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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <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/2302.05163">arXiv:2302.05163</a> <span> [<a href="https://arxiv.org/pdf/2302.05163">pdf</a>, <a href="https://arxiv.org/format/2302.05163">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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> </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/10.21105/astro.2302.05163">10.21105/astro.2302.05163 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> JAX-COSMO: An End-to-End Differentiable and GPU Accelerated Cosmology Library </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Lanusse%2C+F">Fran莽ois Lanusse</a>, <a href="/search/astro-ph?searchtype=author&query=Zuntz%2C+J">Joe Zuntz</a>, <a href="/search/astro-ph?searchtype=author&query=Boucaud%2C+A">Alexandre Boucaud</a>, <a href="/search/astro-ph?searchtype=author&query=Casas%2C+S">Santiago Casas</a>, <a href="/search/astro-ph?searchtype=author&query=Karamanis%2C+M">Minas Karamanis</a>, <a href="/search/astro-ph?searchtype=author&query=Kirkby%2C+D">David Kirkby</a>, <a href="/search/astro-ph?searchtype=author&query=Lanzieri%2C+D">Denise Lanzieri</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Y">Yin Li</a>, <a href="/search/astro-ph?searchtype=author&query=Peel%2C+A">Austin Peel</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="2302.05163v2-abstract-short" style="display: inline;"> We present jax-cosmo, a library for automatically differentiable cosmological theory calculations. It uses the JAX library, which has created a new coding ecosystem, especially in probabilistic programming. As well as batch acceleration, just-in-time compilation, and automatic optimization of code for different hardware modalities (CPU, GPU, TPU), JAX exposes an automatic differentiation (autodiff… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.05163v2-abstract-full').style.display = 'inline'; document.getElementById('2302.05163v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.05163v2-abstract-full" style="display: none;"> We present jax-cosmo, a library for automatically differentiable cosmological theory calculations. It uses the JAX library, which has created a new coding ecosystem, especially in probabilistic programming. As well as batch acceleration, just-in-time compilation, and automatic optimization of code for different hardware modalities (CPU, GPU, TPU), JAX exposes an automatic differentiation (autodiff) mechanism. Thanks to autodiff, jax-cosmo gives access to the derivatives of cosmological likelihoods with respect to any of their parameters, and thus enables a range of powerful Bayesian inference algorithms, otherwise impractical in cosmology, such as Hamiltonian Monte Carlo and Variational Inference. In its initial release, jax-cosmo implements background evolution, linear and non-linear power spectra (using halofit or the Eisenstein and Hu transfer function), as well as angular power spectra with the Limber approximation for galaxy and weak lensing probes, all differentiable with respect to the cosmological parameters and their other inputs. We illustrate how autodiff can be a game-changer for common tasks involving Fisher matrix computations, or full posterior inference with gradient-based techniques. In particular, we show how Fisher matrices are now fast, exact, no longer require any fine tuning, and are themselves differentiable. Finally, using a Dark Energy Survey Year 1 3x2pt analysis as a benchmark, we demonstrate how jax-cosmo can be combined with Probabilistic Programming Languages to perform posterior inference with state-of-the-art algorithms including a No U-Turn Sampler, Automatic Differentiation Variational Inference,and Neural Transport HMC. We further demonstrate that Normalizing Flows using Neural Transport are a promising methodology for model validation in the early stages of analysis. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.05163v2-abstract-full').style.display = 'none'; document.getElementById('2302.05163v2-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">v1</span> submitted 10 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.04291">arXiv:2212.04291</a> <span> [<a href="https://arxiv.org/pdf/2212.04291">pdf</a>, <a href="https://arxiv.org/format/2212.04291">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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/10.21105/astro.2212.04291">10.21105/astro.2212.04291 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The N5K Challenge: Non-Limber Integration for LSST Cosmology </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leonard%2C+C+D">C. D. Leonard</a>, <a href="/search/astro-ph?searchtype=author&query=Ferreira%2C+T">T. Ferreira</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+X">X. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Reischke%2C+R">R. Reischke</a>, <a href="/search/astro-ph?searchtype=author&query=Schoeneberg%2C+N">N. Schoeneberg</a>, <a href="/search/astro-ph?searchtype=author&query=Tr%C3%B6ster%2C+T">T. Tr枚ster</a>, <a href="/search/astro-ph?searchtype=author&query=Alonso%2C+D">D. Alonso</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Lanusse%2C+F">F. Lanusse</a>, <a href="/search/astro-ph?searchtype=author&query=Slosar%2C+A">A. Slosar</a>, <a href="/search/astro-ph?searchtype=author&query=Ishak%2C+M">M. Ishak</a>, <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+t+L+D+E+S">the LSST Dark Energy Science Collaboration</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="2212.04291v2-abstract-short" style="display: inline;"> The rapidly increasing statistical power of cosmological imaging surveys requires us to reassess the regime of validity for various approximations that accelerate the calculation of relevant theoretical predictions. In this paper, we present the results of the 'N5K non-Limber integration challenge', the goal of which was to quantify the performance of different approaches to calculating the angula… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.04291v2-abstract-full').style.display = 'inline'; document.getElementById('2212.04291v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.04291v2-abstract-full" style="display: none;"> The rapidly increasing statistical power of cosmological imaging surveys requires us to reassess the regime of validity for various approximations that accelerate the calculation of relevant theoretical predictions. In this paper, we present the results of the 'N5K non-Limber integration challenge', the goal of which was to quantify the performance of different approaches to calculating the angular power spectrum of galaxy number counts and cosmic shear data without invoking the so-called 'Limber approximation', in the context of the Rubin Observatory Legacy Survey of Space and Time (LSST). We quantify the performance, in terms of accuracy and speed, of three non-Limber implementations: ${\tt FKEM (CosmoLike)}$, ${\tt Levin}$, and ${\tt matter}$, themselves based on different integration schemes and approximations. We find that in the challenge's fiducial 3x2pt LSST Year 10 scenario, ${\tt FKEM (CosmoLike)}$ produces the fastest run time within the required accuracy by a considerable margin, positioning it favourably for use in Bayesian parameter inference. This method, however, requires further development and testing to extend its use to certain analysis scenarios, particularly those involving a scale-dependent growth rate. For this and other reasons discussed herein, alternative approaches such as ${\tt matter}$ and ${\tt Levin}$ may be necessary for a full exploration of parameter space. We also find that the usual first-order Limber approximation is insufficiently accurate for LSST Year 10 3x2pt analysis on $\ell=200-1000$, whereas invoking the second-order Limber approximation on these scales (with a full non-Limber method at smaller $\ell$) does suffice. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.04291v2-abstract-full').style.display = 'none'; document.getElementById('2212.04291v2-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 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">15 pages, 8 figures. Journal-accepted 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/2108.13418">arXiv:2108.13418</a> <span> [<a href="https://arxiv.org/pdf/2108.13418">pdf</a>, <a href="https://arxiv.org/format/2108.13418">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/10.21105/astro.2108.13418">10.21105/astro.2108.13418 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The LSST-DESC 3x2pt Tomography Optimization Challenge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zuntz%2C+J">Joe Zuntz</a>, <a href="/search/astro-ph?searchtype=author&query=Lanusse%2C+F">Fran莽ois Lanusse</a>, <a href="/search/astro-ph?searchtype=author&query=Malz%2C+A+I">Alex I. Malz</a>, <a href="/search/astro-ph?searchtype=author&query=Wright%2C+A+H">Angus H. Wright</a>, <a href="/search/astro-ph?searchtype=author&query=Slosar%2C+A">An啪e Slosar</a>, <a href="/search/astro-ph?searchtype=author&query=Abolfathi%2C+B">Bela Abolfathi</a>, <a href="/search/astro-ph?searchtype=author&query=Alonso%2C+D">David Alonso</a>, <a href="/search/astro-ph?searchtype=author&query=Bault%2C+A">Abby Bault</a>, <a href="/search/astro-ph?searchtype=author&query=Bom%2C+C+R">Cl茅cio R. Bom</a>, <a href="/search/astro-ph?searchtype=author&query=Brescia%2C+M">Massimo Brescia</a>, <a href="/search/astro-ph?searchtype=author&query=Broussard%2C+A">Adam Broussard</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Cavuoti%2C+S">Stefano Cavuoti</a>, <a href="/search/astro-ph?searchtype=author&query=Cypriano%2C+E+S">Eduardo S. Cypriano</a>, <a href="/search/astro-ph?searchtype=author&query=Fraga%2C+B+M+O">Bernardo M. O. Fraga</a>, <a href="/search/astro-ph?searchtype=author&query=Gawiser%2C+E">Eric Gawiser</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+E+J">Elizabeth J. Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Green%2C+D">Dylan Green</a>, <a href="/search/astro-ph?searchtype=author&query=Hatfield%2C+P">Peter Hatfield</a>, <a href="/search/astro-ph?searchtype=author&query=Iyer%2C+K">Kartheik Iyer</a>, <a href="/search/astro-ph?searchtype=author&query=Kirkby%2C+D">David Kirkby</a>, <a href="/search/astro-ph?searchtype=author&query=Nicola%2C+A">Andrina Nicola</a>, <a href="/search/astro-ph?searchtype=author&query=Nourbakhsh%2C+E">Erfan Nourbakhsh</a>, <a href="/search/astro-ph?searchtype=author&query=Park%2C+A">Andy Park</a>, <a href="/search/astro-ph?searchtype=author&query=Teixeira%2C+G">Gabriel Teixeira</a> , et al. (3 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="2108.13418v2-abstract-short" style="display: inline;"> This paper presents the results of the Rubin Observatory Dark Energy Science Collaboration (DESC) 3x2pt tomography challenge, which served as a first step toward optimizing the tomographic binning strategy for the main DESC analysis. The task of choosing an optimal tomographic binning scheme for a photometric survey is made particularly delicate in the context of a metacalibrated lensing catalogue… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.13418v2-abstract-full').style.display = 'inline'; document.getElementById('2108.13418v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.13418v2-abstract-full" style="display: none;"> This paper presents the results of the Rubin Observatory Dark Energy Science Collaboration (DESC) 3x2pt tomography challenge, which served as a first step toward optimizing the tomographic binning strategy for the main DESC analysis. The task of choosing an optimal tomographic binning scheme for a photometric survey is made particularly delicate in the context of a metacalibrated lensing catalogue, as only the photometry from the bands included in the metacalibration process (usually riz and potentially g) can be used in sample definition. The goal of the challenge was to collect and compare bin assignment strategies under various metrics of a standard 3x2pt cosmology analysis in a highly idealized setting to establish a baseline for realistically complex follow-up studies; in this preliminary study, we used two sets of cosmological simulations of galaxy redshifts and photometry under a simple noise model neglecting photometric outliers and variation in observing conditions, and contributed algorithms were provided with a representative and complete training set. We review and evaluate the entries to the challenge, finding that even from this limited photometry information, multiple algorithms can separate tomographic bins reasonably well, reaching figures-of-merit scores close to the attainable maximum. We further find that adding the g band to riz photometry improves metric performance by ~15% and that the optimal bin assignment strategy depends strongly on the science case: which figure-of-merit is to be optimized, and which observables (clustering, lensing, or both) are included. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.13418v2-abstract-full').style.display = 'none'; document.getElementById('2108.13418v2-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 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">30 pages (incl. 12 in appendix), 12 figures. Version accepted for publication in the Open Journal of Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> DESC-PUB-00054 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.08455">arXiv:2012.08455</a> <span> [<a href="https://arxiv.org/pdf/2012.08455">pdf</a>, <a href="https://arxiv.org/format/2012.08455">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/10.1093/mnras/stab3640">10.1093/mnras/stab3640 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Scaling pair count to next galaxy surveys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Plaszczynski%2C+S">S. Plaszczynski</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Peloton%2C+J">J. Peloton</a>, <a href="/search/astro-ph?searchtype=author&query=Arnault%2C+C">C. Arnault</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="2012.08455v2-abstract-short" style="display: inline;"> Counting pairs of galaxies or stars according to their distance is at the core of real-space correlation analyzes performed in astrophysics and cosmology. Upcoming galaxy surveys (LSST, Euclid) will measure properties of billions of galaxies challenging our ability to perform such counting in a minute-scale time relevant for the usage of simulations. The problem is only limited by efficient access… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.08455v2-abstract-full').style.display = 'inline'; document.getElementById('2012.08455v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.08455v2-abstract-full" style="display: none;"> Counting pairs of galaxies or stars according to their distance is at the core of real-space correlation analyzes performed in astrophysics and cosmology. Upcoming galaxy surveys (LSST, Euclid) will measure properties of billions of galaxies challenging our ability to perform such counting in a minute-scale time relevant for the usage of simulations. The problem is only limited by efficient access to the data, hence belongs to the big data category. We use the popular Apache Spark framework to address it and design an efficient high-throughput algorithm to deal with hundreds of millions to billions of input data. To optimize it, we revisit the question of nonhierarchical sphere pixelization based on cube symmetries and develop a new one dubbed the "Similar Radius Sphere Pixelization" (SARSPix) with very close to square pixels. It provides the most adapted indexing over the sphere for all distance-related computations. Using LSST-like fast simulations, we compute autocorrelation functions on tomographic bins containing between a hundred million to one billion data points. In each case we achieve the construction of a standard pair-distance histogram in about 2 minutes, using a simple algorithm that is shown to scale, over a moderate number of nodes (16 to 64). This illustrates the potential of this new techniques in the field of astronomy where data access is becoming the main bottleneck. They can be easily adapted to other use-cases as nearest-neighbors search, catalog cross-match or cluster finding. The software is publicly available from https://github.com/astrolabsoftware/SparkCorr. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.08455v2-abstract-full').style.display = 'none'; document.getElementById('2012.08455v2-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">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/2011.05946">arXiv:2011.05946</a> <span> [<a href="https://arxiv.org/pdf/2011.05946">pdf</a>, <a href="https://arxiv.org/format/2011.05946">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/10.1093/mnras/stab1802">10.1093/mnras/stab1802 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Tianlai Dish Pathfinder Array: design, operation and performance of a prototype transit radio interferometer </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wu%2C+F">Fengquan Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+J">Jixia Li</a>, <a href="/search/astro-ph?searchtype=author&query=Zuo%2C+S">Shifan Zuo</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xuelei Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+S">Santanu Das</a>, <a href="/search/astro-ph?searchtype=author&query=Marriner%2C+J+P">John P. Marriner</a>, <a href="/search/astro-ph?searchtype=author&query=Oxholm%2C+T+M">Trevor M. Oxholm</a>, <a href="/search/astro-ph?searchtype=author&query=Phan%2C+A">Anh Phan</a>, <a href="/search/astro-ph?searchtype=author&query=Stebbins%2C+A">Albert Stebbins</a>, <a href="/search/astro-ph?searchtype=author&query=Timbie%2C+P+T">Peter T. Timbie</a>, <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">Reza Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z">Zhiping Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cong%2C+Y">Yanping Cong</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Q">Qizhi Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Y">Yichao Li</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Y">Yingfeng Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Niu%2C+C">Chenhui Niu</a>, <a href="/search/astro-ph?searchtype=author&query=Osinga%2C+C">Calvin Osinga</a>, <a href="/search/astro-ph?searchtype=author&query=Perdereau%2C+O">Olivier Perdereau</a>, <a href="/search/astro-ph?searchtype=author&query=Peterson%2C+J+B">Jeffrey B. Peterson</a>, <a href="/search/astro-ph?searchtype=author&query=Shi%2C+H">Huli Shi</a>, <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+G">Gage Siebert</a>, <a href="/search/astro-ph?searchtype=author&query=Sun%2C+S">Shijie Sun</a> , et al. (12 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="2011.05946v2-abstract-short" style="display: inline;"> The Tianlai Dish Pathfinder Array is a radio interferometer designed to test techniques for 21~cm intensity mapping in the post-reionization universe as a means for measuring large-scale cosmic structure. It performs drift scans of the sky at constant declination. We describe the design, calibration, noise level, and stability of this instrument based on the analysis of about $\sim 5 \%$ of 6,200… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.05946v2-abstract-full').style.display = 'inline'; document.getElementById('2011.05946v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2011.05946v2-abstract-full" style="display: none;"> The Tianlai Dish Pathfinder Array is a radio interferometer designed to test techniques for 21~cm intensity mapping in the post-reionization universe as a means for measuring large-scale cosmic structure. It performs drift scans of the sky at constant declination. We describe the design, calibration, noise level, and stability of this instrument based on the analysis of about $\sim 5 \%$ of 6,200 hours of on-sky observations through October, 2019. Beam pattern determinations using drones and the transit of bright sources are in good agreement, and compatible with electromagnetic simulations. Combining all the baselines, we make maps around bright sources and show that the array behaves as expected. A few hundred hours of observations at different declinations have been used to study the array geometry and pointing imperfections, as well as the instrument noise behaviour. We show that the system temperature is below 80~K for most feed antennas, and that noise fluctuations decrease as expected with integration time, at least up to a few hundred seconds. Analysis of long integrations, from 10 nights of observations of the North Celestial Pole, yielded visibilities with amplitudes of 20-30~mK, consistent with the expected signal from the NCP radio sky with $<10\,$mK precision for $1 ~\mathrm{MHz} \times 1~ \mathrm{min}$ binning. Hi-pass filtering the spectra to remove smooth spectrum signal yields a residual consistent with zero signal at the $0.5\,$mK level. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.05946v2-abstract-full').style.display = 'none'; document.getElementById('2011.05946v2-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">30 pages, 38 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/2009.10185">arXiv:2009.10185</a> <span> [<a href="https://arxiv.org/pdf/2009.10185">pdf</a>, <a href="https://arxiv.org/format/2009.10185">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 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/staa3602">10.1093/mnras/staa3602 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fink, a new generation of broker for the LSST community </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=M%C3%B6ller%2C+A">Anais M枚ller</a>, <a href="/search/astro-ph?searchtype=author&query=Peloton%2C+J">Julien Peloton</a>, <a href="/search/astro-ph?searchtype=author&query=Ishida%2C+E+E+O">Emille E. O. Ishida</a>, <a href="/search/astro-ph?searchtype=author&query=Arnault%2C+C">Chris Arnault</a>, <a href="/search/astro-ph?searchtype=author&query=Bachelet%2C+E">Etienne Bachelet</a>, <a href="/search/astro-ph?searchtype=author&query=Blaineau%2C+T">Tristan Blaineau</a>, <a href="/search/astro-ph?searchtype=author&query=Boutigny%2C+D">Dominique Boutigny</a>, <a href="/search/astro-ph?searchtype=author&query=Chauhan%2C+A">Abhishek Chauhan</a>, <a href="/search/astro-ph?searchtype=author&query=Gangler%2C+E">Emmanuel Gangler</a>, <a href="/search/astro-ph?searchtype=author&query=Hernandez%2C+F">Fabio Hernandez</a>, <a href="/search/astro-ph?searchtype=author&query=Hrivnac%2C+J">Julius Hrivnac</a>, <a href="/search/astro-ph?searchtype=author&query=Leoni%2C+M">Marco Leoni</a>, <a href="/search/astro-ph?searchtype=author&query=Leroy%2C+N">Nicolas Leroy</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">Marc Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Pateyron%2C+S">Sacha Pateyron</a>, <a href="/search/astro-ph?searchtype=author&query=Ramparison%2C+A">Adrien Ramparison</a>, <a href="/search/astro-ph?searchtype=author&query=Turpin%2C+D">Damien Turpin</a>, <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">R茅za Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Allam%2C+T">Tarek Allam Jr.</a>, <a href="/search/astro-ph?searchtype=author&query=Bajat%2C+A">Armelle Bajat</a>, <a href="/search/astro-ph?searchtype=author&query=Biswas%2C+B">Biswajit Biswas</a>, <a href="/search/astro-ph?searchtype=author&query=Boucaud%2C+A">Alexandre Boucaud</a>, <a href="/search/astro-ph?searchtype=author&query=Bregeon%2C+J">Johan Bregeon</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Cohen-Tanugi%2C+J">Johann Cohen-Tanugi</a> , et al. (11 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="2009.10185v3-abstract-short" style="display: inline;"> Fink is a broker designed to enable science with large time-domain alert streams such as the one from the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). It exhibits traditional astronomy broker features such as automatised ingestion, annotation, selection and redistribution of promising alerts for transient science. It is also designed to go beyond traditional broker fe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10185v3-abstract-full').style.display = 'inline'; document.getElementById('2009.10185v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.10185v3-abstract-full" style="display: none;"> Fink is a broker designed to enable science with large time-domain alert streams such as the one from the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). It exhibits traditional astronomy broker features such as automatised ingestion, annotation, selection and redistribution of promising alerts for transient science. It is also designed to go beyond traditional broker features by providing real-time transient classification which is continuously improved by using state-of-the-art Deep Learning and Adaptive Learning techniques. These evolving added values will enable more accurate scientific output from LSST photometric data for diverse science cases while also leading to a higher incidence of new discoveries which shall accompany the evolution of the survey. In this paper we introduce Fink, its science motivation, architecture and current status including first science verification cases using the Zwicky Transient Facility alert stream. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10185v3-abstract-full').style.display = 'none'; document.getElementById('2009.10185v3-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 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">accepted 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/2002.10154">arXiv:2002.10154</a> <span> [<a href="https://arxiv.org/pdf/2002.10154">pdf</a>, <a href="https://arxiv.org/format/2002.10154">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="Image and Video Processing">eess.IV</span> </div> </div> <p class="title is-5 mathjax"> Adversarial training applied to Convolutional Neural Network for photometric redshift predictions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</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="2002.10154v1-abstract-short" style="display: inline;"> The use of Convolutional Neural Networks (CNN) to estimate the galaxy photometric redshift probability distribution by analysing the images in different wavelength bands has been developed in the recent years thanks to the rapid development of the Machine Learning (ML) ecosystem. Authors have set-up CNN architectures and studied their performances and some sources of systematics using standard met… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.10154v1-abstract-full').style.display = 'inline'; document.getElementById('2002.10154v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.10154v1-abstract-full" style="display: none;"> The use of Convolutional Neural Networks (CNN) to estimate the galaxy photometric redshift probability distribution by analysing the images in different wavelength bands has been developed in the recent years thanks to the rapid development of the Machine Learning (ML) ecosystem. Authors have set-up CNN architectures and studied their performances and some sources of systematics using standard methods of training and testing to ensure the generalisation power of their models. So far so good, but one piece was missing : does the model generalisation power is well measured? The present article shows clearly that very small image perturbations can fool the model completely and opens the Pandora's box of \textit{adversarial} attack. Among the different techniques and scenarios, we have chosen to use the Fast Sign Gradient one-step Method and its Projected Gradient Descent iterative extension as adversarial generator tool kit. However, as unlikely as it may seem these adversarial samples which fool not only a single model, reveal a weakness both of the model and the classical training. A revisited algorithm is shown and applied by injecting a fraction of adversarial samples during the training phase. Numerical experiments have been conducted using a specific CNN model for illustration although our study could be applied to other models - not only CNN ones - and in other contexts - not only redshift measurements - as it deals with the complexity of the boundary decision surface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.10154v1-abstract-full').style.display = 'none'; document.getElementById('2002.10154v1-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 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">12 pages, 6 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/1910.07956">arXiv:1910.07956</a> <span> [<a href="https://arxiv.org/pdf/1910.07956">pdf</a>, <a href="https://arxiv.org/format/1910.07956">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/10.1093/mnras/staa345">10.1093/mnras/staa345 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Design, operation and performance of the PAON4 prototype transit interferometer </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">R. Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Charlet%2C+D">D. Charlet</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">M. Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Pailler%2C+C">C. Pailler</a>, <a href="/search/astro-ph?searchtype=author&query=Perdereau%2C+O">O. Perdereau</a>, <a href="/search/astro-ph?searchtype=author&query=Taurigna%2C+M">M. Taurigna</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+J+M">J. M. Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Rigaud%2C+F">F. Rigaud</a>, <a href="/search/astro-ph?searchtype=author&query=Colom%2C+P">P. Colom</a>, <a href="/search/astro-ph?searchtype=author&query=Abbon%2C+P">Ph. Abbon</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">Ch. Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Pezzani%2C+J">J. Pezzani</a>, <a href="/search/astro-ph?searchtype=author&query=Viou%2C+C">C. Viou</a>, <a href="/search/astro-ph?searchtype=author&query=Torchinsky%2C+S+A">S. A. Torchinsky</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Q">Q. Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">J. Zhang</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="1910.07956v2-abstract-short" style="display: inline;"> PAON4 is an L-band (1250-1500 MHz) small interferometer operating in transit mode deployed at the Nan莽ay observatory in France, designed as a prototype instrument for Intensity Mapping. It features four 5~meter diameter dishes in a compact triangular configuration, with a total geometric collecting area of $\sim75 \mathrm{m^2}$, and equipped with dual polarization receivers. A total of 36 visibili… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.07956v2-abstract-full').style.display = 'inline'; document.getElementById('1910.07956v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.07956v2-abstract-full" style="display: none;"> PAON4 is an L-band (1250-1500 MHz) small interferometer operating in transit mode deployed at the Nan莽ay observatory in France, designed as a prototype instrument for Intensity Mapping. It features four 5~meter diameter dishes in a compact triangular configuration, with a total geometric collecting area of $\sim75 \mathrm{m^2}$, and equipped with dual polarization receivers. A total of 36 visibilities are computed from the 8 independent RF signals by the software correlator over the full 250~MHz RF band. The array operates in transit mode, with the dishes pointed toward a fixed declination, while the sky drifts across the instrument. Sky maps for each frequency channel are then reconstructed by combining the time-dependent visibilities from the different baselines observed at different declinations. This paper presents an overview of the PAON4 instrument design and goals, as a prototype for dish arrays to map the Large Scale Structure in radio, using intensity mapping of the atomic hydrogen $21~\mathrm{cm}$ line. We operated PAON4 over several years and use data from observations in different periods to assess the array performance. We present preliminary analysis of a large fraction of this data and discuss crucial issues for this type of instrument, such as the calibration strategy, instrument response stability, and noise behaviour. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.07956v2-abstract-full').style.display = 'none'; document.getElementById('1910.07956v2-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 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 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">17 pages, 16 figures, accepted 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/1812.05995">arXiv:1812.05995</a> <span> [<a href="https://arxiv.org/pdf/1812.05995">pdf</a>, <a href="https://arxiv.org/format/1812.05995">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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> </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/10.3847/1538-4365/ab1658">10.3847/1538-4365/ab1658 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Core Cosmology Library: Precision Cosmological Predictions for LSST </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chisari%2C+N+E">Nora Elisa Chisari</a>, <a href="/search/astro-ph?searchtype=author&query=Alonso%2C+D">David Alonso</a>, <a href="/search/astro-ph?searchtype=author&query=Krause%2C+E">Elisabeth Krause</a>, <a href="/search/astro-ph?searchtype=author&query=Leonard%2C+C+D">C. Danielle Leonard</a>, <a href="/search/astro-ph?searchtype=author&query=Bull%2C+P">Philip Bull</a>, <a href="/search/astro-ph?searchtype=author&query=Neveu%2C+J">J茅r茅my Neveu</a>, <a href="/search/astro-ph?searchtype=author&query=Villarreal%2C+A">Antonia Villarreal</a>, <a href="/search/astro-ph?searchtype=author&query=Singh%2C+S">Sukhdeep Singh</a>, <a href="/search/astro-ph?searchtype=author&query=McClintock%2C+T">Thomas McClintock</a>, <a href="/search/astro-ph?searchtype=author&query=Ellison%2C+J">John Ellison</a>, <a href="/search/astro-ph?searchtype=author&query=Du%2C+Z">Zilong Du</a>, <a href="/search/astro-ph?searchtype=author&query=Zuntz%2C+J">Joe Zuntz</a>, <a href="/search/astro-ph?searchtype=author&query=Mead%2C+A">Alexander Mead</a>, <a href="/search/astro-ph?searchtype=author&query=Joudaki%2C+S">Shahab Joudaki</a>, <a href="/search/astro-ph?searchtype=author&query=Lorenz%2C+C+S">Christiane S. Lorenz</a>, <a href="/search/astro-ph?searchtype=author&query=Troester%2C+T">Tilman Troester</a>, <a href="/search/astro-ph?searchtype=author&query=Sanchez%2C+J">Javier Sanchez</a>, <a href="/search/astro-ph?searchtype=author&query=Lanusse%2C+F">Francois Lanusse</a>, <a href="/search/astro-ph?searchtype=author&query=Ishak%2C+M">Mustapha Ishak</a>, <a href="/search/astro-ph?searchtype=author&query=Hlozek%2C+R">Ren茅e Hlozek</a>, <a href="/search/astro-ph?searchtype=author&query=Blazek%2C+J">Jonathan Blazek</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Almoubayyed%2C+H">Husni Almoubayyed</a>, <a href="/search/astro-ph?searchtype=author&query=Eifler%2C+T">Tim Eifler</a>, <a href="/search/astro-ph?searchtype=author&query=Kirby%2C+M">Matthew Kirby</a> , et al. (5 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="1812.05995v2-abstract-short" style="display: inline;"> The Core Cosmology Library (CCL) provides routines to compute basic cosmological observables to a high degree of accuracy, which have been verified with an extensive suite of validation tests. Predictions are provided for many cosmological quantities, including distances, angular power spectra, correlation functions, halo bias and the halo mass function through state-of-the-art modeling prescripti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1812.05995v2-abstract-full').style.display = 'inline'; document.getElementById('1812.05995v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1812.05995v2-abstract-full" style="display: none;"> The Core Cosmology Library (CCL) provides routines to compute basic cosmological observables to a high degree of accuracy, which have been verified with an extensive suite of validation tests. Predictions are provided for many cosmological quantities, including distances, angular power spectra, correlation functions, halo bias and the halo mass function through state-of-the-art modeling prescriptions available in the literature. Fiducial specifications for the expected galaxy distributions for the Large Synoptic Survey Telescope (LSST) are also included, together with the capability of computing redshift distributions for a user-defined photometric redshift model. A rigorous validation procedure, based on comparisons between CCL and independent software packages, allows us to establish a well-defined numerical accuracy for each predicted quantity. As a result, predictions for correlation functions of galaxy clustering, galaxy-galaxy lensing and cosmic shear are demonstrated to be within a fraction of the expected statistical uncertainty of the observables for the models and in the range of scales of interest to LSST. CCL is an open source software package written in C, with a python interface and publicly available at https://github.com/LSSTDESC/CCL. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1812.05995v2-abstract-full').style.display = 'none'; document.getElementById('1812.05995v2-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, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 December, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">38 pages, 18 figures, matches ApJS accepted 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/1807.03078">arXiv:1807.03078</a> <span> [<a href="https://arxiv.org/pdf/1807.03078">pdf</a>, <a href="https://arxiv.org/format/1807.03078">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> <p class="title is-5 mathjax"> Analyzing billion-objects catalog interactively: Apache Spark for physicists </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Plaszczynski%2C+S">S. Plaszczynski</a>, <a href="/search/astro-ph?searchtype=author&query=Peloton%2C+J">J. Peloton</a>, <a href="/search/astro-ph?searchtype=author&query=Arnault%2C+C">C. Arnault</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E. Campagne</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="1807.03078v2-abstract-short" style="display: inline;"> Apache Spark is a Big Data framework for working on large distributed datasets. Although widely used in the industry, it remains rather limited in the academic community or often restricted to software engineers. The goal of this paper is to show with practical uses-cases that the technology is mature enough to be used without excessive programming skills by astronomers or cosmologists in order to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.03078v2-abstract-full').style.display = 'inline'; document.getElementById('1807.03078v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1807.03078v2-abstract-full" style="display: none;"> Apache Spark is a Big Data framework for working on large distributed datasets. Although widely used in the industry, it remains rather limited in the academic community or often restricted to software engineers. The goal of this paper is to show with practical uses-cases that the technology is mature enough to be used without excessive programming skills by astronomers or cosmologists in order to perform standard analyses over large datasets, as those originating from future galaxy surveys. To demonstrate it, we start from a realistic simulation corresponding to 10 years of LSST data taking (6 billions of galaxies). Then, we design, optimize and benchmark a set of Spark python algorithms in order to perform standard operations as adding photometric redshift errors, measuring the selection function or computing power spectra over tomographic bins. Most of the commands execute on the full 110 GB dataset within tens of seconds and can therefore be performed interactively in order to design full-scale cosmological analyses. A jupyter notebook summarizing the analysis is available at https://github.com/astrolabsoftware/1807.03078. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.03078v2-abstract-full').style.display = 'none'; document.getElementById('1807.03078v2-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 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 July, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1806.04698">arXiv:1806.04698</a> <span> [<a href="https://arxiv.org/pdf/1806.04698">pdf</a>, <a href="https://arxiv.org/format/1806.04698">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> <p class="title is-5 mathjax"> Progress in the Construction and Testing of the Tianlai Radio Interferometers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Das%2C+S">Santanu Das</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+C+J">Christopher J. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">Reza Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Charlet%2C+D">Daniel Charlet</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xuelei Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z">Zhiping Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cianciara%2C+A+J">Aleksander J. Cianciara</a>, <a href="/search/astro-ph?searchtype=author&query=Colom%2C+P">Pierre Colom</a>, <a href="/search/astro-ph?searchtype=author&query=Cong%2C+Y">Yanping Cong</a>, <a href="/search/astro-ph?searchtype=author&query=Gayley%2C+K+G">Kevin G. Gayley</a>, <a href="/search/astro-ph?searchtype=author&query=Geng%2C+J">Jingchao Geng</a>, <a href="/search/astro-ph?searchtype=author&query=Hao%2C+J">Jie Hao</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Q">Qizhi Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Keith%2C+C+S">Celeste S. Keith</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+C">Chao Li</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+J">Jixia Li</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Y">Yichao Li</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+C">Chao Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">Christophe Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Marriner%2C+J+P">John P. Marriner</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+J">Jean-Michel Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">Marc Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Oxholm%2C+T+M">Trevor M. Oxholm</a> , et al. (22 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="1806.04698v2-abstract-short" style="display: inline;"> The Tianlai Pathfinder is designed to demonstrate the feasibility of using a wide field of view radio interferometers to map the density of neutral hydrogen in the Universe after the Epoch of Reionizaton. This approach, called 21~cm intensity-mapping, promises an inexpensive means for surveying the large-scale structure of the cosmos. The Tianlai Pathfinder presently consists of an array of three,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.04698v2-abstract-full').style.display = 'inline'; document.getElementById('1806.04698v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1806.04698v2-abstract-full" style="display: none;"> The Tianlai Pathfinder is designed to demonstrate the feasibility of using a wide field of view radio interferometers to map the density of neutral hydrogen in the Universe after the Epoch of Reionizaton. This approach, called 21~cm intensity-mapping, promises an inexpensive means for surveying the large-scale structure of the cosmos. The Tianlai Pathfinder presently consists of an array of three, 15~m $\times$ 40~m cylinder telescopes and an array of sixteen, 6~m diameter dish antennas located in a radio-quiet part of western China. The two types of arrays were chosen to determine the advantages and disadvantages of each approach. The primary goal of the Pathfinder is to make 3D maps by surveying neutral hydrogen over large areas of the sky %$20,000 {\rm deg}^2$ in two different redshift ranges: first at $1.03 > z > 0.78$ ($700 - 800$~MHz) and later at $0.21 > z > 0.12$ ($1170 - 1270$~MHz). The most significant challenge to $21$~cm intensity-mapping is the removal of strong foreground radiation that dwarfs the cosmological signal. It requires exquisite knowledge of the instrumental response, i.e. calibration. In this paper, we provide an overview of the status of the Pathfinder and discuss the details of some of the analysis that we have carried out to measure the beam function of both arrays. We compare electromagnetic simulations of the arrays to measurements, discuss measurements of the gain and phase stability of the instrument, and provide a brief overview of the data processing pipeline. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1806.04698v2-abstract-full').style.display = 'none'; document.getElementById('1806.04698v2-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 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 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">18 pages, 10 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/1703.02818">arXiv:1703.02818</a> <span> [<a href="https://arxiv.org/pdf/1703.02818">pdf</a>, <a href="https://arxiv.org/format/1703.02818">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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/aa7cf8">10.3847/1538-4357/aa7cf8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A direct method to compute the galaxy count angular correlation function including redshift-space distortions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+-">J. -E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Plaszczynski%2C+S">S. Plaszczynski</a>, <a href="/search/astro-ph?searchtype=author&query=Neveu%2C+J">J. Neveu</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="1703.02818v2-abstract-short" style="display: inline;"> In the near future, cosmology will enter the wide and deep galaxy survey area allowing high-precision studies of the large scale structure of the universe in three dimensions. To test cosmological models and determine their parameters accurately, it is natural to confront data with exact theoretical expectations expressed in the observational parameter space (angles and redshift). The data-driven… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.02818v2-abstract-full').style.display = 'inline'; document.getElementById('1703.02818v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.02818v2-abstract-full" style="display: none;"> In the near future, cosmology will enter the wide and deep galaxy survey area allowing high-precision studies of the large scale structure of the universe in three dimensions. To test cosmological models and determine their parameters accurately, it is natural to confront data with exact theoretical expectations expressed in the observational parameter space (angles and redshift). The data-driven galaxy number count fluctuations on redshift shells, can be used to build correlation functions $C(胃; z_1, z_2)$ on and between shells which can probe the baryonic acoustic oscillations, the distance-redshift distortions as well as gravitational lensing and other relativistic effects. Transforming the model to the data space usually requires the computation of the angular power spectrum $C_\ell(z_1, z_2)$ but this appears as an artificial and inefficient step plagued by apodization issues. In this article we show that it is not necessary and present a compact expression for $C(胃; z_1, z_2)$ that includes directly the leading density and redshift space distortions terms from the full linear theory. It can be evaluated using a fast integration method based on Clenshaw-Curtis quadrature and Chebyshev polynomial series. This new method to compute the correlation functions without any Limber approximation, allows us to produce and discuss maps of the correlation function directly in the observable space and is a significant step towards disentangling the data from the tested models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.02818v2-abstract-full').style.display = 'none'; document.getElementById('1703.02818v2-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 September, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 March, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J.-E. Campagne et al 2017 ApJ 845 28 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1701.03592">arXiv:1701.03592</a> <span> [<a href="https://arxiv.org/pdf/1701.03592">pdf</a>, <a href="https://arxiv.org/format/1701.03592">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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/10.1051/0004-6361/201730399">10.1051/0004-6361/201730399 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Angpow: a software for the fast computation of accurate tomographic power spectra </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+-">J. -E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Neveu%2C+J">J. Neveu</a>, <a href="/search/astro-ph?searchtype=author&query=Plaszczynski%2C+S">S. Plaszczynski</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="1701.03592v2-abstract-short" style="display: inline;"> The statistical distribution of galaxies is a powerful probe to constrain cosmological models and gravity. In particular the matter power spectrum $P(k)$ brings information about the cosmological distance evolution and the galaxy clustering together. However the building of $P(k)$ from galaxy catalogues needs a cosmological model to convert angles on the sky and redshifts into distances, which lea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.03592v2-abstract-full').style.display = 'inline'; document.getElementById('1701.03592v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1701.03592v2-abstract-full" style="display: none;"> The statistical distribution of galaxies is a powerful probe to constrain cosmological models and gravity. In particular the matter power spectrum $P(k)$ brings information about the cosmological distance evolution and the galaxy clustering together. However the building of $P(k)$ from galaxy catalogues needs a cosmological model to convert angles on the sky and redshifts into distances, which leads to difficulties when comparing data with predicted $P(k)$ from other cosmological models, and for photometric surveys like LSST. The angular power spectrum $C_\ell(z_1,z_2)$ between two bins located at redshift $z_1$ and $z_2$ contains the same information than the matter power spectrum, is free from any cosmological assumption, but the prediction of $C_\ell(z_1,z_2)$ from $P(k)$ is a costly computation when performed exactly. The Angpow software aims at computing quickly and accurately the auto ($z_1=z_2$) and cross ($z_1 \neq z_2$) angular power spectra between redshift bins. We describe the developed algorithm, based on developments on the Chebyshev polynomial basis and on the Clenshaw-Curtis quadrature method. We validate the results with other codes, and benchmark the performance. Angpow is flexible and can handle any user defined power spectra, transfer functions, and redshift selection windows. The code is fast enough to be embedded inside programs exploring large cosmological parameter spaces through the $C_\ell(z_1,z_2)$ comparison with data. We emphasize that the Limber's approximation, often used to fasten the computation, gives wrong $C_\ell$ values for cross-correlations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.03592v2-abstract-full').style.display = 'none'; document.getElementById('1701.03592v2-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 June, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 January, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">Published in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 602, A72 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1606.03830">arXiv:1606.03830</a> <span> [<a href="https://arxiv.org/pdf/1606.03830">pdf</a>, <a href="https://arxiv.org/format/1606.03830">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/10.1088/1674-4527/16/10/158">10.1088/1674-4527/16/10/158 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sky reconstruction for the Tianlai cylinder array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">Jiao Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zuo%2C+S">Shifan Zuo</a>, <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">Reza Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xuelei Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Y">Yichao Li</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+F">Fengquan Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">Christophe Magneville</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="1606.03830v1-abstract-short" style="display: inline;"> In this paper, we apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on the spherical harmonic decomposition, and can be applied to cylindrical array as well as dish arrays and we can compute the instrument response, synthesised beam, transfer function and the noise power spectrum. We consider cylinder arrays with feed spacin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.03830v1-abstract-full').style.display = 'inline'; document.getElementById('1606.03830v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1606.03830v1-abstract-full" style="display: none;"> In this paper, we apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on the spherical harmonic decomposition, and can be applied to cylindrical array as well as dish arrays and we can compute the instrument response, synthesised beam, transfer function and the noise power spectrum. We consider cylinder arrays with feed spacing larger than half wavelength, and as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome, using arrays with different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configurations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.03830v1-abstract-full').style.display = 'none'; document.getElementById('1606.03830v1-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 June, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">15 pages, 12 figures, accepted by RAA</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1606.03090">arXiv:1606.03090</a> <span> [<a href="https://arxiv.org/pdf/1606.03090">pdf</a>, <a href="https://arxiv.org/format/1606.03090">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/10.1093/mnras/stw1458">10.1093/mnras/stw1458 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sky reconstruction from transit visibilities: PAON-4 and Tianlai Dish Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">Jiao Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">Reza Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xuelei Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">Christophe Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+F">Fengquan Wu</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="1606.03090v1-abstract-short" style="display: inline;"> The spherical harmonics $m$-mode decomposition is a powerful sky map reconstruction method suitable for radio interferometers operating in transit mode. It can be applied to various configurations, including dish arrays and cylinders. We describe the computation of the instrument response function, the point spread function (PSF), transfer function, the noise covariance matrix and noise power spec… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.03090v1-abstract-full').style.display = 'inline'; document.getElementById('1606.03090v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1606.03090v1-abstract-full" style="display: none;"> The spherical harmonics $m$-mode decomposition is a powerful sky map reconstruction method suitable for radio interferometers operating in transit mode. It can be applied to various configurations, including dish arrays and cylinders. We describe the computation of the instrument response function, the point spread function (PSF), transfer function, the noise covariance matrix and noise power spectrum. The analysis in this paper is focused on dish arrays operating in transit mode. We show that arrays with regular spacing have more pronounced side lobes as well as structures in their noise power spectrum, compared to arrays with irregular spacing, specially in the north-south direction. A good knowledge of the noise power spectrum $C^{\mathrm{noise}}(\ell)$ is essential for intensity mapping experiments as non uniform $C^{\mathrm{noise}}(\ell)$ is a potential problem for the measurement of the HI power spectrum. Different configurations have been studied to optimise the PAON-4 and Tianlai dish array layouts. We present their expected performance and their sensitivities to the 21-cm emission of the Milky Way and local extragalactic HI clumps <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.03090v1-abstract-full').style.display = 'none'; document.getElementById('1606.03090v1-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 June, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">20 pages, 18 figures - Submitted to MNRAS ( the appendix A,B are not included in the accepted 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/1505.02623">arXiv:1505.02623</a> <span> [<a href="https://arxiv.org/pdf/1505.02623">pdf</a>, <a href="https://arxiv.org/format/1505.02623">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/10.1007/s10686-015-9477-7">10.1007/s10686-015-9477-7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On sky characterization of the BAORadio wide band digital backend: Search for HI emission in Abell85, Abell1205 and Abell2440 galaxy clusters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">R. Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Colom%2C+P">P. Colom</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrari%2C+C">C. Ferrari</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">Ch. Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+J+M">J. M. Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">M. Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Torrento%2C+A+S">A. S. Torrento</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="1505.02623v1-abstract-short" style="display: inline;"> We have observed regions of three galaxy clusters at z$\sim$ [0.06, 0.09] (Abell85, Abell1205, Abell2440), as well as calibration sources with the Nancay radiotelescope (NRT) to search for 21 cm emission and fully characterize the FPGA based BAORadio digital backend. The total observation time of few hours per source have been distributed over few months, from March 2011 to January 2012, due to sc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1505.02623v1-abstract-full').style.display = 'inline'; document.getElementById('1505.02623v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1505.02623v1-abstract-full" style="display: none;"> We have observed regions of three galaxy clusters at z$\sim$ [0.06, 0.09] (Abell85, Abell1205, Abell2440), as well as calibration sources with the Nancay radiotelescope (NRT) to search for 21 cm emission and fully characterize the FPGA based BAORadio digital backend. The total observation time of few hours per source have been distributed over few months, from March 2011 to January 2012, due to scheduling constraints of the NRT, which is a transit telescope. Data have been acquired in parallel with the NRT standard correlator (ACRT) back-end, as well as with the BAORadio data acquisition system. The latter enables wide band instantaneous observation of the [1250, 1500]MHz frequency range, as well as the use of powerful RFI mitigation methods thanks to its fine time sampling. A number of questions related to instrument stability, data processing and calibration are discussed. We have obtained the radiometer curves over the integration time range [0.01,10 000] seconds and we show that sensitivities of few mJy over most of the wide frequency band can be reached with the NRT. It is clearly shown that in blind line search, which is the context of HI intensity mapping for Baryon Acoustic Oscillations, the new acquisition system and processing pipeline outperforms the standard one. We report a positive detection of 21 cm emission at 3 sigma-level from galaxies in the outer region of Abell85 at 1352 MHz (14 400 km/s) corresponding to a line strength of 0.8 Jy km/s. We observe also an excess power around 1318 MHz (21 600 km/s), although at lower statistical significance, compatible with emission from Abell1205 galaxies. Detected radio line emissions have been cross matched with optical catalogs and we have derived hydrogen mass estimates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1505.02623v1-abstract-full').style.display = 'none'; document.getElementById('1505.02623v1-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 May, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">18 pages, 17 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/1209.3266">arXiv:1209.3266</a> <span> [<a href="https://arxiv.org/pdf/1209.3266">pdf</a>, <a href="https://arxiv.org/format/1209.3266">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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> </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/10.1016/j.crhy.2011.11.003">10.1016/j.crhy.2011.11.003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> BAORadio: A digital pipeline for radio interferometry and 21 cm mapping of large scale structures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">R茅za Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J">Jean-Eric Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Colom%2C+P">Pierre Colom</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">Christophe Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+J">Jean-Michel Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">Marc Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Rich%2C+J">James Rich</a>, <a href="/search/astro-ph?searchtype=author&query=Y%C3%A8che%2C+C">Christophe Y猫che</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="1209.3266v1-abstract-short" style="display: inline;"> 3D mapping of matter distribution in the universe through the 21 cm radio emission of atomic hydrogen HI is a complementary approach to optical surveys for the study of the Large Scale Structures, in particular for measuring the BAO (Baryon Acoustic Oscillation) scale up to redshifts z < 3, and therefore constraining dark energy parameters. We propose a novel method to map the HI mass distribution… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1209.3266v1-abstract-full').style.display = 'inline'; document.getElementById('1209.3266v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1209.3266v1-abstract-full" style="display: none;"> 3D mapping of matter distribution in the universe through the 21 cm radio emission of atomic hydrogen HI is a complementary approach to optical surveys for the study of the Large Scale Structures, in particular for measuring the BAO (Baryon Acoustic Oscillation) scale up to redshifts z < 3, and therefore constraining dark energy parameters. We propose a novel method to map the HI mass distribution in three dimensions in radio, without detecting or identifying individual compact sources. This method would require an instrument with a large instantaneous bandwidth (> 100 MHz) and high sensitivity, while a rather modest angular resolution (~ 10 arcmin) should be sufficient. These requirements can be met by a dense interferometric array or a phased array (FPA) in the focal plane of a large primary reflector, representing a total collecting area of a few thousand square meters with few hundred simultaneous beams covering a 20 to 100 square degrees field of view. We describe the development and qualification of an electronic and data processing system for digital radio interferometry and beam forming suitable for such instruments with several hundred receiver elements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1209.3266v1-abstract-full').style.display = 'none'; document.getElementById('1209.3266v1-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 September, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2012. </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, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Comptes Rendus Physique (Comptes Rendus de l'Academie des Sciences - Series IV - Physics - Astrophysics) Volume 13, Issue 1 (2012) pages 46-53 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1108.1474">arXiv:1108.1474</a> <span> [<a href="https://arxiv.org/pdf/1108.1474">pdf</a>, <a href="https://arxiv.org/format/1108.1474">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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/10.1051/0004-6361/201117837">10.1051/0004-6361/201117837 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> 21 cm observation of LSS at z~1 Instrument sensitivity and foreground subtraction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">R. Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Colom%2C+P">P. Colom</a>, <a href="/search/astro-ph?searchtype=author&query=Goff%2C+J+M+L">J. M. Le Goff</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">C. Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+J+M">J. M. Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">M. Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Rich%2C+J">J. Rich</a>, <a href="/search/astro-ph?searchtype=author&query=Y%C3%A8che%2C+C">C. Y猫che</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="1108.1474v1-abstract-short" style="display: inline;"> Large Scale Structures (LSS) in the universe can be traced using the neutral atomic hydrogen HI through its 21cm emission. Such a 3D matter distribution map can be used to test the Cosmological model and to constrain the Dark Energy properties or its equation of state. A novel approach, called intensity mapping can be used to map the HI distribution, using radio interferometers with large instanta… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1108.1474v1-abstract-full').style.display = 'inline'; document.getElementById('1108.1474v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1108.1474v1-abstract-full" style="display: none;"> Large Scale Structures (LSS) in the universe can be traced using the neutral atomic hydrogen HI through its 21cm emission. Such a 3D matter distribution map can be used to test the Cosmological model and to constrain the Dark Energy properties or its equation of state. A novel approach, called intensity mapping can be used to map the HI distribution, using radio interferometers with large instantaneous field of view and waveband. In this paper, we study the sensitivity of different radio interferometer configurations, or multi-beam instruments for the observation of large scale structures and BAO oscillations in 21cm and we discuss the problem of foreground removal. For each configuration, we determine instrument response by computing the (u,v) or Fourier angular frequency plane coverage using visibilities. The (u,v) plane response is the noise power spectrum, hence the instrument sensitivity for LSS P(k) measurement. We describe also a simple foreground subtraction method to separate LSS 21 cm signal from the foreground due to the galactic synchrotron and radio sources emission. We have computed the noise power spectrum for different instrument configuration as well as the extracted LSS power spectrum, after separation of 21cm-LSS signal from the foregrounds. We have also obtained the uncertainties on the Dark Energy parameters for an optimized 21 cm BAO survey. We show that a radio instrument with few hundred simultaneous beams and a collecting area of ~10000 m^2 will be able to detect BAO signal at redshift z ~ 1 and will be competitive with optical surveys. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1108.1474v1-abstract-full').style.display = 'none'; document.getElementById('1108.1474v1-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 August, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2011. </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, 18 figures submitted to Astronomy & Astrophysics (A&A)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">ACM Class:</span> J.2 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1106.5659">arXiv:1106.5659</a> <span> [<a href="https://arxiv.org/pdf/1106.5659">pdf</a>, <a href="https://arxiv.org/format/1106.5659">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"> BAORadio : Cartographie 3D de la distribution de gaz H$_I$ dans l'Univers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ansari%2C+R">R. Ansari</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Colom%2C+P">P. Colom</a>, <a href="/search/astro-ph?searchtype=author&query=Magneville%2C+C">C. Magneville</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+J+M">J. M. Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Moniez%2C+M">M. Moniez</a>, <a href="/search/astro-ph?searchtype=author&query=Rich%2C+J">J. Rich</a>, <a href="/search/astro-ph?searchtype=author&query=Y%C3%A8che%2C+C">C. Y猫che</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="1106.5659v1-abstract-short" style="display: inline;"> 3D mapping of matter distribution in the universe through the 21 cm radio emission of atomic hydrogen is a complementary approach to optical surveys for the study of the Large Scale Structures, in particular for measuring the BAO (Baryon Acoustic Oscillation) scale up to redshifts z <~ 3 and constrain dark energy. We propose to carry such a survey through a novel method, called intensity mapping,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1106.5659v1-abstract-full').style.display = 'inline'; document.getElementById('1106.5659v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1106.5659v1-abstract-full" style="display: none;"> 3D mapping of matter distribution in the universe through the 21 cm radio emission of atomic hydrogen is a complementary approach to optical surveys for the study of the Large Scale Structures, in particular for measuring the BAO (Baryon Acoustic Oscillation) scale up to redshifts z <~ 3 and constrain dark energy. We propose to carry such a survey through a novel method, called intensity mapping, without detecting individual galaxies radio emission. This method requires a wide band instrument, 100 MHz or larger, and multiple beams, while a rather modest angular resolution of 10 arcmin would be sufficient. The instrument would have a few thousand square meters of collecting area and few hundreds of simultaneous beams. These constraints could be fulfilled with a dense array of receivers in interferometric mode, or a phased array at the focal plane of a large antenna. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1106.5659v1-abstract-full').style.display = 'none'; document.getElementById('1106.5659v1-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 June, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LAL 11-70 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Conference proceedings - Contribution aux Journ茅es Scientifiques "Les radiot茅lescopes du Futur. Technologies et avanc茅es scientifiques" - 29-30 mars 2011, Paris </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1001.0077">arXiv:1001.0077</a> <span> [<a href="https://arxiv.org/pdf/1001.0077">pdf</a>, <a href="https://arxiv.org/ps/1001.0077">ps</a>, <a href="https://arxiv.org/format/1001.0077">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 Detectors">physics.ins-det</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="High Energy Physics - Experiment">hep-ex</span> </div> </div> <p class="title is-5 mathjax"> The LAGUNA design study- towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=LAGUNA+Collaboration"> LAGUNA Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Angus%2C+D">D. Angus</a>, <a href="/search/astro-ph?searchtype=author&query=Ariga%2C+A">A. Ariga</a>, <a href="/search/astro-ph?searchtype=author&query=Autiero%2C+D">D. Autiero</a>, <a href="/search/astro-ph?searchtype=author&query=Apostu%2C+A">A. Apostu</a>, <a href="/search/astro-ph?searchtype=author&query=Badertscher%2C+A">A. Badertscher</a>, <a href="/search/astro-ph?searchtype=author&query=Bennet%2C+T">T. Bennet</a>, <a href="/search/astro-ph?searchtype=author&query=Bertola%2C+G">G. Bertola</a>, <a href="/search/astro-ph?searchtype=author&query=Bertola%2C+P+F">P. F. Bertola</a>, <a href="/search/astro-ph?searchtype=author&query=Besida%2C+O">O. Besida</a>, <a href="/search/astro-ph?searchtype=author&query=Bettini%2C+A">A. Bettini</a>, <a href="/search/astro-ph?searchtype=author&query=Booth%2C+C">C. Booth</a>, <a href="/search/astro-ph?searchtype=author&query=Borne%2C+J+L">J. L. Borne</a>, <a href="/search/astro-ph?searchtype=author&query=Brancus%2C+I">I. Brancus</a>, <a href="/search/astro-ph?searchtype=author&query=Bujakowsky%2C+W">W. Bujakowsky</a>, <a href="/search/astro-ph?searchtype=author&query=Campagne%2C+J+E">J. E. Campagne</a>, <a href="/search/astro-ph?searchtype=author&query=Danil%2C+G+C">G. Cata Danil</a>, <a href="/search/astro-ph?searchtype=author&query=Chipesiu%2C+F">F. Chipesiu</a>, <a href="/search/astro-ph?searchtype=author&query=Chorowski%2C+M">M. Chorowski</a>, <a href="/search/astro-ph?searchtype=author&query=Cripps%2C+J">J. Cripps</a>, <a href="/search/astro-ph?searchtype=author&query=Curioni%2C+A">A. Curioni</a>, <a href="/search/astro-ph?searchtype=author&query=Davidson%2C+S">S. Davidson</a>, <a href="/search/astro-ph?searchtype=author&query=Declais%2C+Y">Y. Declais</a>, <a href="/search/astro-ph?searchtype=author&query=Drost%2C+U">U. Drost</a>, <a href="/search/astro-ph?searchtype=author&query=Duliu%2C+O">O. Duliu</a> , et al. (99 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="1001.0077v1-abstract-short" style="display: inline;"> The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are being studied: Boulby (UK), Canfranc (Spain), F… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1001.0077v1-abstract-full').style.display = 'inline'; document.getElementById('1001.0077v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1001.0077v1-abstract-full" style="display: none;"> The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are being studied: Boulby (UK), Canfranc (Spain), Fr茅jus (France/Italy), Pyh盲salmi (Finland), Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The design study aims at the comprehensive and coordinated technical assessment of each site, at a coherent cost estimation, and at a prioritization of the sites within the summer 2010. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1001.0077v1-abstract-full').style.display = 'none'; document.getElementById('1001.0077v1-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 December, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2010. </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">5 pages, contribution to the Workshop "European Strategy for Future Neutrino Physics", CERN, Oct. 2009</span> </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: 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