Relative binning is a new method for fast and accurate evaluation of the likelihood of gravitational wave strain data. This technique can be used to produce reliable posterior distributions for compact object mergers with very moderate computational resources. We use a fast likelihood evaluation code based on this technique to estimate the parameters of the double neutron-star merger event GW170817 using publicly available LIGO data. We obtain statistically similar posteriors using either Markov-chain Monte-Carlo or nested sampling. The results do not favor non-zero aligned spins at a statistically significant level. There is no significant sign of non-zero tidal deformability (as quantified by the Bayesian evidence), whether or not high-spin or low-spin priors are adopted. Our posterior samples are publicly available, and we also provide a tutorial Python code to implement fast likelihood evaluation using the relative binning method. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.08793v2-abstract-full').style.display = 'none'; document.getElementById('1806.08793v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 1 table, 5 figures. In version 2 we added a comparison between two difference choices for the high frequency cutoff (1000 Hz versus 1500 Hz). The relative binning technique is presented in a companion paper arXiv:1806.08792. Reference python code and posterior samples are available to download at: https://bitbucket.org/dailiang8/gwbinning/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1806.08792">arXiv:1806.08792</a> <span> [<a href="https://arxiv.org/pdf/1806.08792">pdf</a>, <a href="https://arxiv.org/format/1806.08792">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> </div> <p class="title is-5 mathjax"> Relative Binning and Fast Likelihood Evaluation for Gravitational Wave Parameter Estimation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Liang Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Venumadhav%2C+T">Tejaswi Venumadhav</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1806.08792v2-abstract-short" style="display: inline;"> We present a method to accelerate the evaluation of the likelihood in gravitational wave parameter estimation. Parameter estimation codes compute likelihoods of similar waveforms, whose phases and amplitudes differ smoothly with frequency. We exploit this by precomputing frequency-binned overlaps of the best-fit waveform with the data. We show how these summary data can be used to approximate the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.08792v2-abstract-full').style.display = 'inline'; document.getElementById('1806.08792v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1806.08792v2-abstract-full" style="display: none;"> We present a method to accelerate the evaluation of the likelihood in gravitational wave parameter estimation. Parameter estimation codes compute likelihoods of similar waveforms, whose phases and amplitudes differ smoothly with frequency. We exploit this by precomputing frequency-binned overlaps of the best-fit waveform with the data. We show how these summary data can be used to approximate the likelihood of any waveform that is sufficiently probable within the required accuracy. We demonstrate that $\simeq 60$ bins suffice to accurately compute likelihoods for strain data at a sampling rate of $4096\,$Hz and duration of $T=2048\,$s around the binary neutron star merger GW170817. Relative binning speeds up parameter estimation for frequency domain waveform models by a factor of $\sim 10^4$ compared to naive matched filtering and $\sim 10$ compared to reduced order quadrature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.08792v2-abstract-full').style.display = 'none'; document.getElementById('1806.08792v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 2 figures, 1 table. Application of Relative Binning to GW170817 is presented in a companion paper arXiv 1806.08793 . Comments are welcome. Some references and acknowledgements added</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1806.04204">arXiv:1806.04204</a> <span> [<a href="https://arxiv.org/pdf/1806.04204">pdf</a>, <a href="https://arxiv.org/format/1806.04204">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/aaddff">10.3847/1538-3881/aaddff <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optimal and Efficient Streak Detection in Astronomical Images </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Nir%2C+G">Guy Nir</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1806.04204v2-abstract-short" style="display: inline;"> Identification of linear features (streaks) in astronomical images is important for several reasons, including: detecting fast-moving near-Earth asteroids; detecting or flagging faint satellites streaks; and flagging or removing diffraction spikes, pixel bleeding, line-like cosmic rays and bad-pixel features. Here we discuss an efficient and optimal algorithm for the detection of such streaks. The… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.04204v2-abstract-full').style.display = 'inline'; document.getElementById('1806.04204v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1806.04204v2-abstract-full" style="display: none;"> Identification of linear features (streaks) in astronomical images is important for several reasons, including: detecting fast-moving near-Earth asteroids; detecting or flagging faint satellites streaks; and flagging or removing diffraction spikes, pixel bleeding, line-like cosmic rays and bad-pixel features. Here we discuss an efficient and optimal algorithm for the detection of such streaks. The optimal method to detect streaks in astronomical images is by cross-correlating the image with a template of a line broadened by the point spread function of the system. To do so efficiently, the cross-correlation of the streak position and angle is performed using the Radon transform, which is the integral of pixel values along all possible lines through an image. A fast version of the Radon transform exists, which we here extend to efficiently detect arbitrarily short lines. While the brute force Radon transform requires an order of N^3 operations for an N by N image, the fast Radon transform has a complexity of the order of N^2 log(N). We apply this method to simulated images, recovering the theoretical signal-to-noise ratio, and to real images, finding long streaks of low-Earth-orbit satellites and shorter streaks of Global Positioning System satellites. We detect streaks that are barely visible to the eye, out of hundreds of images, without a-priori knowledge of the streaks' positions or angles. We provide implementation of this algorithm in Python and MATLAB. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.04204v2-abstract-full').style.display = 'none'; document.getElementById('1806.04204v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1709.01524">arXiv:1709.01524</a> <span> [<a href="https://arxiv.org/pdf/1709.01524">pdf</a>, <a href="https://arxiv.org/ps/1709.01524">ps</a>, <a href="https://arxiv.org/format/1709.01524">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/aab265">10.3847/1538-3881/aab265 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optimal matched filter in the low-number count Poisson noise regime and implications for X-ray source detection </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1709.01524v1-abstract-short" style="display: inline;"> Detection of templates (e.g., sources) embedded in low-number count Poisson noise is a common problem in astrophysics. Examples include source detection in X-ray images, gamma-rays, UV, neutrinos, and search for clusters of galaxies and stellar streams. However, the solutions in the X-ray-related literature are sub-optimal -- in some cases by considerable factors. Using the lemma of Neyman-Pearson… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1709.01524v1-abstract-full').style.display = 'inline'; document.getElementById('1709.01524v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1709.01524v1-abstract-full" style="display: none;"> Detection of templates (e.g., sources) embedded in low-number count Poisson noise is a common problem in astrophysics. Examples include source detection in X-ray images, gamma-rays, UV, neutrinos, and search for clusters of galaxies and stellar streams. However, the solutions in the X-ray-related literature are sub-optimal -- in some cases by considerable factors. Using the lemma of Neyman-Pearson we derive the optimal statistics for template detection in the presence of Poisson noise. We demonstrate that this method provides higher completeness, for a fixed false-alarm probability value, compared with filtering the image with the point-spread function (PSF). In turn, we find that filtering by the PSF is better than filtering the image using the Mexican-hat wavelet (used by wavedetect). For some background levels, our method improves the sensitivity of source detection by more than a factor of two over the popular Mexican-hat wavelet filtering. This filtering technique can also be used also for fast PSF photometry and flare detection, and it is efficient, as well as straight forward to implement. We provide an implementation in MATLAB. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1709.01524v1-abstract-full').style.display = 'none'; document.getElementById('1709.01524v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 September, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1705.07581">arXiv:1705.07581</a> <span> [<a href="https://arxiv.org/pdf/1705.07581">pdf</a>, <a href="https://arxiv.org/format/1705.07581">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/aa71ff">10.3847/2041-8213/aa71ff <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The detection of an extremely bright fast radio burst in a phased array feed survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bannister%2C+K">Keith Bannister</a>, <a href="/search/astro-ph?searchtype=author&query=Shannon%2C+R">Ryan Shannon</a>, <a href="/search/astro-ph?searchtype=author&query=Macquart%2C+J">Jean-Pierre Macquart</a>, <a href="/search/astro-ph?searchtype=author&query=Flynn%2C+C">Chris Flynn</a>, <a href="/search/astro-ph?searchtype=author&query=Edwards%2C+P">Philip Edwards</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Neill%2C+M">Morgan O'Neill</a>, <a href="/search/astro-ph?searchtype=author&query=Os%C5%82owski%2C+S">Stefan Os艂owski</a>, <a href="/search/astro-ph?searchtype=author&query=Bailes%2C+M">Matthew Bailes</a>, <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Clarke%2C+N">Nathan Clarke</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Addario%2C+L">Larry D'Addario</a>, <a href="/search/astro-ph?searchtype=author&query=Dodson%2C+R">Richard Dodson</a>, <a href="/search/astro-ph?searchtype=author&query=Hall%2C+P">Peter Hall</a>, <a href="/search/astro-ph?searchtype=author&query=Jameson%2C+A">Andrew Jameson</a>, <a href="/search/astro-ph?searchtype=author&query=Jones%2C+D">Dayton Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Navarro%2C+R">Robert Navarro</a>, <a href="/search/astro-ph?searchtype=author&query=Trinh%2C+J">Joseph Trinh</a>, <a href="/search/astro-ph?searchtype=author&query=Allison%2C+J">James Allison</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+C">Craig Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Bell%2C+M">Martin Bell</a>, <a href="/search/astro-ph?searchtype=author&query=Chippendale%2C+A">Aaron Chippendale</a>, <a href="/search/astro-ph?searchtype=author&query=Collier%2C+J">Jordan Collier</a>, <a href="/search/astro-ph?searchtype=author&query=Heald%2C+G">George Heald</a>, <a href="/search/astro-ph?searchtype=author&query=Heywood%2C+I">Ian Heywood</a>, <a href="/search/astro-ph?searchtype=author&query=Hotan%2C+A">Aidan Hotan</a> , et al. (31 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1705.07581v2-abstract-short" style="display: inline;"> We report the detection of an ultra-bright fast radio burst (FRB) from a modest, 3.4-day pilot survey with the Australian Square Kilometre Array Pathfinder. The survey was conducted in a wide-field fly's-eye configuration using the phased-array-feed technology deployed on the array to instantaneously observe an effective area of $160$ deg$^2$, and achieve an exposure totaling $13200$ deg$^2$ hr. W… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.07581v2-abstract-full').style.display = 'inline'; document.getElementById('1705.07581v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1705.07581v2-abstract-full" style="display: none;"> We report the detection of an ultra-bright fast radio burst (FRB) from a modest, 3.4-day pilot survey with the Australian Square Kilometre Array Pathfinder. The survey was conducted in a wide-field fly's-eye configuration using the phased-array-feed technology deployed on the array to instantaneously observe an effective area of $160$ deg$^2$, and achieve an exposure totaling $13200$ deg$^2$ hr. We constrain the position of FRB 170107 to a region $8'\times8'$ in size (90% containment) and its fluence to be $58\pm6$ Jy ms. The spectrum of the burst shows a sharp cutoff above $1400$ MHz, which could be either due to scintillation or an intrinsic feature of the burst. This confirms the existence of an ultra-bright ($>20$ Jy ms) population of FRBs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.07581v2-abstract-full').style.display = 'none'; document.getElementById('1705.07581v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 4 figures, accepted in ApJ letters. Version 2: Fixed galactic coordinates in Table 2</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1601.02655">arXiv:1601.02655</a> <span> [<a href="https://arxiv.org/pdf/1601.02655">pdf</a>, <a href="https://arxiv.org/format/1601.02655">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/0004-637X/830/1/27">10.3847/0004-637X/830/1/27 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Proper image subtraction - optimal transient detection, photometry and hypothesis testing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a>, <a href="/search/astro-ph?searchtype=author&query=Gal-Yam%2C+A">Avishay Gal-Yam</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1601.02655v2-abstract-short" style="display: inline;"> Transient detection and flux measurement via image subtraction stand at the base of time domain astronomy. Due to the varying seeing conditions, the image subtraction process is non-trivial, and existing solutions suffer from a variety of problems. Starting from basic statistical principles, we develop the optimal statistic for transient detection, flux measurement and any image-difference hypothe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.02655v2-abstract-full').style.display = 'inline'; document.getElementById('1601.02655v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1601.02655v2-abstract-full" style="display: none;"> Transient detection and flux measurement via image subtraction stand at the base of time domain astronomy. Due to the varying seeing conditions, the image subtraction process is non-trivial, and existing solutions suffer from a variety of problems. Starting from basic statistical principles, we develop the optimal statistic for transient detection, flux measurement and any image-difference hypothesis testing. We derive a closed-form statistic that: (i) Is mathematically proven to be the optimal transient detection statistic in the limit of background-dominated noise; (ii) Is numerically stable; (iii) For accurately registered, adequately sampled images, does not leave subtraction or deconvolution artifacts; (iv) Allows automatic transient detection to the theoretical sensitivity limit by providing credible detection significance; (v) Has uncorrelated white noise; (vi) Is a sufficient statistic for any further statistical test on the difference image, and in particular, allows to distinguish particle hits and other image artifacts from real transients; (vii) Is symmetric to the exchange of the new and reference images; (viii) Is at least an order of magnitude faster to compute than some popular methods; and (ix) Is straightforward to implement. Furthermore, we present extensions of this method that make it resilient to registration errors, color-refraction errors, and any noise source that can be modelled. In addition, we show that the optimal way to prepare a reference image is the proper image coaddition presented in Zackay \& Ofek (2015b). We demonstrate this method on simulated data and real observations from the Palomar Transient Factory data release 2. We provide an implementation of this algorithm in MATLAB and Python. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.02655v2-abstract-full').style.display = 'none'; document.getElementById('1601.02655v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 February, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 January, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments are welcome. Authors name corrected</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1512.06879">arXiv:1512.06879</a> <span> [<a href="https://arxiv.org/pdf/1512.06879">pdf</a>, <a href="https://arxiv.org/format/1512.06879">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/836/2/188">10.3847/1538-4357/836/2/188 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> How to coadd images? II. A coaddition image that is optimal for any purpose in the background dominated noise limit </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1512.06879v1-abstract-short" style="display: inline;"> Image coaddition is one of the most basic operations that astronomers perform. In Paper~I, we presented the optimal ways to coadd images in order to detect faint sources and to perfrom flux measurements under the assumption that the noise is approximately Gaussian. Here, we build on these results and derive from first principles a coaddition technique which is optimal for any hypothesis testing an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1512.06879v1-abstract-full').style.display = 'inline'; document.getElementById('1512.06879v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1512.06879v1-abstract-full" style="display: none;"> Image coaddition is one of the most basic operations that astronomers perform. In Paper~I, we presented the optimal ways to coadd images in order to detect faint sources and to perfrom flux measurements under the assumption that the noise is approximately Gaussian. Here, we build on these results and derive from first principles a coaddition technique which is optimal for any hypothesis testing and measurement (e.g., source detection, flux or shape measurements and star/galaxy separation), in the background-noise-dominated case. This method has several important properties. The pixels of the resulting coadd image are uncorrelated. This image preserves all the information (from the original individual images) on all spatial frequencies. Any hypothesis testing or measurement that can be done on all the individual images simultaneously, can be done on the coadded image without any loss of information. The PSF of this image is typically as narrow, or narrower than the PSF of the best image in the ensemble. Moreover, this image is practically indistinguishable from a regular single image, meaning that any code that measures any property on a regular astronomical image can be applied to it unchanged. In particular, the optimal source detection statistic derived in paper~I is reproduced by matched filtering this image with its own PSF. This coaddition process, which we call proper coaddition, can be understood as a the maximum signal-to-noise ratio measurement of the Fourier transform of the image, weighted in such a way that the noise in the entire Fourier domain is of equal variance. This method has important implications for multi-epoch seeing-limited deep surveys, weak lensing galaxy shape measurements, and diffraction-limited imaging via speckle observations. The last topic will be covered in depth in future papers. We provide an implementation of this algorithm in MATLAB. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1512.06879v1-abstract-full').style.display = 'none'; document.getElementById('1512.06879v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 December, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ Comments are welcome!</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1512.06872">arXiv:1512.06872</a> <span> [<a href="https://arxiv.org/pdf/1512.06872">pdf</a>, <a href="https://arxiv.org/format/1512.06872">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/836/2/187">10.3847/1538-4357/836/2/187 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> How to coadd images? I. Optimal source detection and photometry using ensembles of images </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1512.06872v1-abstract-short" style="display: inline;"> Stacks of digital astronomical images are combined in order to increase image depth. The variable seeing conditions, sky background and transparency of ground-based observations make the coaddition process non-trivial. We present image coaddition methods optimized for source detection and flux measurement, that maximize the signal-to-noise ratio (S/N). We show that for these purposes the best way… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1512.06872v1-abstract-full').style.display = 'inline'; document.getElementById('1512.06872v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1512.06872v1-abstract-full" style="display: none;"> Stacks of digital astronomical images are combined in order to increase image depth. The variable seeing conditions, sky background and transparency of ground-based observations make the coaddition process non-trivial. We present image coaddition methods optimized for source detection and flux measurement, that maximize the signal-to-noise ratio (S/N). We show that for these purposes the best way to combine images is to apply a matched filter to each image using its own point spread function (PSF) and only then to sum the images with the appropriate weights. Methods that either match filter after coaddition, or perform PSF homogenization prior to coaddition will result in loss of sensitivity. We argue that our method provides an increase of between a few and 25 percent in the survey speed of deep ground-based imaging surveys compared with weighted coaddition techniques. We demonstrate this claim using simulated data as well as data from the Palomar Transient Factory data release 2. We present a variant of this coaddition method which is optimal for PSF or aperture photometry. We also provide an analytic formula for calculating the S/N for PSF photometry on single or multiple observations. In the next paper in this series we present a method for image coaddition in the limit of background-dominated noise which is optimal for any statistical test or measurement on the constant-in-time image (e.g., source detection, shape or flux measurement or star-galaxy separation), making the original data redundant. We provide an implementation of this algorithm in MATLAB. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1512.06872v1-abstract-full').style.display = 'none'; document.getElementById('1512.06872v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 December, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ. Comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1411.5373">arXiv:1411.5373</a> <span> [<a href="https://arxiv.org/pdf/1411.5373">pdf</a>, <a href="https://arxiv.org/ps/1411.5373">ps</a>, <a href="https://arxiv.org/format/1411.5373">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/835/1/11">10.3847/1538-4357/835/1/11 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An accurate and efficient algorithm for detection of radio bursts with an unknown dispersion measure, for single dish telescopes and interferometers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zackay%2C+B">Barak Zackay</a>, <a href="/search/astro-ph?searchtype=author&query=Ofek%2C+E+O">Eran O. Ofek</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1411.5373v1-abstract-short" style="display: inline;"> Astronomical radio bursts disperse while traveling through the interstellar medium. To optimally detect a short-duration signal within a frequency band, we have to precisely compensate for the pulse dispersion, which is a computationally demanding task. We present the Fast Dispersion Measure Transform (FDMT) algorithm for optimal detection of such signals. Our algorithm has a low theoretical compl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1411.5373v1-abstract-full').style.display = 'inline'; document.getElementById('1411.5373v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1411.5373v1-abstract-full" style="display: none;"> Astronomical radio bursts disperse while traveling through the interstellar medium. To optimally detect a short-duration signal within a frequency band, we have to precisely compensate for the pulse dispersion, which is a computationally demanding task. We present the Fast Dispersion Measure Transform (FDMT) algorithm for optimal detection of such signals. Our algorithm has a low theoretical complexity of 2N_f N_t+ N_t N_d log_2(N_f) where N_f, N_t and N_d are the numbers of frequency bins, time bins, and dispersion measure bins, respectively. Unlike previously suggested fast algorithms our algorithm conserves the sensitivity of brute force dedispersion. Our tests indicate that this algorithm, running on a standard desktop computer, and implemented in a high-level programming language, is already faster than the state of the art dedispersion codes running on graphical processing units (GPUs). We also present a variant of the algorithm that can be efficiently implemented on GPUs. The latter algorithm's computation and data transport requirements are similar to those of two-dimensional FFT, indicating that incoherent dedispersion can now be considered a non-issue while planning future surveys. We further present a fast algorithm for sensitive dedispersion of pulses shorter than normally allowed by incoherent dedispersion. In typical cases this algorithm is orders of magnitude faster than coherent dedispersion by convolution. We analyze the computational complexity of pulsed signal searches by radio interferometers. We conclude that, using our suggested algorithms, maximally sensitive blind searches for such pulses is feasible using existing facilities. We provide an implementation of these algorithms in Python and MATLAB. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1411.5373v1-abstract-full').style.display = 'none'; document.getElementById('1411.5373v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 November, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to ApJ. Comments and suggestions are welcome!</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Zackay%2C+B&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Zackay%2C+B&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Zackay%2C+B&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> 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