J/ApJ/836/50ivo://CDS.VizieR/J/ApJ/836/50doi:10.26093/cds/vizier.18360050CDSLaycock S.Cappallo R.Williams B.F.Prestwich A.Binder B.,Christodoulou D.M.2020-01-17T05:11:18Z2017-10-13T13:51:50ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frx-ray-sourcesx-ray-binary-starsgalaxiesWe have monitored the Cassiopeia dwarf galaxy (IC 10) in a series of 10 Chandra ACIS-S observations to capture its variable and transient X-ray source population, which is expected to be dominated by High Mass X-ray Binaries (HMXBs). We present a sample of 21 X-ray sources that are variable between observations at the 3{sigma} level, from a catalog of 110 unique point sources. We find four transients (flux variability ratio greater than 10) and a further eight objects with ratios >5. The observations span the years 2003-2010 and reach a limiting luminosity of >10^35^erg/s, providing sensitivity to X-ray binaries in IC 10 as well as flare stars in the foreground Milky Way. The nature of the variable sources is investigated from light curves, X-ray spectra, energy quantiles, and optical counterparts. The purpose of this study is to discover the composition of the X-ray binary population in a young starburst environment. IC 10 provides a sharp contrast in stellar population age (<10My) when compared to the Magellanic Clouds (40-200My) where most of the known HMXBs reside. We find 10 strong HMXB candidates, 2 probable background Active Galactic Nuclei, 4 foreground flare-stars or active binaries, and 5 not yet classifiable sources. Complete classification of the sample requires optical spectroscopy for radial velocity analysis and deeper X-ray observations to obtain higher S/N spectra and search for pulsations. A catalog and supporting data set are provided.2017ApJ...836...50Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/836/50CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-2014)J/A+A/424/125 : Carbon stars in IC10 (Demers+, 2004)J/ApJS/150/19 : ChaMP. I. First X-ray source catalog (Kim+, 2004)J/MNRAS/362/1065 : XMM/Chandra study of IC 10 (Wang+, 2005)J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)J/MNRAS/388/1198 : Be/X-ray binaries in Small Magellanic Cloud (McBride+, 2008)J/PAZh/35/829 : Star clusters in IC 10 (Tikhonov+, 2009)J/ApJ/721/1368 : X-ray emission from the Sombrero galaxy (Li+, 2010)J/ApJS/192/10 : Chandra ACIS survey in 383 nearby galaxies. I. (Liu, 2011)J/ApJS/193/31 : M33 Chandra ACIS survey: final catalog (Tullmann+, 2011)J/AJ/150/94 : Chandra Local Volume Survey. I. (Binder+, 2015)J/ApJS/216/10 : DUSTiNGS. I. The Good Source Catalog (Boyer+, 2015)J/ApJS/218/9 : Deep XMM-Newton survey of M33 (Williams+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/836/50https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/836/50http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/836/50https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/836/50https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/836/50http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/836/50GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/836/50/table2 (Chandra ACIS-S source catalog of IC 10)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/836/50/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/836/50/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/836/50/table2?GETtext/xml+votable180.050000true5.036209543759.2279352420.005555555555555556Cone search capability for table J/ApJ/836/50/table1 (Chandra observations of IC 10)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/836/50/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/836/50/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/836/50/table1?GETtext/xml+votable180.050000true5.1041759.281940.0055555555555555566/3042 3043https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/836/50?format=asciiX-raydefaultJ/ApJ/836/50/table2Chandra ACIS-S source catalog of IC 10LCLCs interactive plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/111] Running sequence numbermeta.idintCXOUChandra coordinate-based identifier (JHHMMSS.S+DDMMSS)meta.id;meta.maincharW05Cross reference (1)meta.id.crosscharSrcIDSoure identifier within the observation (2)meta.id;obs.param;obscharRAJ2000Right Ascension in decimal degrees (J2000) (3)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000) (3)degpos.eq.dec;meta.mainErr95[0.2/6] Positional uncertainty radius at 95% confidence (4)degstat.error;phys.angSizefloatNP[2/10] Number of observations source was in FoV of ACIS S-3 detectormeta.id;instr.fovintNB[0/10] Number of observations source was detected in 0.3-8keV bandmeta.numberint<CRate>[0.0002/0.2]? Average 0.3-8keV band count rate (4)ct/sphot.count;em.X-raydoublenullableRMS[/0.06]? Root-mean-squared 0.3-8keV band count rate (4)ct/sstat.errordoublenullableMin[/0.03]? Minimum observed 0.3-8keV band count ratect/sphot.count;em.X-raydoublenullablee_Min[/0.002]? Error in Minct/sstat.error;stat.mindoublenullableMax[/0.2]? Maximum observed 0.3-8keV band count ratect/sphot.count;em.X-raydoublenullablee_Max[/0.003]? Error in Maxct/sstat.error;stat.maxdoublenullableRange[/0.2]? Range of observed fluxes; Max-Minct/sphot.count;em.X-raydoublenullableRatio[0/118] Ratio of Max/Min count ratesphot.count;arith.ratiodoubleVar[0.06/56]? Variability index {sigma}_var_ (5)src.var.indexfloatnullableNCts[1/22632]? Net counts across all observationsctphot.count;em.X-raydoublenullableEvents[0/28667] Total number of events (6)meta.numberintEMed[732/7951]? Median energy of events (6)eVem.energyfloatnullablee_EMed[47/3069]? Standard deviation in EMedeVstat.errorfloatnullableEvBack[0/236] Number of events in background annulus region (7)meta.numberintEMedB[74/7952]? Median energy of events in background annulus region (7)eVem.energyfloatnullablee_EMedB[26/3367]? Standard deviation in EMedBeVstat.errorfloatnullableQDx[-1.3/2.2]? Spectral Slope Quantile QDx (8)spect.indexdoublenullablee_QDx[-1000/-0.02]? Lower 1{sigma} bound on QDxstat.errordoublenullableE_QDx[-0.6/1.6]? Upper 1{sigma} bound on QDxstat.error;stat.maxdoublenullableQDy[0.007/3]? Spectral Slope Quantile QDy (8)spect.indexdoublenullablee_QDy[-3/-0.007]? Lower 1{sigma} bound on QDystat.errordoublenullableE_QDy[0.01/2.5]? Upper 1{sigma} bound on QDystat.error;stat.maxdoublenullableVarClVariable X-ray source code(s) (9)meta.code;src.varcharJ/ApJ/836/50/table1Chandra observations of IC 10recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD? Modified Julian Date of the observationdtime.epochfloatnullableDateUT date of observationtime.epoch;obsnullableDay2Other days of observationtime.epochcharObsIDChandra ObsIDmeta.noteintf_ObsIDFlag on ObsID (1)meta.codecharExp[8/81] Exposure timekstime.duration;obs.exposurefloatRAJ2000? Hour of right ascension (J2000)pos.eq.ra;meta.mainnullableDEJ2000? Degree of declination (J2000)pos.eq.dec;meta.mainnullableRoll[10/340]? Roll angledeginstr.offsetfloatnullableNsrc[19/63] Number of unique point sources detected (2)meta.numberintJ/ApJ/836/50/variablesLight-curves of variable X-ray sources (fig3-5)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/90] Source identifier (1)meta.idintMJDModified Julian Date of observationdtime.epochdoubleNCR[/0.2] Net count ratect/sphot.count;em.X-raydoublee_NCR[/0.004]? Uncertainty in NCRct/sstat.errordoublenullableBandBand/Limit code (2)instr.bandpasscharClmeta.codechar