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class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.07347">arXiv:2501.07347</a> <span> [<a href="https://arxiv.org/pdf/2501.07347">pdf</a>, <a href="https://arxiv.org/format/2501.07347">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A multi-wavelength view of the isolated neutron star eRASSU J065715.3+260428 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kurpas%2C+J">J. Kurpas</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">A. D. Schwope</a>, <a href="/search/?searchtype=author&query=Pan%2C+Z+C">Z. C. Pan</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Z+L">Z. L. Zhang</a>, <a href="/search/?searchtype=author&query=Qian%2C+L">L. Qian</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a>, <a href="/search/?searchtype=author&query=Ji%2C+L">L. Ji</a>, <a href="/search/?searchtype=author&query=Traulsen%2C+I">I. Traulsen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2501.07347v1-abstract-short" style="display: inline;"> The X-ray source eRASSU J065715.3+260428 was identified as a likely thermally emitting isolated neutron star in a search in the SRG/eROSITA All-Sky Survey. We investigated the nature and evolutionary state of the source through a dedicated multi-wavelength follow-up campaign with XMM-Newton, NICER, FAST, and ESO-VLT, complemented by the analysis of archival Fermi-LAT observations. The X-ray observ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.07347v1-abstract-full').style.display = 'inline'; document.getElementById('2501.07347v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.07347v1-abstract-full" style="display: none;"> The X-ray source eRASSU J065715.3+260428 was identified as a likely thermally emitting isolated neutron star in a search in the SRG/eROSITA All-Sky Survey. We investigated the nature and evolutionary state of the source through a dedicated multi-wavelength follow-up campaign with XMM-Newton, NICER, FAST, and ESO-VLT, complemented by the analysis of archival Fermi-LAT observations. The X-ray observations unveiled the rotation period, $P=261.085400(4)$ ms, and spin-down rate, $\dot{P}=6^{+11}_{-4}\times10^{-15}$ s s$^{-1}$, of the source. No optical counterparts are detected down to 27.3 mag ($5蟽$, R band), implying a large X-ray-to-optical flux ratio above 5200. The X-ray spectrum of the source is best described by a composite phenomenological model consisting of two thermal components, either a double blackbody continuum with temperatures 90 eV and 220 eV or a hydrogen neutron star atmosphere of temperature $\log(T/\mathrm{K})\sim 5.8$ combined with a hot blackbody of 250 eV, in both cases modified by an absorption feature at low energies ($\sim0.3$ keV). The presence of faint non-thermal hard X-ray tails is ruled out above $(2.1\pm1.8)$% of the source unabsorbed flux. Radio searches at $1-1.5$ GHz with FAST yielded negative results, with a deep upper limit on the pulsed flux of 1.4 $渭$Jy ($10蟽$). Similarly, no significant spatial or pulsed signals were detected in sixteen years of Fermi-LAT observations. The source is most likely a middle-aged spin-powered pulsar and can also be identified as PSR J0657+2604. The absence of non-thermal X-ray, radio, or gamma-ray emission within current limits suggests either an unfavourable viewing geometry or unusual magnetospheric properties. Additional observations are needed to check for faint hard X-ray tails, investigate the presence of diffuse emission from a pulsar-wind nebula, and obtain a more accurately sampled timing solution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.07347v1-abstract-full').style.display = 'none'; document.getElementById('2501.07347v1-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 8 figures, accepted for publication in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.03870">arXiv:2412.03870</a> <span> [<a href="https://arxiv.org/pdf/2412.03870">pdf</a>, <a href="https://arxiv.org/format/2412.03870">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1002/asna.20240116">10.1002/asna.20240116 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Isolated neutron stars as Science Validation for XMM2ATHENA: Ensuring robust data for future X-ray Astronomy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana Mancini Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">Axel Schwope</a>, <a href="/search/?searchtype=author&query=Traulsen%2C+I">Iris Traulsen</a>, <a href="/search/?searchtype=author&query=Ballet%2C+J">Jean Ballet</a>, <a href="/search/?searchtype=author&query=Chakraborty%2C+S">Sudip Chakraborty</a>, <a href="/search/?searchtype=author&query=Homan%2C+D">David Homan</a>, <a href="/search/?searchtype=author&query=Kurpas%2C+J">Jan Kurpas</a>, <a href="/search/?searchtype=author&query=Gomez-Moran%2C+A+N">Ada Nebot Gomez-Moran</a>, <a href="/search/?searchtype=author&query=Pineau%2C+F">Francois-Xavier Pineau</a>, <a href="/search/?searchtype=author&query=Tranin%2C+H">Hugo Tranin</a>, <a href="/search/?searchtype=author&query=Webb%2C+N">Natalie Webb</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="2412.03870v1-abstract-short" style="display: inline;"> The discovery of radio-quiet, X-ray thermally emitting isolated neutron stars (XINSs) in the ROSAT All-Sky Survey revealed a previously overlooked component of the neutron star population. Advancements in X-ray instrumentation and the availability of deep, wide-area optical surveys now enable us to explore XINSs at fainter X-ray fluxes and greater distances. In this study, we investigated candidat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.03870v1-abstract-full').style.display = 'inline'; document.getElementById('2412.03870v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.03870v1-abstract-full" style="display: none;"> The discovery of radio-quiet, X-ray thermally emitting isolated neutron stars (XINSs) in the ROSAT All-Sky Survey revealed a previously overlooked component of the neutron star population. Advancements in X-ray instrumentation and the availability of deep, wide-area optical surveys now enable us to explore XINSs at fainter X-ray fluxes and greater distances. In this study, we investigated candidates selected from the 4XMM-DR9 catalogue using XMM-Newton, focusing on long-term flux stability, spectral characterisation, and astrometry. By leveraging resources from the XMM2ATHENA project -- including updated catalogues, multiwavelength characterisation and machine learning classification -- we refined our understanding of this sample of soft X-ray emitters. Our findings enhance the characterisation of XINS candidates, laying the groundwork for more targeted investigations and future catalogue searches. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.03870v1-abstract-full').style.display = 'none'; document.getElementById('2412.03870v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 3 figures, proceedings of IWARA 2024, 11th International Workshop on Astronomy and Relativistic Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.12846">arXiv:2405.12846</a> <span> [<a href="https://arxiv.org/pdf/2405.12846">pdf</a>, <a href="https://arxiv.org/format/2405.12846">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Thermally emitting isolated neutron star candidates from the SRG/eROSITA All-Sky Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kurpas%2C+J">J. Kurpas</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">A. D. Schwope</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.12846v1-abstract-short" style="display: inline;"> The SRG/eROSITA All-Sky Survey (eRASS) allows for the creation of a complete sample of X-ray dim isolated neutron stars (XDINSs), which will significantly facilitate the study of their population properties, evolution, and connection to other families of isolated neutron stars (INSs). In this work, we conduct a systematic search for XDINSs on the western Galactic hemisphere and discuss the resulti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.12846v1-abstract-full').style.display = 'inline'; document.getElementById('2405.12846v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.12846v1-abstract-full" style="display: none;"> The SRG/eROSITA All-Sky Survey (eRASS) allows for the creation of a complete sample of X-ray dim isolated neutron stars (XDINSs), which will significantly facilitate the study of their population properties, evolution, and connection to other families of isolated neutron stars (INSs). In this work, we conduct a systematic search for XDINSs on the western Galactic hemisphere and discuss the resulting candidate sample. Consistently with the properties of the known XDINSs, we selected all eRASS sources possessing a soft X-ray spectral distribution and that are unlikely to be associated with optical or infrared sources. Our selection criteria allowed us to recover all known XDINSs and previously proposed candidates. In addition, we put forward 33 new candidate members for dedicated follow-up identification campaigns. We found the resulting candidate sample to be about 30-50% complete, mainly due to source confusion and the stringent cross-matching criteria adopted. The candidates of the sample presented here can be divided into two groups: 13 soft and 20 somewhat hard X-ray emitters. Interestingly, the thermal nature, spatial distribution, lack of known counterparts, and absence of significant flux variability of the candidates in the first group agree well with the properties of other confirmed thermally emitting INSs. For the candidates in the second group, the current observational data do not allow one to discern between rotation-powered or recycled pulsars, cataclysmic variables, or quiescent neutron stars in binary systems or even to rule out an extragalactic nature. On the basis of population synthesis and the estimated source completeness of the search, we expect that between one and three new XDINSs are among the already singled-out list of XDINS candidates - a long-sought increase in the proposed number of members of this elusive class of X-ray emitters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.12846v1-abstract-full').style.display = 'none'; document.getElementById('2405.12846v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 9 figures, accepted for publication in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.17290">arXiv:2401.17290</a> <span> [<a href="https://arxiv.org/pdf/2401.17290">pdf</a>, <a href="https://arxiv.org/format/2401.17290">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Detection of pulsed X-ray emission from the isolated neutron star candidate eRASSU J131716.9-402647 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kurpas%2C+J">J. Kurpas</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">A. D. Schwope</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</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="2401.17290v1-abstract-short" style="display: inline;"> The X-ray source eRASSU J131716.9-402647 was recently identified from observations with Spectrum Roentgen Gamma (SRG)/eROSITA as a promising X-ray dim isolated neutron star (XDINS) candidate on the premise of a soft energy distribution, absence of catalogued counterparts, and a high X-ray-to-optical flux ratio. Here, we report the results of a multi-wavelength observational campaign with XMM-Newto… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.17290v1-abstract-full').style.display = 'inline'; document.getElementById('2401.17290v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.17290v1-abstract-full" style="display: none;"> The X-ray source eRASSU J131716.9-402647 was recently identified from observations with Spectrum Roentgen Gamma (SRG)/eROSITA as a promising X-ray dim isolated neutron star (XDINS) candidate on the premise of a soft energy distribution, absence of catalogued counterparts, and a high X-ray-to-optical flux ratio. Here, we report the results of a multi-wavelength observational campaign with XMM-Newton, NICER and the FORS2 instrument at the ESO-VLT. We found in both the XMM-Newton and NICER data that the X-ray emission is strongly pulsed at a period of $12.757$ s (pulsed fraction $p_\mathrm{f} = (29.1 \pm 2.6)$% in the 0.2-2 keV band). The pulse profile is double-humped, and the pulsed fraction increases with energy. The XMM-Newton and NICER epochs allow us to derive a 3$蟽$ upper limit of $\dot{P}\leq 8\times 10^{-11}$ s s$^{-1}$ on the spin-down rate of the neutron star. The source spectrum is well described by a purely thermal continuum, either a blackbody with $kT\sim95$ eV or a magnetised neutron star atmosphere model with $kT \sim 35$ eV. Similarly to other thermally emitting isolated neutron stars, we found in either case strong deviations from the continuum, a broad absorption feature at energy $\sim260$ eV and a narrow one around $590$ eV. The FORS2 instrument at ESO-VLT has not detected the optical counterpart ($m_\mathrm{R}>27.5$ mag, $5蟽$ detection limit), implying an X-ray-to-optical flux ratio of $10^4$ at least. The properties of eRASSU J131716.9-402647 strongly resemble those of a highly magnetised isolated neutron star and favour an XDINS or high-B pulsar nature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.17290v1-abstract-full').style.display = 'none'; document.getElementById('2401.17290v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 9 figures, accepted for publication in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.17274">arXiv:2401.17274</a> <span> [<a href="https://arxiv.org/pdf/2401.17274">pdf</a>, <a href="https://arxiv.org/format/2401.17274">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202347165">10.1051/0004-6361/202347165 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The SRG/eROSITA all-sky survey: First X-ray catalogues and data release of the western Galactic hemisphere </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Merloni%2C+A">A. Merloni</a>, <a href="/search/?searchtype=author&query=Lamer%2C+G">G. Lamer</a>, <a href="/search/?searchtype=author&query=Liu%2C+T">T. Liu</a>, <a href="/search/?searchtype=author&query=Ramos-Ceja%2C+M+E">M. E. Ramos-Ceja</a>, <a href="/search/?searchtype=author&query=Brunner%2C+H">H. Brunner</a>, <a href="/search/?searchtype=author&query=Bulbul%2C+E">E. Bulbul</a>, <a href="/search/?searchtype=author&query=Dennerl%2C+K">K. Dennerl</a>, <a href="/search/?searchtype=author&query=Doroshenko%2C+V">V. Doroshenko</a>, <a href="/search/?searchtype=author&query=Freyberg%2C+M+J">M. J. Freyberg</a>, <a href="/search/?searchtype=author&query=Friedrich%2C+S">S. Friedrich</a>, <a href="/search/?searchtype=author&query=Gatuzz%2C+E">E. Gatuzz</a>, <a href="/search/?searchtype=author&query=Georgakakis%2C+A">A. Georgakakis</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a>, <a href="/search/?searchtype=author&query=Igo%2C+Z">Z. Igo</a>, <a href="/search/?searchtype=author&query=Kreykenbohm%2C+I">I. Kreykenbohm</a>, <a href="/search/?searchtype=author&query=Liu%2C+A">A. Liu</a>, <a href="/search/?searchtype=author&query=Maitra%2C+C">C. Maitra</a>, <a href="/search/?searchtype=author&query=Malyali%2C+A">A. Malyali</a>, <a href="/search/?searchtype=author&query=Mayer%2C+M+G+F">M. G. F. Mayer</a>, <a href="/search/?searchtype=author&query=Nandra%2C+K">K. Nandra</a>, <a href="/search/?searchtype=author&query=Predehl%2C+P">P. Predehl</a>, <a href="/search/?searchtype=author&query=Robrade%2C+J">J. Robrade</a>, <a href="/search/?searchtype=author&query=Salvato%2C+M">M. Salvato</a>, <a href="/search/?searchtype=author&query=Sanders%2C+J+S">J. S. Sanders</a>, <a href="/search/?searchtype=author&query=Stewart%2C+I">I. Stewart</a> , et al. (120 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="2401.17274v1-abstract-short" style="display: inline;"> The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sky maps of an unprecedented depth. Here we present catalogues of both point-like and extended sources using the data acquired in the first six months of survey operations (eRASS1; completed June 2020) over the half sky wh… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.17274v1-abstract-full').style.display = 'inline'; document.getElementById('2401.17274v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.17274v1-abstract-full" style="display: none;"> The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sky maps of an unprecedented depth. Here we present catalogues of both point-like and extended sources using the data acquired in the first six months of survey operations (eRASS1; completed June 2020) over the half sky whose proprietary data rights lie with the German eROSITA Consortium. We describe the observation process, the data analysis pipelines, and the characteristics of the X-ray sources. With nearly 930000 entries detected in the most sensitive 0.2-2.3 keV energy range, the eRASS1 main catalogue presented here increases the number of known X-ray sources in the published literature by more than 60%, and provides a comprehensive inventory of all classes of X-ray celestial objects, covering a wide range of physical processes. A smaller catalogue of 5466 sources detected in the less sensitive but harder 2.3-5 keV band is the result of the first true imaging survey of the entire sky above 2 keV. We show that the number counts of X-ray sources in eRASS1 are consistent with those derived over narrower fields by past X-ray surveys of a similar depth, and we explore the number counts variation as a function of the location in the sky. Adopting a uniform all-sky flux limit (at 50% completeness) of F_{0.5-2 keV} > 5 \times 10^{-14}$ erg\,s$^{-1}$\,cm$^{-2}$, we estimate that the eROSITA all-sky survey resolves into individual sources about 20% of the cosmic X-ray background in the 1-2 keV range. The catalogues presented here form part of the first data release (DR1) of the SRG/eROSITA all-sky survey. Beyond the X-ray catalogues, DR1 contains all detected and calibrated event files, source products (light curves and spectra), and all-sky maps. Illustrative examples of these are provided. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.17274v1-abstract-full').style.display = 'none'; document.getElementById('2401.17274v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">39 pages, 23 figures. Accepted for publication in A&A. Accompanying eROSITA-DE Data Release 1</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, vol. 682, A34 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.14066">arXiv:2304.14066</a> <span> [<a href="https://arxiv.org/pdf/2304.14066">pdf</a>, <a href="https://arxiv.org/format/2304.14066">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346375">10.1051/0004-6361/202346375 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery of two promising isolated neutron star candidates in the SRG/eROSITA All-Sky Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kurpas%2C+J">J. Kurpas</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">A. D. Schwope</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a>, <a href="/search/?searchtype=author&query=Buckley%2C+D+A+H">D. A. H. Buckley</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="2304.14066v1-abstract-short" style="display: inline;"> We report the discovery of the isolated neutron star (INS) candidates eRASSU J065715.3+260428 and eRASSU J131716.9-402647 from the Spectrum Roentgen Gamma (SRG) eROSITA All-Sky Survey. Selected for their soft X-ray emission and absence of catalogued counterparts, both objects were recently targeted with the Large Binocular Telescope and the Southern African Large Telescope. The absence of counterp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.14066v1-abstract-full').style.display = 'inline'; document.getElementById('2304.14066v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.14066v1-abstract-full" style="display: none;"> We report the discovery of the isolated neutron star (INS) candidates eRASSU J065715.3+260428 and eRASSU J131716.9-402647 from the Spectrum Roentgen Gamma (SRG) eROSITA All-Sky Survey. Selected for their soft X-ray emission and absence of catalogued counterparts, both objects were recently targeted with the Large Binocular Telescope and the Southern African Large Telescope. The absence of counterparts down to deep optical limits (25 mag, 5$蟽$) and, as a result, large X-ray-to-optical flux ratios in both cases strongly suggest an INS nature. The X-ray spectra of both sources are well described by a simple absorbed blackbody, whereas other thermal and non-thermal models (e.g. a hot-plasma emission spectrum or power law) are disfavoured by the spectral analysis. Within the current observational limits, and as expected for cooling INSs, no significant variation ($>2蟽$) has been identified over the first two-year time span of the survey. Upcoming dedicated follow-up observations will help us to confirm the candidates' nature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.14066v1-abstract-full').style.display = 'none'; document.getElementById('2304.14066v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 8 figures, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 674, A155 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.07637">arXiv:2208.07637</a> <span> [<a href="https://arxiv.org/pdf/2208.07637">pdf</a>, <a href="https://arxiv.org/format/2208.07637">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244514">10.1051/0004-6361/202244514 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> XMM-Newton and SRG/eROSITA observations of the isolated neutron star candidate 4XMM J022141.5-735632 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Kurpas%2C+J">Jan Kurpas</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">Axel D. Schwope</a>, <a href="/search/?searchtype=author&query=Valdes%2C+F">Frank Valdes</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">Frank Haberl</a>, <a href="/search/?searchtype=author&query=Traulsen%2C+I">Iris Traulsen</a>, <a href="/search/?searchtype=author&query=Tubin%2C+D">Dusan Tubin</a>, <a href="/search/?searchtype=author&query=Becker%2C+W">Werner Becker</a>, <a href="/search/?searchtype=author&query=Comparat%2C+J">Johan Comparat</a>, <a href="/search/?searchtype=author&query=Maitra%2C+C">Chandreyee Maitra</a>, <a href="/search/?searchtype=author&query=Meisner%2C+A">Aaron Meisner</a>, <a href="/search/?searchtype=author&query=Moustakas%2C+J">John Moustakas</a>, <a href="/search/?searchtype=author&query=Salvato%2C+M">Mara Salvato</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.07637v1-abstract-short" style="display: inline;"> We report the results of follow-up investigations of a possible new thermally emitting isolated neutron star (INS), 4XMM J022141.5-735632, using observations from XMM-Newton and Spectrum Roentgen Gamma (SRG) eROSITA. The analysis is complemented by Legacy Survey imaging in the optical and near-infrared wavelengths. The X-ray source, the first to be targeted by XMM-Newton in an effort to identify n… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.07637v1-abstract-full').style.display = 'inline'; document.getElementById('2208.07637v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.07637v1-abstract-full" style="display: none;"> We report the results of follow-up investigations of a possible new thermally emitting isolated neutron star (INS), 4XMM J022141.5-735632, using observations from XMM-Newton and Spectrum Roentgen Gamma (SRG) eROSITA. The analysis is complemented by Legacy Survey imaging in the optical and near-infrared wavelengths. The X-ray source, the first to be targeted by XMM-Newton in an effort to identify new INS candidates from the fourth generation of the XMM-Newton serendipitous source catalogue Data Release 9 (4XMM-DR9), shows a remarkably soft energy distribution and a lack of catalogued counterparts; the very high X-ray-to-optical flux ratio virtually excludes any other identification than an INS. Within current observational limits, no significant flux variation nor change of spectral state is registered over nearly ten years. Future dedicated observations, particularly to search for pulsations, are crucial to shed further light on the nature of the X-ray source and relations to other Galactic neutron stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.07637v1-abstract-full').style.display = 'none'; document.getElementById('2208.07637v1-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 6 figures, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 666, A148 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.06793">arXiv:2202.06793</a> <span> [<a href="https://arxiv.org/pdf/2202.06793">pdf</a>, <a href="https://arxiv.org/format/2202.06793">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1017/S1743921322000333">10.1017/S1743921322000333 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Deep eROSITA observations of the "magnificent seven" isolated neutron stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana Mancini Pires</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">Axel Schwope</a>, <a href="/search/?searchtype=author&query=Kurpas%2C+J">Jan Kurpas</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="2202.06793v1-abstract-short" style="display: inline;"> We report the initial results of deep eROSITA monitoring of the "magnificent seven" isolated neutron stars (INSs). Thanks to a combination of high count statistics and good energy resolution, the eROSITA datasets unveil the increasingly complex energy distribution of these presumably simple thermal emitters. For three targets, we report the detection of multiple (in some cases, phase-dependent) sp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.06793v1-abstract-full').style.display = 'inline'; document.getElementById('2202.06793v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.06793v1-abstract-full" style="display: none;"> We report the initial results of deep eROSITA monitoring of the "magnificent seven" isolated neutron stars (INSs). Thanks to a combination of high count statistics and good energy resolution, the eROSITA datasets unveil the increasingly complex energy distribution of these presumably simple thermal emitters. For three targets, we report the detection of multiple (in some cases, phase-dependent) spectral absorption features and deviations from the dominant thermal continuum. Unexpected long-term changes of spectral state and timing behaviour have additionally been observed for two INSs. The results pose challenging theoretical questions on the nature of the variations and absorption features and ultimately impact the modeling of the atmosphere and cooling of highly magnetised neutron stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.06793v1-abstract-full').style.display = 'none'; document.getElementById('2202.06793v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">4 pages, 2 figures, to be published in the proceedings of IAU Symposium 363, Neutron Star Astrophysics at the Crossroads: Magnetars and the Multimessenger Revolution</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.06036">arXiv:2109.06036</a> <span> [<a href="https://arxiv.org/pdf/2109.06036">pdf</a>, <a href="https://arxiv.org/format/2109.06036">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1674-4527/21/11/294">10.1088/1674-4527/21/11/294 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> What causes the absence of pulsations in Central Compact Objects in Supernova Remnants? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Wu%2C+Q">Qi Wu</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">Axel Schwope</a>, <a href="/search/?searchtype=author&query=Xiao%2C+G">Guang-Cheng Xiao</a>, <a href="/search/?searchtype=author&query=Yan%2C+S">Shu-Ping Yan</a>, <a href="/search/?searchtype=author&query=Ji%2C+L">Li Ji</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="2109.06036v1-abstract-short" style="display: inline;"> Most young neutron stars belonging to the class of Central Compact Objects in supernova remnants (CCOs) do not have known periodicities. We investigated seven such CCOs to understand the common reasons for the absence of detected pulsations. Making use of XMM-Newton, Chandra, and NICER observations, we perform a systematic timing and spectral analysis to derive updated sensitivity limits for both… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.06036v1-abstract-full').style.display = 'inline'; document.getElementById('2109.06036v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.06036v1-abstract-full" style="display: none;"> Most young neutron stars belonging to the class of Central Compact Objects in supernova remnants (CCOs) do not have known periodicities. We investigated seven such CCOs to understand the common reasons for the absence of detected pulsations. Making use of XMM-Newton, Chandra, and NICER observations, we perform a systematic timing and spectral analysis to derive updated sensitivity limits for both periodic signals and multi-temperature spectral components that could be associated with radiation from hotspots on the neutron star surface. Based on these limits, we then investigated for each target the allowed viewing geometry that could explain the lack of pulsations. We estimate it is unlikely ($< 10^{-6}$) to attribute that we do not see pulsations to an unfavorable viewing geometry for five considered sources. Alternatively, the carbon atmosphere model, which assumes homogeneous temperature distribution on the surface, describes the spectra equally well and provides a reasonable interpretation for the absence of detected periodicities within current limits. The unusual properties of CCOs with respect to other young neutron stars could suggest a different evolutionary path, as that proposed for sources experiencing episodes of significant fallback accretion after the supernova event. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.06036v1-abstract-full').style.display = 'none'; document.getElementById('2109.06036v1-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 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">Accepted for publication in RAA; 16 pages, 2 figures, and 9 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.14533">arXiv:2106.14533</a> <span> [<a href="https://arxiv.org/pdf/2106.14533">pdf</a>, <a href="https://arxiv.org/format/2106.14533">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div 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/10.1051/0004-6361/202141105">10.1051/0004-6361/202141105 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Phase-resolved X-ray spectroscopy of PSR B0656+14 with SRG/eROSITA and XMM-Newton </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Schwope%2C+A">Axel Schwope</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Kurpas%2C+J">Jan Kurpas</a>, <a href="/search/?searchtype=author&query=Doroshenko%2C+V">Victor Doroshenko</a>, <a href="/search/?searchtype=author&query=Suleimanov%2C+V+F">Valery F. Suleimanov</a>, <a href="/search/?searchtype=author&query=Freyberg%2C+M">Michael Freyberg</a>, <a href="/search/?searchtype=author&query=Becker%2C+W">Werner Becker</a>, <a href="/search/?searchtype=author&query=Dennerl%2C+K">Konrad Dennerl</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">Frank Haberl</a>, <a href="/search/?searchtype=author&query=Lamer%2C+G">Georg Lamer</a>, <a href="/search/?searchtype=author&query=Maitra%2C+C">Chandreyee Maitra</a>, <a href="/search/?searchtype=author&query=Potekhin%2C+A+Y">Alexander Y. Potekhin</a>, <a href="/search/?searchtype=author&query=Ramos-Ceja%2C+M+E">Miriam E. Ramos-Ceja</a>, <a href="/search/?searchtype=author&query=Santangelo%2C+A">Andrea Santangelo</a>, <a href="/search/?searchtype=author&query=Traulsen%2C+I">Iris Traulsen</a>, <a href="/search/?searchtype=author&query=Werner%2C+K">Klaus Werner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.14533v1-abstract-short" style="display: inline;"> (abridged version) We present a detailed spectroscopic and timing analysis of X-ray observations of the bright radio-to-gamma-ray emitting pulsar PSR B0656+14, which were obtained simultaneously with eROSITA and XMM-Newton during the Calibration and Performance Verification phase of the Spektrum-Roentgen-Gamma mission (SRG) for 100 ks. Using XMM-Newton and NICER we firstly established an X-ray eph… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.14533v1-abstract-full').style.display = 'inline'; document.getElementById('2106.14533v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.14533v1-abstract-full" style="display: none;"> (abridged version) We present a detailed spectroscopic and timing analysis of X-ray observations of the bright radio-to-gamma-ray emitting pulsar PSR B0656+14, which were obtained simultaneously with eROSITA and XMM-Newton during the Calibration and Performance Verification phase of the Spektrum-Roentgen-Gamma mission (SRG) for 100 ks. Using XMM-Newton and NICER we firstly established an X-ray ephemeris for the time interval 2015 to 2020, which connects all X-ray observations in this period without cycle count alias and phase shifts. The mean eROSITA spectrum clearly reveals an absorption feature originating from the star at 570 eV with a Gaussian sigma of about 70 eV, tentatively identified earlier in a long XMM-Newton observation (Arumugasamy et al. 2018). A second absorption feature, described here as an absorption edge, occurs at 260-265 eV. It could be of atmospheric or of instrumental origin. These absorption features are superposed on various emission components, phenomenologically described as the sum of hot (120 eV) and cold (65 eV) blackbody components, both of photospheric origin, and a power-law with photon index Gamma=2. The phase-resolved spectroscopy reveals that the Gaussian absorption line at 570 eV is clearly present throughout ~60% of the spin cycle. The visibility of the line strength coincides in phase with the maximum flux of the hot blackbody. We also present three families of model atmospheres: a magnetised atmosphere, a condensed surface, and a mixed model, which were applied to the mean observed spectrum and whose continuum fit the observed data well. The atmosphere model, however, predicts too short distances. For the mixed model, the Gaussian absorption may be interpreted as proton cyclotron absorption in a field as high as 10^14 G, which is significantly higher than that derived from the moderate observed spin-down. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.14533v1-abstract-full').style.display = 'none'; document.getElementById('2106.14533v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to A&A for the Special Issue: The Early Data Release of eROSITA and Mikhail Pavlinsky ART-XC on the SRG Mission. 21 pages, 13 figures, 13 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 661, A41 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1902.04679">arXiv:1902.04679</a> <span> [<a href="https://arxiv.org/pdf/1902.04679">pdf</a>, <a href="https://arxiv.org/ps/1902.04679">ps</a>, <a href="https://arxiv.org/format/1902.04679">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Methodology">stat.ME</span> </div> </div> <p class="title is-5 mathjax"> High dimensionality: The latest challenge to data analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Branco%2C+J+A">J. A. Branco</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1902.04679v1-abstract-short" style="display: inline;"> The advent of modern technology, permitting the measurement of thousands of characteristics simultaneously, has given rise to floods of data characterized by many large or even huge datasets. This new paradigm presents extraordinary challenges to data analysis and the question arises: how can conventional data analysis methods, devised for moderate or small datasets, cope with the complexities of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.04679v1-abstract-full').style.display = 'inline'; document.getElementById('1902.04679v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.04679v1-abstract-full" style="display: none;"> The advent of modern technology, permitting the measurement of thousands of characteristics simultaneously, has given rise to floods of data characterized by many large or even huge datasets. This new paradigm presents extraordinary challenges to data analysis and the question arises: how can conventional data analysis methods, devised for moderate or small datasets, cope with the complexities of modern data? The case of high dimensional data is particularly revealing of some of the drawbacks. We look at the case where the number of characteristics measured in an object is at least the number of observed objects and conclude that this configuration leads to geometrical and mathematical oddities and is an insurmountable barrier for the direct application of traditional methodologies. If scientists are going to ignore fundamental mathematical results arrived at in this paper and blindly use software to analyze data, the results of their analyses may not be trustful, and the findings of their experiments may never be validated. That is why new methods together with the wise use of traditional approaches are essential to progress safely through the present reality. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.04679v1-abstract-full').style.display = 'none'; document.getElementById('1902.04679v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Keywords: Curse of dimensionality; High dimensional data; Mahalanobis distance</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1901.08533">arXiv:1901.08533</a> <span> [<a href="https://arxiv.org/pdf/1901.08533">pdf</a>, <a href="https://arxiv.org/format/1901.08533">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201834801">10.1051/0004-6361/201834801 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A deep XMM-Newton look on the thermally emitting isolated neutron star RX J1605.3+3249 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">Axel D. Schwope</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">Frank Haberl</a>, <a href="/search/?searchtype=author&query=Zavlin%2C+V+E">Vyacheslav E. Zavlin</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Zane%2C+S">Silvia Zane</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="1901.08533v1-abstract-short" style="display: inline;"> Previous XMM-Newton observations of the thermally emitting isolated neutron star RX J1605.3+3249 provided a candidate for a shallow periodic signal and evidence of a fast spin down, which suggested a high dipolar magnetic field and an evolution from a magnetar. We obtained a large programme with XMM-Newton to confirm its candidate timing solution, understand the energy-dependent amplitude of the m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.08533v1-abstract-full').style.display = 'inline'; document.getElementById('1901.08533v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1901.08533v1-abstract-full" style="display: none;"> Previous XMM-Newton observations of the thermally emitting isolated neutron star RX J1605.3+3249 provided a candidate for a shallow periodic signal and evidence of a fast spin down, which suggested a high dipolar magnetic field and an evolution from a magnetar. We obtained a large programme with XMM-Newton to confirm its candidate timing solution, understand the energy-dependent amplitude of the modulation, and investigate the spectral features of the source. We performed extensive high-resolution and broadband periodicity searches in the new observations, using the combined photons of the three EPIC cameras and allowing for moderate changes of pulsed fraction and the optimal energy range for detection. A deep $4蟽$ upper limit of $1.33(6)\%$ for modulations in the relevant frequency range conservatively rules out the candidate period previously reported. Blind searches revealed no other periodic signal above the $1.5\%$ level $(3蟽$) in any of the four new observations. While theoretical models fall short at physically describing the complex energy distribution of the source, best-fit X-ray spectral parameters are obtained for a fully or partially ionized neutron star hydrogen atmosphere model with $B=10^{13}$ G, modified by a broad Gaussian absorption line at $385\pm10$ eV. The deep limits from the timing analysis disfavour equally well-fit double temperature blackbody models where both the star surface and small hotspots contribute to the X-ray flux of the source. We identified a low significance ($1蟽$) temporal trend on the parameters of the source in the analysis of RGS data dating back to 2002, which may be explained by unaccounted calibration issues and spectral model uncertainties. The new dataset also shows no evidence of the previously reported narrow absorption feature at $\sim570$ eV, whose possible transient nature disfavours an atmospheric origin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.08533v1-abstract-full').style.display = 'none'; document.getElementById('1901.08533v1-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 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">15 pages, 6 figures, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 623, A73 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1711.05045">arXiv:1711.05045</a> <span> [<a href="https://arxiv.org/pdf/1711.05045">pdf</a>, <a href="https://arxiv.org/format/1711.05045">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The missing links of neutron star evolution in the eROSITA all-sky X-ray survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana Mancini Pires</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="1711.05045v1-abstract-short" style="display: inline;"> The observational manifestation of a neutron star is strongly connected with the properties of its magnetic field. During the star's lifetime, the field strength and its changes dominate the thermo-rotational evolution and the source phenomenology across the electromagnetic spectrum. Signatures of magnetic field evolution are best traced among elusive groups of X-ray emitting isolated neutron star… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.05045v1-abstract-full').style.display = 'inline'; document.getElementById('1711.05045v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.05045v1-abstract-full" style="display: none;"> The observational manifestation of a neutron star is strongly connected with the properties of its magnetic field. During the star's lifetime, the field strength and its changes dominate the thermo-rotational evolution and the source phenomenology across the electromagnetic spectrum. Signatures of magnetic field evolution are best traced among elusive groups of X-ray emitting isolated neutron stars (INSs), which are mostly quiet in the radio and $纬$-ray wavelengths. It is thus important to investigate and survey INSs in X-rays in the hope of discovering peculiar sources and the long-sought missing links that will help us to advance our understanding of neutron star evolution. The Extended R枚ntgen Survey with an Imaging Telescope Array (\eROS), the primary instrument on the forthcoming Spectrum-RG mission, will scan the X-ray sky with unprecedented sensitivity and resolution. The survey has thus the unique potential to unveil the X-ray faint end of the neutron star population and probe sources that cannot be assessed by standard pulsar surveys. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.05045v1-abstract-full').style.display = 'none'; document.getElementById('1711.05045v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">5 pages, 3 figures; to appear in the proceedings of "Physics of Neutron Stars 2017" eds. G.G. Pavlov, J.A. Pons, P.S. Shternin & D.G. Yakovlev</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1711.05038">arXiv:1711.05038</a> <span> [<a href="https://arxiv.org/pdf/1711.05038">pdf</a>, <a href="https://arxiv.org/ps/1711.05038">ps</a>, <a href="https://arxiv.org/format/1711.05038">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> What will eROSITA reveal among X-ray faint isolated neutron stars? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana Mancini Pires</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="1711.05038v1-abstract-short" style="display: inline;"> Since the discovery of the first radio pulsar fifty years ago, the population of neutron stars in our Galaxy has grown to over 2,600. A handful of these sources, exclusively seen in X-rays, show properties that are not observed in normal pulsars. Despite their scarcity, they are key to understanding aspects of the neutron star phenomenology and evolution. The forthcoming all-sky survey of eROSITA… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.05038v1-abstract-full').style.display = 'inline'; document.getElementById('1711.05038v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.05038v1-abstract-full" style="display: none;"> Since the discovery of the first radio pulsar fifty years ago, the population of neutron stars in our Galaxy has grown to over 2,600. A handful of these sources, exclusively seen in X-rays, show properties that are not observed in normal pulsars. Despite their scarcity, they are key to understanding aspects of the neutron star phenomenology and evolution. The forthcoming all-sky survey of eROSITA will unveil the X-ray faint end of the neutron star population at unprecedented sensitivity; therefore, it has the unique potential to constrain evolutionary models and advance our understanding of the sources that are especially silent in the radio and $纬$-ray regimes. In this contribution I discuss the expected role of eROSITA, and the challenges it will face, at probing the galactic neutron star population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.05038v1-abstract-full').style.display = 'none'; document.getElementById('1711.05038v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">4 pages, 3 figures, to appear in the proceedings of "IAUS 337: Pulsar Astrophysics - The Next 50 Years" eds: P. Weltevrede, B.B.P. Perera, L. Levin Preston & S. Sanidas</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1611.07723">arXiv:1611.07723</a> <span> [<a href="https://arxiv.org/pdf/1611.07723">pdf</a>, <a href="https://arxiv.org/format/1611.07723">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1002/asna.201713333">10.1002/asna.201713333 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Follow-up of isolated neutron star candidates from the eROSITA survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">Axel D. Schwope</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</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="1611.07723v1-abstract-short" style="display: inline;"> Peculiar groups of X-ray emitting isolated neutron stars, which include magnetars, the "Magnificent Seven", and central compact objects in supernova remnants, escape detection in standard pulsar surveys. Yet, they constitute a key element in understanding the neutron star evolution and phenomenology. Their use in population studies in the galactic scale has been hindered by the scarcity of their d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.07723v1-abstract-full').style.display = 'inline'; document.getElementById('1611.07723v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1611.07723v1-abstract-full" style="display: none;"> Peculiar groups of X-ray emitting isolated neutron stars, which include magnetars, the "Magnificent Seven", and central compact objects in supernova remnants, escape detection in standard pulsar surveys. Yet, they constitute a key element in understanding the neutron star evolution and phenomenology. Their use in population studies in the galactic scale has been hindered by the scarcity of their detection. The all-sky survey of eROSITA on-board the forthcoming Spectrum-RG mission has the unique potential to unveil the X-ray faint part of the population and constrain evolutionary models. To create a forecast for the four-year all-sky survey, we perform Monte Carlo simulations of a population synthesis model, where we follow the evolutionary tracks of thermally emitting neutron stars in the Milky Way and test their detectability. In this work, we discuss strategies for pinpointing the most promising candidates for follow-up observing campaigns using current and future facilities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.07723v1-abstract-full').style.display = 'none'; document.getElementById('1611.07723v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">6 pages, 6 figures; to appear in the proceedings of the "XMM-Newton: The Next Decade" Science Workshop; Astronomical Notes, in press</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1508.05246">arXiv:1508.05246</a> <span> [<a href="https://arxiv.org/pdf/1508.05246">pdf</a>, <a href="https://arxiv.org/ps/1508.05246">ps</a>, <a href="https://arxiv.org/format/1508.05246">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201526436">10.1051/0004-6361/201526436 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New XMM-Newton observation of the thermally emitting isolated neutron star 2XMM J104608.7-594306 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Turolla%2C+R">Roberto Turolla</a>, <a href="/search/?searchtype=author&query=Popov%2C+S+B">Sergei B. Popov</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A+D">Axel D. Schwope</a>, <a href="/search/?searchtype=author&query=Treves%2C+A">Aldo Treves</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="1508.05246v2-abstract-short" style="display: inline;"> The isolated neutron star (INS) 2XMM J104608.7-594306 is one of the only two to be discovered through their thermal emission since the ROSAT era. In a first dedicated XMM-Newton observation of the source, we found intriguing evidence of a very fast spin period. We re-observed 2XMM J104608.7-594306 with XMM-Newton to better characterise the spectral energy distribution of the source, confirm the ca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.05246v2-abstract-full').style.display = 'inline'; document.getElementById('1508.05246v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1508.05246v2-abstract-full" style="display: none;"> The isolated neutron star (INS) 2XMM J104608.7-594306 is one of the only two to be discovered through their thermal emission since the ROSAT era. In a first dedicated XMM-Newton observation of the source, we found intriguing evidence of a very fast spin period. We re-observed 2XMM J104608.7-594306 with XMM-Newton to better characterise the spectral energy distribution of the source, confirm the candidate spin period, and possibly constrain the pulsar spin-down. Statistically acceptable spectral fits and meaningful physical parameters for the source are only obtained when the purely thermal spectrum is modified by at least one line in absorption. The implied distance is consistent with a location in (or in front of) the Carina nebula, and radiation radii are compatible with emission originating on most of the surface. Non-thermal X-ray emission is ruled out at levels above 0.5% of the source luminosity. Unfortunately, the second XMM-Newton observation proved inconclusive in terms of confirming (discarding) the fast candidate spin, providing an upper limit on the pulsed fraction of the source that is very close to the limiting sensitivity for detecting the modulation found previously. In the absence of an unambiguous period determination and an estimate of the magnetic field, the nature of the source remains open to interpretation. Its likely association with the Carina cluster and its overall spectral properties (only shared by a handful of other peculiar INSs) disfavour a standard evolutionary path, or one in which the source was previously recycled by accretion in a binary system. The INS 2XMM J104608.7-594306 may be similar to Calvera (1RXS J141256.0+792204), a neutron star for which the scenario of an evolved `anti-magnetar' has been discussed. A better age estimate and deeper radio and gamma-ray limits are required to further constrain the evolutionary state of the neutron star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.05246v2-abstract-full').style.display = 'none'; document.getElementById('1508.05246v2-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 September, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 August, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">13 pages, 5 figures, accepted for publication in A&A (revised version after language editing; results unchanged)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 583, A117 (2015) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1401.7147">arXiv:1401.7147</a> <span> [<a href="https://arxiv.org/pdf/1401.7147">pdf</a>, <a href="https://arxiv.org/ps/1401.7147">ps</a>, <a href="https://arxiv.org/format/1401.7147">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201423380">10.1051/0004-6361/201423380 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> XMM-Newton reveals a candidate period for the spin of the "Magnificent Seven" neutron star RX J1605.3+3249 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">Frank Haberl</a>, <a href="/search/?searchtype=author&query=Zavlin%2C+V+E">Vyacheslav E. Zavlin</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Zane%2C+S">Silvia Zane</a>, <a href="/search/?searchtype=author&query=Hohle%2C+M+M">Markus M. Hohle</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="1401.7147v2-abstract-short" style="display: inline;"> The group of thermally emitting isolated neutron stars (INSs) known as the "Magnificent Seven" (M7) is unique among the various neutron star populations. Crustal heating by means of magnetic field decay and an evolutionary link with magnetars may explain why these objects rotate more slowly and have higher thermal luminosities and magnetic field intensities than standard pulsars of similar age. Th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1401.7147v2-abstract-full').style.display = 'inline'; document.getElementById('1401.7147v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1401.7147v2-abstract-full" style="display: none;"> The group of thermally emitting isolated neutron stars (INSs) known as the "Magnificent Seven" (M7) is unique among the various neutron star populations. Crustal heating by means of magnetic field decay and an evolutionary link with magnetars may explain why these objects rotate more slowly and have higher thermal luminosities and magnetic field intensities than standard pulsars of similar age. The third brightest INS, RX J1605.3+3249, is the only object amidst the seven still lacking a detected periodicity. We observed the source with the XMM-Newton Observatory for 60 ks aiming at unveiling the neutron star rotation rate and investigating its spectrum in detail. A periodic signal at P=3.387864(16) s, most likely the neutron star spin period, is detected at the 4-sigma confidence level. The coherent combination of the new data with a past XMM-Newton EPIC-pn observation of the source constrains the pulsar spin-down rate at the 2-sigma confidence level, implying a dipolar magnetic field of B~7.4e13 G. If confirmed, RX J1605.3+3249 would be the neutron star with the highest dipolar field amongst the M7. The spectrum of the source shows evidence of a cool blackbody component, as well as for the presence of two broad absorption features. Furthermore, high-resolution spectroscopy with the RGS cameras confirms the presence of a narrow absorption feature at energy 0.57 keV in the co-added spectrum of the source, also seen in other thermally emitting isolated neutron stars. Phase-resolved spectroscopy, as well as a dedicated observing campaign aimed at determining a timing solution, will give invaluable constraints on the neutron star geometry and will allow one to confirm the high value of spin down, which would place the source closer to a magnetar than any other M7 INS. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1401.7147v2-abstract-full').style.display = 'none'; document.getElementById('1401.7147v2-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> 29 January, 2014; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 January, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 6 figures; accepted for publication in A&A (revised version after language editing; results unchanged)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1312.0508">arXiv:1312.0508</a> <span> [<a href="https://arxiv.org/pdf/1312.0508">pdf</a>, <a href="https://arxiv.org/ps/1312.0508">ps</a>, <a href="https://arxiv.org/format/1312.0508">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </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/10.1051/0004-6361/201322662">10.1051/0004-6361/201322662 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> XMM-Newton observations of the low-luminosity cataclysmic variable V405 Pegasi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Schwope%2C+A+D">A. D. Schwope</a>, <a href="/search/?searchtype=author&query=Scipione%2C+V">V. Scipione</a>, <a href="/search/?searchtype=author&query=Traulsen%2C+I">I. Traulsen</a>, <a href="/search/?searchtype=author&query=Schwarz%2C+R">R. Schwarz</a>, <a href="/search/?searchtype=author&query=Granzer%2C+T">T. Granzer</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Thorstensen%2C+J+R">J. R. Thorstensen</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="1312.0508v1-abstract-short" style="display: inline;"> V405 Peg is a low-luminosity cataclysmic variable (CV) that was identified as the optical counterpart of the bright, high-latitude ROSAT all-sky survey source RBS1955. The system was suspected to belong to a largely undiscovered population of hibernating CVs. Despite intensive optical follow-up its subclass however remained undetermined. We want to further classify V405 Peg and understand its ro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1312.0508v1-abstract-full').style.display = 'inline'; document.getElementById('1312.0508v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1312.0508v1-abstract-full" style="display: none;"> V405 Peg is a low-luminosity cataclysmic variable (CV) that was identified as the optical counterpart of the bright, high-latitude ROSAT all-sky survey source RBS1955. The system was suspected to belong to a largely undiscovered population of hibernating CVs. Despite intensive optical follow-up its subclass however remained undetermined. We want to further classify V405 Peg and understand its role in the CV zoo via its long-term behaviour, spectral properties, energy distribution and accretion luminosity. We perform a spectral and timing analysis of \textit{XMM-Newton} X-ray and ultra-violet data. Archival WISE, HST, and Swift observations are used to determine the spectral energy distribution and characterize the long-term variability. The X-ray spectrum is characterized by emission from a multi-temperature plasma. No evidence for a luminous soft X-ray component was found. Orbital phase-dependent X-ray photometric variability by $\sim50\%$ occurred without significant spectral changes. No further periodicity was significant in our X-ray data. The average X-ray luminosity during the XMM-Newton observations was L_X, bol simeq 5e30 erg/s but, based on the Swift observations, the corresponding luminosity varied between 5e29 erg/s and 2e31 erg/son timescales of years. The CV subclass of this object remains elusive. The spectral and timing properties show commonalities with both classes of magnetic and non-magnetic CVs. The accretion luminosity is far below than that expected for a standard accreting CV at the given orbital period. Objects like V405 Peg might represent the tip of an iceberg and thus may be important contributors to the Galactic Ridge X-ray Emission. If so they will be uncovered by future X-ray surveys, e.g. with eROSITA. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1312.0508v1-abstract-full').style.display = 'none'; document.getElementById('1312.0508v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 December, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2013. </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">A&A, in press</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1206.3494">arXiv:1206.3494</a> <span> [<a href="https://arxiv.org/pdf/1206.3494">pdf</a>, <a href="https://arxiv.org/ps/1206.3494">ps</a>, <a href="https://arxiv.org/format/1206.3494">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Peculiar isolated neutron stars and the source in the Carina Nebula </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana Mancini Pires</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="1206.3494v1-abstract-short" style="display: inline;"> The new results of our observing campaign targeting the isolated neutron star 2XMM J104608.7-594306 in the Carina Nebula are used to understand how peculiar groups of isolated neutron stars relate to each other, as well as to the bulk of the normal radio pulsar population. </span> <span class="abstract-full has-text-grey-dark mathjax" id="1206.3494v1-abstract-full" style="display: none;"> The new results of our observing campaign targeting the isolated neutron star 2XMM J104608.7-594306 in the Carina Nebula are used to understand how peculiar groups of isolated neutron stars relate to each other, as well as to the bulk of the normal radio pulsar population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1206.3494v1-abstract-full').style.display = 'none'; document.getElementById('1206.3494v1-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 June, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">2 pages, 1 figure, proceedings of the conference "Electromagnetic Radiation from Pulsars and Magnetars", 24-27 April 2012, Zielona Gora, Poland</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1205.0427">arXiv:1205.0427</a> <span> [<a href="https://arxiv.org/pdf/1205.0427">pdf</a>, <a href="https://arxiv.org/ps/1205.0427">ps</a>, <a href="https://arxiv.org/format/1205.0427">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201219161">10.1051/0004-6361/201219161 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The peculiar isolated neutron star in the Carina Nebula - Deep XMM-Newton and ESO-VLT observations of 2XMM J104608.7-594306 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana Mancini Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Turolla%2C+R">Roberto Turolla</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">Axel Schwope</a>, <a href="/search/?searchtype=author&query=Pilia%2C+M">Maura Pilia</a>, <a href="/search/?searchtype=author&query=Treves%2C+A">Aldo Treves</a>, <a href="/search/?searchtype=author&query=Popov%2C+S+B">Sergei B. Popov</a>, <a href="/search/?searchtype=author&query=Janot-Pacheco%2C+E">Eduardo Janot-Pacheco</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="1205.0427v2-abstract-short" style="display: inline;"> While fewer in number than the dominant rotation-powered radio pulsar population, peculiar classes of isolated neutron stars (INSs) -- which include magnetars, the ROSAT-discovered "Magnificent Seven" (M7), rotating radio transients (RRATs), and central compact objects in supernova remnants (CCOs) -- represent a key element in understanding the neutron star phenomenology. We report the results of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1205.0427v2-abstract-full').style.display = 'inline'; document.getElementById('1205.0427v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1205.0427v2-abstract-full" style="display: none;"> While fewer in number than the dominant rotation-powered radio pulsar population, peculiar classes of isolated neutron stars (INSs) -- which include magnetars, the ROSAT-discovered "Magnificent Seven" (M7), rotating radio transients (RRATs), and central compact objects in supernova remnants (CCOs) -- represent a key element in understanding the neutron star phenomenology. We report the results of an observational campaign to study the properties of the source 2XMM J104608.7-594306. Its evolutionary state is investigated by means of deep dedicated observations obtained with XMM-Newton, the ESO Very Large Telescope, as well as publicly available gamma-ray data from the Fermi and AGILE missions. The observations confirm previous expectations and reveal a unique type of object. The source, which is likely within the Carina Nebula, has a soft spectrum with absorption features and no magnetospheric emission. The optical counterpart is fainter than V=27 and no gamma-ray emission is significantly detected. Very interestingly, while these characteristics are remarkably similar to those of the M7 or the only RRAT so far detected in X-rays, which all have spin periods of a few seconds, we found intriguing evidence of very rapid rotation, P=18.6 ms. We interpret these new results in the light of the observed properties of the currently known neutron star population, in particular those of standard rotation-powered pulsars, recycled objects, and CCOs. We find that none of these scenarios can satisfactorily explain the collective properties of 2XMM J104608.7-594306, although it may be related to the still poorly known class of Galactic anti-magnetars. Future XMM-Newton data, granted for the next cycle of observations (AO11), will help us to improve our current observational interpretation of the source, enabling us to significantly constrain the rate of pulsar spin down. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1205.0427v2-abstract-full').style.display = 'none'; document.getElementById('1205.0427v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 June, 2012; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 May, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">17 pages, 8 figures, accepted for publication in A&A (revised version after language editing; results unchanged)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astronomy & Astrophysics, Volume 544, id.A17 (2012) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1204.4096">arXiv:1204.4096</a> <span> [<a href="https://arxiv.org/pdf/1204.4096">pdf</a>, <a href="https://arxiv.org/ps/1204.4096">ps</a>, <a href="https://arxiv.org/format/1204.4096">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> <p class="title is-5 mathjax"> Image Analysis for Cosmology: Shape Measurement Challenge Review & Results from the Mapping Dark Matter Challenge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kitching%2C+T+D">T. D. Kitching</a>, <a href="/search/?searchtype=author&query=Rhodes%2C+J">J. Rhodes</a>, <a href="/search/?searchtype=author&query=Heymans%2C+C">C. Heymans</a>, <a href="/search/?searchtype=author&query=Massey%2C+R">R. Massey</a>, <a href="/search/?searchtype=author&query=Liu%2C+Q">Q. Liu</a>, <a href="/search/?searchtype=author&query=Cobzarenco%2C+M">M. Cobzarenco</a>, <a href="/search/?searchtype=author&query=Cragin%2C+B+L">B. L. Cragin</a>, <a href="/search/?searchtype=author&query=Hassaine%2C+A">A. Hassaine</a>, <a href="/search/?searchtype=author&query=Kirkby%2C+D">D. Kirkby</a>, <a href="/search/?searchtype=author&query=Lok%2C+E+J">E. Jin Lok</a>, <a href="/search/?searchtype=author&query=Margala%2C+D">D. Margala</a>, <a href="/search/?searchtype=author&query=Moser%2C+J">J. Moser</a>, <a href="/search/?searchtype=author&query=O%27Leary%2C+M">M. O'Leary</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Yurgenson%2C+S">S. Yurgenson</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="1204.4096v1-abstract-short" style="display: inline;"> In this paper we present results from the Mapping Dark Matter competition that expressed the weak lensing shape measurement task in its simplest form and as a result attracted over 700 submissions in 2 months and a factor of 3 improvement in shape measurement accuracy on high signal to noise galaxies, over previously published results, and a factor 10 improvement over methods tested on constant sh… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1204.4096v1-abstract-full').style.display = 'inline'; document.getElementById('1204.4096v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1204.4096v1-abstract-full" style="display: none;"> In this paper we present results from the Mapping Dark Matter competition that expressed the weak lensing shape measurement task in its simplest form and as a result attracted over 700 submissions in 2 months and a factor of 3 improvement in shape measurement accuracy on high signal to noise galaxies, over previously published results, and a factor 10 improvement over methods tested on constant shear blind simulations. We also review weak lensing shape measurement challenges, including the Shear TEsting Programmes (STEP1 and STEP2) and the GRavitational lEnsing Accuracy Testing competitions (GREAT08 and GREAT10). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1204.4096v1-abstract-full').style.display = 'none'; document.getElementById('1204.4096v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 April, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">20 pages, 12 figures. Solicited submission to New Astronomy Reviews</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1104.2975">arXiv:1104.2975</a> <span> [<a href="https://arxiv.org/pdf/1104.2975">pdf</a>, <a href="https://arxiv.org/ps/1104.2975">ps</a>, <a href="https://arxiv.org/format/1104.2975">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Methodology">stat.ME</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/10.1214/10-STS342">10.1214/10-STS342 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Statistical Model to Explain the Mendel--Fisher Controversy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Ana M. Pires</a>, <a href="/search/?searchtype=author&query=Branco%2C+J+A">Jo茫o A. Branco</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="1104.2975v1-abstract-short" style="display: inline;"> In 1866 Gregor Mendel published a seminal paper containing the foundations of modern genetics. In 1936 Ronald Fisher published a statistical analysis of Mendel's data concluding that "the data of most, if not all, of the experiments have been falsified so as to agree closely with Mendel's expectations." The accusation gave rise to a controversy which has reached the present time. There are reasona… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1104.2975v1-abstract-full').style.display = 'inline'; document.getElementById('1104.2975v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1104.2975v1-abstract-full" style="display: none;"> In 1866 Gregor Mendel published a seminal paper containing the foundations of modern genetics. In 1936 Ronald Fisher published a statistical analysis of Mendel's data concluding that "the data of most, if not all, of the experiments have been falsified so as to agree closely with Mendel's expectations." The accusation gave rise to a controversy which has reached the present time. There are reasonable grounds to assume that a certain unconscious bias was systematically introduced in Mendel's experimentation. Based on this assumption, a probability model that fits Mendel's data and does not offend Fisher's analysis is given. This reconciliation model may well be the end of the Mendel--Fisher controversy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1104.2975v1-abstract-full').style.display = 'none'; document.getElementById('1104.2975v1-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 April, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">Published in at http://dx.doi.org/10.1214/10-STS342 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> IMS-STS-STS342 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Statistical Science 2010, Vol. 25, No. 4, 545-565 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0906.4966">arXiv:0906.4966</a> <span> [<a href="https://arxiv.org/pdf/0906.4966">pdf</a>, <a href="https://arxiv.org/ps/0906.4966">ps</a>, <a href="https://arxiv.org/format/0906.4966">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div 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/10.1051/0004-6361/200912180">10.1051/0004-6361/200912180 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A search for thermally emitting isolated neutron stars in the 2XMMp catalogue </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</a>, <a href="/search/?searchtype=author&query=Janot-Pacheco%2C+E">Eduardo Janot-Pacheco</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="0906.4966v1-abstract-short" style="display: inline;"> The relatively large number of nearby radio-quiet and thermally emitting isolated neutron stars (INSs) discovered in the ROSAT All-Sky Survey, dubbed the ``Magnificent Seven'' (M7), suggests that they belong to a formerly neglected major component of the overall INS population. So far, attempts to discover similar INSs beyond the solar vicinity failed to confirm any reliable candidate. The EPIC… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0906.4966v1-abstract-full').style.display = 'inline'; document.getElementById('0906.4966v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0906.4966v1-abstract-full" style="display: none;"> The relatively large number of nearby radio-quiet and thermally emitting isolated neutron stars (INSs) discovered in the ROSAT All-Sky Survey, dubbed the ``Magnificent Seven'' (M7), suggests that they belong to a formerly neglected major component of the overall INS population. So far, attempts to discover similar INSs beyond the solar vicinity failed to confirm any reliable candidate. The EPIC cameras onboard the XMM-Newton satellite allow to efficiently search for new thermally emitting INSs. We used the 2XMMp catalogue to select sources with no catalogued candidate counterparts and with X-ray spectra similar to those of the M7, but seen at greater distances and thus undergoing higher interstellar absorptions. Identifications in more than 170 astronomical catalogues and visual screening allowed to select fewer than 30 good INS candidates. In order to rule out alternative identifications, we obtained deep ESO-VLT and SOAR optical imaging for the X-ray brightest candidates. We report here on the optical follow-up results of our search and discuss the possible nature of 8 of our candidates. A high X-ray-to-optical flux ratio together with a stable flux and soft X-ray spectrum make the brightest source of our sample, 2XMM J104608.7-594306, a newly discovered thermally emitting INS. The X-ray source 2XMM J010642.3+005032 has no evident optical counterpart and should be further investigated. The remaining X-ray sources are most probably identified with CVs and AGN, as inferred from the colours and flux ratios of their likely optical counterparts. Beyond the finding of new thermally emitting INSs, our study aims at constraining the space density of this Galactic population at great distances and at determining whether their apparently high density is a local anomaly or not. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0906.4966v1-abstract-full').style.display = 'none'; document.getElementById('0906.4966v1-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, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2009. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 5 figures, accepted for publication in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0901.1006">arXiv:0901.1006</a> <span> [<a href="https://arxiv.org/pdf/0901.1006">pdf</a>, <a href="https://arxiv.org/ps/0901.1006">ps</a>, <a href="https://arxiv.org/format/0901.1006">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div 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/10.1051/0004-6361/200811052">10.1051/0004-6361/200811052 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Proper motions of thermally emitting isolated neutron stars measured with Chandra </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Motch%2C+C">C. Motch</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">A. Schwope</a>, <a href="/search/?searchtype=author&query=Zavlin%2C+V+E">V. E. Zavlin</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="0901.1006v1-abstract-short" style="display: inline;"> The remarkable astrometric capabilities of Chandra offer the possibility to measure proper motions of X-ray sources with an unprecedented accuracy in this wavelength range. We recently completed a proper motion survey of three of the seven thermally emitting radio-quiet isolated neutron stars (INSs) discovered in the ROSAT all-sky survey. These INSs (RX J0420.0-5022, RX J0806.4-4123, and RX J130… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0901.1006v1-abstract-full').style.display = 'inline'; document.getElementById('0901.1006v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0901.1006v1-abstract-full" style="display: none;"> The remarkable astrometric capabilities of Chandra offer the possibility to measure proper motions of X-ray sources with an unprecedented accuracy in this wavelength range. We recently completed a proper motion survey of three of the seven thermally emitting radio-quiet isolated neutron stars (INSs) discovered in the ROSAT all-sky survey. These INSs (RX J0420.0-5022, RX J0806.4-4123, and RX J1308.6+2127) either lack an optical counterpart or have one so faint that ground based or space born optical observations push the current possibilities of the instrumentation to the limit. Pairs of ACIS observations were acquired 3 to 5 years apart to measure the displacement of the sources on the X-ray sky using as reference the background of extragalactic or remote Galactic X-ray sources. We derive 2 sigma upper limits of 123 mas/yr and 86 mas/yr on the proper motion of RX J0420.0-5022 and RX J0806.4-4123, respectively. RX J1308.6+2127 exhibits a very significant displacement (~ 9 sigma) yielding mu = 220 +/- 25 mas/yr, the second fastest measured among all ROSAT discovered INSs. The source is probably moving away rapidly from the Galactic plane at a speed which precludes any significant accretion of matter from the interstellar medium. Its transverse velocity of ~ 740 (d/700pc) km/s might be the largest of all ROSAT INSs and its corresponding spatial velocity stands among the fastest recorded for neutron stars. RX J1308.6+2127 is thus a middle-aged (age ~ 1 My) high velocity cooling neutron star. We investigate its possible origin in nearby OB associations or from a field OB star. In most cases, the flight time from birth place appears significantly shorter than the characteristic age derived from spin down rate. The distribution in transverse velocity of ROSAT INSs is not statistically different from that of normal radio pulsars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0901.1006v1-abstract-full').style.display = 'none'; document.getElementById('0901.1006v1-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 January, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2009. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 5 figures, accepted for publication in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0812.4151">arXiv:0812.4151</a> <span> [<a href="https://arxiv.org/pdf/0812.4151">pdf</a>, <a href="https://arxiv.org/ps/0812.4151">ps</a>, <a href="https://arxiv.org/format/0812.4151">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1051/0004-6361/200810966">10.1051/0004-6361/200810966 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The isolated neutron star candidate 2XMM J104608.7-594306 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">C. Motch</a>, <a href="/search/?searchtype=author&query=Turolla%2C+R">R. Turolla</a>, <a href="/search/?searchtype=author&query=Treves%2C+A">A. Treves</a>, <a href="/search/?searchtype=author&query=Popov%2C+S+B">S. B. Popov</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="0812.4151v2-abstract-short" style="display: inline;"> Over the last decade, X-ray observations unveiled the existence of several classes of isolated neutron stars (INSs) which are radio-quiet or exhibit radio emission with properties much at variance with those of ordinary radio pulsars. The identification of new sources is crucial in order to understand the relations among the different classes and to compare observational constraints with theoret… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0812.4151v2-abstract-full').style.display = 'inline'; document.getElementById('0812.4151v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0812.4151v2-abstract-full" style="display: none;"> Over the last decade, X-ray observations unveiled the existence of several classes of isolated neutron stars (INSs) which are radio-quiet or exhibit radio emission with properties much at variance with those of ordinary radio pulsars. The identification of new sources is crucial in order to understand the relations among the different classes and to compare observational constraints with theoretical expectations. A recent analysis of the 2XMMp catalogue provided less than 30 new thermally emitting INS candidates. Among these, the source 2XMM J104608.7-594306 appears particularly interesting because of the softness of its X-ray spectrum and of the present upper limits in the optical, which imply a logarithmic X-ray-to-optical flux ratio greater than 3.1, corrected for absorption. We present the X-ray and optical properties of 2XMM J104608.7-594306 and discuss its nature in the light of two possible scenarios invoked to explain the X-ray thermal emission from INSs: the release of residual heat in a cooling neutron star, as in the seven radio-quiet ROSAT-discovered INSs, and accretion from the interstellar medium. We find that the present observational picture of 2XMM J104608.7-594306 is consistent with a distant cooling INS with properties in agreement with the most up-to-date expectations of population synthesis models: it is fainter, hotter and more absorbed than the seven ROSAT sources and possibly located in the Carina Nebula, a region likely to harbour unidentified cooling neutron stars. The accretion scenario, although not entirely ruled out by observations, would require a very slow (~10 km/s) INS accreting at the Bondi-Hoyle rate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0812.4151v2-abstract-full').style.display = 'none'; document.getElementById('0812.4151v2-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 February, 2009; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 December, 2008; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2008. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 4 figures, accepted for publication in A&A (no changes relative to v1)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0712.0342">arXiv:0712.0342</a> <span> [<a href="https://arxiv.org/pdf/0712.0342">pdf</a>, <a href="https://arxiv.org/ps/0712.0342">ps</a>, <a href="https://arxiv.org/format/0712.0342">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1063/1.2900182">10.1063/1.2900182 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Proper motions of ROSAT discovered isolated neutron stars measured with Chandra: First X-ray measurement of the large proper motion of RX J1308.6+2127/RBS 1223 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Motch%2C+C">C. Motch</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">A. Schwope</a>, <a href="/search/?searchtype=author&query=Zavlin%2C+V+E">V. E. Zavlin</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="0712.0342v1-abstract-short" style="display: inline;"> The unprecedented spatial resolution of the Chandra observatory opens the possibility to detect with relatively high accuracy proper motions at X-ray wavelengths. We have conducted an astrometric study of three of the "Magnificent Seven", the thermally emitting radio quiet isolated neutron stars (INSs) discovered by ROSAT. These three INSs (RX J0420.0-5022, RX J0806.4-4123 and RX J1308.6+2127/RB… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0712.0342v1-abstract-full').style.display = 'inline'; document.getElementById('0712.0342v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0712.0342v1-abstract-full" style="display: none;"> The unprecedented spatial resolution of the Chandra observatory opens the possibility to detect with relatively high accuracy proper motions at X-ray wavelengths. We have conducted an astrometric study of three of the "Magnificent Seven", the thermally emitting radio quiet isolated neutron stars (INSs) discovered by ROSAT. These three INSs (RX J0420.0-5022, RX J0806.4-4123 and RX J1308.6+2127/RBS 1223) either lack an optical counterpart or have one too faint to be used for astrometric purposes. We obtained ACIS observations 3 to 5 years apart to constrain or measure the displacement of the sources on the X-ray sky using as reference the background of extragalactic or remote galactic X-ray sources. Upper limits of 138 mas/yr and 76 mas/yr on the proper motion of RX J0420.0-5022 and RX J0806.4-4123, respectively, have already been presented in Motch et al. (2007). Here we report the very significant measurement (~ 10 sigma) of the proper motion of the third INS of our program, RX J1308.6+2127/RBS1223. Comparing observations obtained in 2002 and 2007 reveals a displacement of 1.1 arcsec implying a yearly proper motion of 223 mas, the second fastest measured for the ROSAT discovered INSs. The source is rapidly moving away from the galactic plane at a speed which precludes any significant accretion of matter from the interstellar medium. Its transverse velocity of ~ 740 (d/700pc) km/s might be the largest of the "Magnificent Seven" and among the fastest recorded for neutron stars. RX J1308.6+2127/RBS1223 is thus a young high velocity cooling neutron star. The source may have its origin in the closest part of the Scutum OB2 association about 0.8 Myr ago, an age consistent with that expected from cooling curves, but significantly younger than inferred from pulse timing measurements (1.5 Myr). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0712.0342v1-abstract-full').style.display = 'none'; document.getElementById('0712.0342v1-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 December, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2007. </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">3 pages, 2 figures, proceedings of the conference "40 Years of Pulsars", 12-17 August 2007, Montreal, Canada</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> AIPConf.Proc.983:354-356,2008 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0710.5192">arXiv:0710.5192</a> <span> [<a href="https://arxiv.org/pdf/0710.5192">pdf</a>, <a href="https://arxiv.org/ps/0710.5192">ps</a>, <a href="https://arxiv.org/format/0710.5192">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1063/1.2900234">10.1063/1.2900234 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Searching for new thermally emitting isolated neutron stars in the 2XMMp catalogue - Discovery of a promising candidate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pires%2C+A+M">Adriana M. Pires</a>, <a href="/search/?searchtype=author&query=Motch%2C+C">Christian Motch</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="0710.5192v1-abstract-short" style="display: inline;"> The group of 7 thermally emitting and radio-quiet isolated neutron stars (INSs) discovered by ROSAT constitutes a nearby population which locally appears to be as numerous as that of the classical radio pulsars. So far, attempts to enlarge this particular group of INSs finding more remote objects failed to confirm any candidate. We found in the 2XMMp catalogue a handful of sources with no catalo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0710.5192v1-abstract-full').style.display = 'inline'; document.getElementById('0710.5192v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0710.5192v1-abstract-full" style="display: none;"> The group of 7 thermally emitting and radio-quiet isolated neutron stars (INSs) discovered by ROSAT constitutes a nearby population which locally appears to be as numerous as that of the classical radio pulsars. So far, attempts to enlarge this particular group of INSs finding more remote objects failed to confirm any candidate. We found in the 2XMMp catalogue a handful of sources with no catalogued counterparts and with X-ray spectra similar to those of the ROSAT discovered INSs, but seen at larger distances and thus undergoing higher interstellar absorptions. In order to rule out alternative identifications such as an AGN or a CV, we obtained deep ESO-VLT and SOAR optical imaging for the X-ray brightest candidates. We report here on the current status of our search and discuss the possible nature of our candidates. We focus particularly on the X-ray brightest source of our sample, 2XMM J104608.7-594306, observed serendipitously over more than four years by the XMM-Newton Observatory. A lower limit on the X-ray to optical flux ratio of ~ 300 together with a stable flux and soft X-ray spectrum make it the most promising thermally emitting INS candidate. Beyond the finding of new members, our study aims at constraining the space density of this population at large distances and at determining whether their apparently high local density is an anomaly or not. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0710.5192v1-abstract-full').style.display = 'none'; document.getElementById('0710.5192v1-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 October, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2007. </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">3 pages, 2 figures, proceedings of the conference "40 Years of Pulsars", 12-17 August 2007, Montreal, Canada</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> AIPConf.Proc.983:363-365,2008 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0608589">arXiv:astro-ph/0608589</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0608589">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0608589">ps</a>, <a href="https://arxiv.org/format/astro-ph/0608589">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/s10509-007-9338-6">10.1007/s10509-007-9338-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measuring proper motions of isolated neutron stars with Chandra </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Motch%2C+C">C. Motch</a>, <a href="/search/?searchtype=author&query=Pires%2C+A+M">A. M. Pires</a>, <a href="/search/?searchtype=author&query=Haberl%2C+F">F. Haberl</a>, <a href="/search/?searchtype=author&query=Schwope%2C+A">A. Schwope</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="astro-ph/0608589v1-abstract-short" style="display: inline;"> The excellent spatial resolution of the Chandra observatory offers the unprecedented possibility to measure proper motions at X-ray wavelength with relatively high accuracy using as reference the background of extragalactic or remote galactic X-ray sources. We took advantage of this capability to constrain the proper motion of RX J0806.4-4123 and RX J0420.0-5022, two X-ray bright and radio quiet… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0608589v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0608589v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0608589v1-abstract-full" style="display: none;"> The excellent spatial resolution of the Chandra observatory offers the unprecedented possibility to measure proper motions at X-ray wavelength with relatively high accuracy using as reference the background of extragalactic or remote galactic X-ray sources. We took advantage of this capability to constrain the proper motion of RX J0806.4-4123 and RX J0420.0-5022, two X-ray bright and radio quiet isolated neutron stars (INSs) discovered by ROSAT and lacking an optical counterpart. In this paper, we present results from a preliminary analysis from which we derive 2 sigma upper limits of 76 mas/yr and 138 mas/yr on the proper motions of RX J0806.4-4123 and RX J0420.0-5022 respectively. We use these values together with those of other ROSAT discovered INSs to constrain the origin, distance and evolutionary status of this particular group of objects. We find that the tangential velocities of radio quiet ROSAT neutron stars are probably consistent with those of 'normal' pulsars. Their distribution on the sky and, for those having accurate proper motion vectors, their possible birth places, all point to a local population, probably created in the part of the Gould Belt nearest to the earth. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0608589v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0608589v1-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 August, 2006; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2006. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 3 figures, to appear in Astrophysics and Space Science, in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface", edited by D. Page, R. Turolla and S. Zane</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.SpaceSci.308:217-224,2007 </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/license/index.html">Copyright</a></li> <li><a href="https://info.arxiv.org/help/policies/privacy_policy.html">Privacy Policy</a></li> </ul> </div> <div class="column sorry-app-links"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/web_accessibility.html">Web Accessibility Assistance</a></li> <li> <p class="help"> <a class="a11y-main-link" href="https://status.arxiv.org" target="_blank">arXiv Operational Status <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 512" class="icon filter-dark_grey" role="presentation"><path d="M224.3 273l-136 136c-9.4 9.4-24.6 9.4-33.9 0l-22.6-22.6c-9.4-9.4-9.4-24.6 0-33.9l96.4-96.4-96.4-96.4c-9.4-9.4-9.4-24.6 0-33.9L54.3 103c9.4-9.4 24.6-9.4 33.9 0l136 136c9.5 9.4 9.5 24.6.1 34z"/></svg></a><br> Get status notifications via <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/email/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg>email</a> or <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/slack/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="icon filter-black" role="presentation"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg>slack</a> </p> </li> </ul> </div> </div> </div>  </div> </footer> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/member_acknowledgement.js"></script> </body> </html>

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