<?xml-stylesheet href='/static/xsl/oai.xsl' type='text/xsl'?>
<ri:Resource created="2021-03-01T12:42:57Z" status="active" updated="2025-06-13T15:25:00Z" version="1.2" xmlns:cs="http://www.ivoa.net/xml/ConeSearch/v1.0" xmlns:ri="http://www.ivoa.net/xml/RegistryInterface/v1.0" xmlns:vr="http://www.ivoa.net/xml/VOResource/v1.0" xmlns:vs="http://www.ivoa.net/xml/VODataService/v1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ivoa.net/xml/ConeSearch/v1.0 http://vo.ari.uni-heidelberg.de/docs/schemata/ConeSearch.xsd http://www.ivoa.net/xml/VOResource/v1.0 http://vo.ari.uni-heidelberg.de/docs/schemata/VOResource.xsd http://www.ivoa.net/xml/VODataService/v1.1 http://vo.ari.uni-heidelberg.de/docs/schemata/VODataService.xsd" xsi:type="vs:CatalogService"><title>AstroSat/UVIT and Chandra X-ray sources in M31</title><shortName>J/ApJS/250/23</shortName><identifier>ivo://CDS.VizieR/J/ApJS/250/23</identifier><altIdentifier>doi:10.26093/cds/vizier.22500023</altIdentifier><curation><publisher ivo-id="ivo://CDS">CDS</publisher><creator><name>Leahy D.A.</name></creator><creator><name>Chen Y.</name></creator><date role="Updated">2021-09-10T14:35:25Z</date><date role="Created">2021-03-01T12:42:57Z</date><contact><name>CDS support team</name><address>CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France</address><email>cds-question@unistra.fr</email></contact></curation><content><subject>galaxies</subject><subject>x-ray-sources</subject><subject>ultraviolet-photometry</subject><subject>extinction</subject><subject>globular-star-clusters</subject><subject>x-ray-binary-stars</subject><description>An ultraviolet (UV) survey of M31 has been carried out during 2017-19 with the Ultra-Violet Imaging Telescope (UVIT) instrument on board the AstroSat Observatory. Here we match the M31 UVIT source catalog with the Chandra source catalog. We find 67 UVIT/Chandra sources detected in a varying number of UV and X-ray bands. The UV and X-ray photometry is analyzed using power-law and blackbody models. The X-ray types include 15 low-mass X-ray binaries (LMXBs) and five active galactic nuclei. Crossmatches with catalogs of stars, clusters, and other source types yield the following: 20 of the UVIT/Chandra sources match with M31 globular clusters, and nine with foreground stars. Three more globular clusters and two more foreground stars are consistent with the UVIT source positions although outside the Chandra match radius of 1". The UV emission of the UVIT/Chandra sources associated with globular clusters is consistent with emission from blue horizontal branch stars rather than from the X-ray source. The LMXBs in globular clusters are among the most luminous globular clusters in M31. Comparison with stellar evolutionary tracks shows that the UVIT/Chandra sources with high UV blackbody temperatures are consistent with massive (10-30M_{sun}_) stars in M31.</description><source format="bibcode">2020ApJS..250...23L</source><referenceURL>https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/250/23</referenceURL><type>Catalog</type><contentLevel>Research</contentLevel><relationship><relationshipType>IsServedBy</relationshipType><relatedResource ivo-id="ivo://CDS.VizieR/TAP">TAP VizieR generic service</relatedResource></relationship><relationship><relationshipType>IsServedBy</relationshipType><relatedResource>Conesearch service</relatedResource></relationship><relationship><relationshipType>related-to</relationshipType><relatedResource ivo-id="ivo://CDS.VizieR/B/chandra">B/chandra : The Chandra Archive Log (CXC, 1999-2014)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/I/345">I/345 : Gaia DR2 (Gaia Collaboration, 2018)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/I/347">I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/ApJ/663/320">J/ApJ/663/320 : IR-through-UV extinction curve (Fitzpatrick+, 2007)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/A+A/534/A55">J/A+A/534/A55 : Deep XMM-Newton Survey of M31 (Stiele+, 2011)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/ApJ/802/127">J/ApJ/802/127 : PHAT stellar cluster survey. II. AP catalog (Johnson+, 2015)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/other/RAA/15.1438">J/other/RAA/15.1438 : LAMOST new QSOs in M31 and M33 vicinity (Huo+, 2015)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/ApJ/824/42">J/ApJ/824/42 : Star clusters in M31. VII. GCs velocities (Caldwell+, 2016)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/ApJ/829/116">J/ApJ/829/116 : H-band spectroscopy of 25 bright M31 GCs (Sakari+, 2016)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/MNRAS/461/3443">J/MNRAS/461/3443 : M31 deepest Chandra catalog of point sources (Vulic+, 2016)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/A+A/620/A28">J/A+A/620/A28 : XMM northern disc of M31 sources (Sasaki+, 2018)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/ApJS/239/13">J/ApJS/239/13 : Chandra PHAT X-ray catalog of the M31 disk (Williams+, 2018)</relatedResource><relatedResource ivo-id="ivo://CDS.VizieR/J/ApJS/247/47">J/ApJS/247/47 : Ultraviolet survey of M31 with UVIT on AstroSat (Leahy+, 2020)</relatedResource></relationship></content><rights>https://cds.unistra.fr/vizier-org/licences_vizier.html</rights><capability><interface xsi:type="vr:WebBrowser"><accessURL use="full">https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/250/23</accessURL><mirrorURL title="VizieR at IUCAA: Pune, India">https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/250/23</mirrorURL><mirrorURL title="VizieR at SAAO: SAAO, South Africa">http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/250/23</mirrorURL></interface></capability><capability><interface xsi:type="vs:ParamHTTP"><accessURL use="base">https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/250/23</accessURL><mirrorURL title="VizieR at IUCAA: Pune, India">https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/250/23</mirrorURL><mirrorURL title="VizieR at SAAO: SAAO, South Africa">http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/250/23</mirrorURL><queryType>GET</queryType><resultType>text/xml+votable</resultType></interface></capability><capability standardID="ivo://ivoa.net/std/TAP#aux"><interface xsi:type="vs:ParamHTTP" role="std"><accessURL use="base">https://tapvizier.cds.unistra.fr/TAPVizieR/tap</accessURL></interface></capability><capability xsi:type="cs:ConeSearch" standardID="ivo://ivoa.net/std/ConeSearch"><description>Cone search capability for table J/ApJS/250/23/table1 (AstroSat/UVIT sources matched with Chandra sources and power law indices)</description><interface xsi:type="vs:ParamHTTP" role="std"><accessURL use="base">https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/250/23/table1?</accessURL><mirrorURL title="VizieR at IUCAA: Pune, India">https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/250/23/table1?</mirrorURL><mirrorURL title="VizieR at SAAO: SAAO, South Africa">http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/250/23/table1?</mirrorURL><queryType>GET</queryType><resultType>text/xml+votable</resultType></interface><maxSR>180.0</maxSR><maxRecords>50000</maxRecords><verbosity>true</verbosity><testQuery><ra>10.935875</ra><dec>41.40275</dec><sr>0.005555555555555556</sr></testQuery></capability><coverage><spatial>6/2622 2623 2666 2705 2708 2709</spatial><spectral>7.013462727736068e-19 1.5339351055263043e-18</spectral><footprint ivo-id="ivo://ivoa.net/std/moc">https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/250/23?format=ascii</footprint><waveband>X-ray</waveband><waveband>UV</waveband></coverage><tableset><schema><name>default</name><table><name>J/ApJS/250/23/table1</name><description>AstroSat/UVIT sources matched with Chandra sources and power law indices</description><column><name>recno</name><description>Record number assigned by the VizieR team. Should Not be used for identification.</description><ucd>meta.record</ucd><dataType xsi:type="vs:VOTableType">int</dataType></column><column><name>Seq</name><description>[1/67] Source running number</description><ucd>meta.id</ucd><dataType xsi:type="vs:VOTableType">int</dataType><flag>primary</flag></column><column><name>CXOU</name><description>CXOU name (HHMMSS.ss+DDMMSS.s; J2000; &lt;CXOU JHHMMSS.s+DDMMSS&gt; in Simbad)</description><ucd>meta.id;meta.main</ucd><dataType xsi:type="vs:VOTableType" arraysize="18*">char</dataType></column><column><name>RAdeg</name><description>[9.59/11.58] Right Ascension (J2000)</description><unit>deg</unit><ucd>pos.eq.ra</ucd></column><column><name>DEdeg</name><description>[40.21/41.72] Declination (J2000)</description><unit>deg</unit><ucd>pos.eq.dec</ucd></column><column><name>F148Wmag</name><description>[19.3/24.3]? Astrosat/UVIT F148W filter AB magnitude</description><unit>mag</unit><ucd>phot.mag;em.UV.100-200nm</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_F148Wmag</name><description>[0.05/0.4]? 1{sigma} uncertainty in F148Wmag</description><unit>mag</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>n_F148Wmag</name><description>[e] Flag on F148Wmag (5)</description><ucd>meta.note</ucd><dataType xsi:type="vs:VOTableType" arraysize="1*">char</dataType></column><column><name>F169Mmag</name><description>[21.1/22.2]? Astrosat/UVIT F169M filter AB magnitude</description><unit>mag</unit><ucd>phot.mag;em.UV.100-200nm</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_F169Mmag</name><description>[0.09/0.2]? The 1{sigma} uncertainty in F169Mmag</description><unit>mag</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>F172Mmag</name><description>[18.8/22.7]? Astrosat/UVIT F172M filter AB magnitude</description><unit>mag</unit><ucd>phot.mag;em.UV.100-200nm</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_F172Mmag</name><description>[0.07/0.4]? The 1{sigma} uncertainty in F172Mmag</description><unit>mag</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>N219Mmag</name><description>[16.6/22.5]? Astrosat/UVIT N219M filter AB magnitude</description><unit>mag</unit><ucd>phot.mag;em.UV.200-300nm</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_N219Mmag</name><description>[0.04/0.3]? The 1{sigma} uncertainty in N219Mmag</description><unit>mag</unit><ucd>stat.error;phot.mag</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>n_N219Mmag</name><description>[e] Flag on N219Mmag (5)</description><ucd>meta.note</ucd><dataType xsi:type="vs:VOTableType" arraysize="1*">char</dataType></column><column><name>N279Nmag</name><description>[15.18/22]? Astrosat/UVIT N279N filter AB magnitude</description><unit>mag</unit><ucd>phot.mag;em.UV.200-300nm</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_N279Nmag</name><description>[0.03/0.4]? The 1{sigma} uncertainty in N279Nmag</description><unit>mag</unit><ucd>stat.error;phot.mag</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>n_N279Nmag</name><description>[e] Flag on N279Nmag (5)</description><ucd>meta.note</ucd><dataType xsi:type="vs:VOTableType" arraysize="1*">char</dataType></column><column><name>Filter</name><description>Filters with match separation between 1-2" (1)</description><ucd>meta.code;instr.filter</ucd><dataType xsi:type="vs:VOTableType" arraysize="10*">char</dataType></column><column><name>XInd</name><description>[-1.5/5.4]? X-ray spectral index (2)</description><ucd>spect.index</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>E_XInd</name><description>[0.01/6.7]? Upper 90% uncertainty in XInd</description><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_XInd</name><description>[0.01/2.7]? Lower 90% uncertainty in XInd</description><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>U-XInd</name><description>[0.7/2.6]? UV-to-X-ray spectral index (3)</description><ucd>spect.index</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>E_U-XInd</name><description>[0.01/0.6]? Upper uncertainty in U-XInd</description><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_U-XInd</name><description>[0.01/0.2]? Lower uncertainty in U-XInd</description><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>Class</name><description>X-ray class (4)</description><ucd>meta.code.class</ucd><dataType xsi:type="vs:VOTableType" arraysize="13*">char</dataType></column><column><name>Opt</name><description>Optical counterpart (5)</description><ucd>meta.code.class</ucd><dataType xsi:type="vs:VOTableType" arraysize="11*">char</dataType></column><column><name>Fit</name><description>Display the Blackbody (BB) and power-law (PL) fits to UVIT photometry (link to Table 2)</description><ucd>meta.ref.url</ucd><dataType xsi:type="vs:VOTableType" arraysize="1*">char</dataType></column><column><name>L20</name><description>Display data from Leahy+, 2020, J/ApJS/247/47, within 3"</description><ucd>meta.ref.url</ucd><dataType xsi:type="vs:VOTableType" arraysize="*">char</dataType></column><column><name>_RA</name><description>Right ascension (derived from CXOU) for Eq=J2000</description><unit>deg</unit><ucd>pos.eq.ra;meta.main</ucd></column><column><name>_DE</name><description>Declination (derived from CXOU) for Eq=J2000</description><unit>deg</unit><ucd>pos.eq.dec;meta.main</ucd></column></table><table><name>J/ApJS/250/23/table2</name><description>Blackbody (BB) and power-law (PL) fits to UVIT photometry</description><column><name>BBChi2</name><description>[0/95] Chi-square of BB fit</description><ucd>stat.fit.param;meta.modelled</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>recno</name><description>Record number assigned by the VizieR team. Should Not be used for identification.</description><ucd>meta.record</ucd><dataType xsi:type="vs:VOTableType">int</dataType></column><column><name>Seq</name><description>[2/60] Source number</description><ucd>meta.id</ucd><dataType xsi:type="vs:VOTableType">int</dataType></column><column><name>fg</name><description>Identified as foreground star (1)</description><ucd>meta.code</ucd><dataType xsi:type="vs:VOTableType" arraysize="3*">char</dataType></column><column><name>CXOU</name><description>CXOU name (HHMMSS.ss+DDMMSS.s; J2000)</description><ucd>meta.id;meta.main</ucd><dataType xsi:type="vs:VOTableType" arraysize="18*">char</dataType></column><column><name>Filter</name><description>UVIT filters with a detected magnitude (2)</description><ucd>meta.code;instr.filter</ucd><dataType xsi:type="vs:VOTableType" arraysize="14*">char</dataType></column><column><name>BBAv</name><description>[0/1.83] Foreground extinction from BB fit (3)</description><unit>mag</unit><ucd>phys.absorption</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>E_BBAv</name><description>[0.01/0.2]? 90% upper error in BBAv</description><unit>mag</unit><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_BBAv</name><description>[0.02/0.2]? 90% lower error in BBAv</description><unit>mag</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>BBRad</name><description>[0.0069/466] Radius from BB fit (4)</description><unit>solRad</unit><ucd>phys.size.radius</ucd><dataType xsi:type="vs:VOTableType">double</dataType></column><column><name>E_BBRad</name><description>[0.0001/31] 90% upper error in BBRad</description><unit>solRad</unit><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">double</dataType></column><column><name>e_BBRad</name><description>[8e-5/28] 90% lower error in BBRad</description><unit>solRad</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">double</dataType></column><column><name>BBTeff</name><description>[5.4/26.3] Effective temperature from BB fit</description><unit>1000K</unit><ucd>phys.temperature.effective</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>E_BBTeff</name><description>[0.03/1.5] 90% upper error in BBTeff</description><unit>1000K</unit><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>e_BBTeff</name><description>[0.03/1.3] 90% lower error in BBTeff</description><unit>1000K</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>BBrChi2</name><description>[0/10]? Reduced {chi}^2^ of BB fit (5)</description><ucd>stat.fit.param;meta.modelled</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>PLAv</name><description>[0/1.31] Foreground extinction from PL fit (3)</description><unit>mag</unit><ucd>phys.absorption</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>E_PLAv</name><description>[0.01/0.2]? 90% upper error in PLAv</description><unit>mag</unit><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>e_PLAv</name><description>[0.01/0.2]? 90% lower error in PLAv</description><unit>mag</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>PLNorm</name><description>[0.38/76.6] Norm from PL fit</description><unit>1e-28mW.m**-2.Hz**-1</unit><ucd>stat.fit.param</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>E_PLNorm</name><description>[0.1/6] 90% upper error in PLNorm</description><unit>1e-28mW.m**-2.Hz**-1</unit><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>e_PLNorm</name><description>[0.08/5.5] 90% lower error in PLNorm</description><unit>1e-28mW.m**-2.Hz**-1</unit><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>PLInd</name><description>[0.2/9.1] Spectral index from PL fit</description><ucd>spect.index</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>E_PLInd</name><description>[0.2/1.3] 90% upper error in PLInd</description><ucd>stat.error;stat.max</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>e_PLInd</name><description>[0.2/1.3] 90% lower error in PLInd</description><ucd>stat.error</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>PLChi2</name><description>[0/340] Chi-square from PL fit</description><ucd>meta.note</ucd><dataType xsi:type="vs:VOTableType">float</dataType></column><column><name>PLrChi2</name><description>[0.02/111]? Reduced chi-square from PL fit (5)</description><ucd>meta.note</ucd><dataType xsi:type="vs:VOTableType">float</dataType><flag>nullable</flag></column><column><name>BBbest</name><description>Identify BB as the best-fit model</description><ucd>meta.code</ucd><dataType xsi:type="vs:VOTableType" arraysize="3*">char</dataType></column><column><name>PLbest</name><description>Identify PL as the best-fit model</description><ucd>meta.code</ucd><dataType xsi:type="vs:VOTableType" arraysize="3*">char</dataType></column></table></schema></tableset></ri:Resource>