J/ApJ/700/1702ivo://CDS.VizieR/J/ApJ/700/1702doi:10.26093/cds/vizier.17001702CDSvan den Berg M.Hong J.Grindlay J.E.2017-06-30T05:47:47Z2011-09-21T15:47:03ZCDS support team

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

cds-question@unistra.frcataclysmic-variable-starsx-ray-sourcessurveyshst-photometryWe have carried out a deep X-ray and optical survey with Chandra and HST of low-extinction regions in the Galactic bulge. Here we present the results of a search for low-luminosity (L_X_<~10^34^erg/s) accreting binaries among the Chandra sources in the region closest to the Galactic center, at an angular offset of 1.4{deg}, that we have named the Limiting Window (LW). Based on their blue optical colors, excess H{alpha} fluxes, and high X-ray-to-optical flux ratios, we identify three likely accreting binaries; these are probably white dwarfs accreting from low-mass companions (cataclysmic variables; CVs) although we cannot exclude that they are quiescent neutron-star or black-hole low-mass X-ray binaries. Distance estimates put these systems farther than >~2kpc. Based on their H{alpha}-excess fluxes and/or high X-ray-to-optical flux ratios, we find 22 candidate accreting binaries; however, the properties of some can also be explained if they are dMe stars or active galaxies.2009ApJ...700.1702Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/700/1702CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-)B/hst : HST Archived Exposures Catalog (STScI, 2007)I/315 : UCAC3 Catalogue (Zacharias+ 2009)II/213 : OGLE Galactic Bulge periodic variables (Udalski+ 1996)J/ApJ/685/463 : ChaMPlane X-ray sources in the Galactic bulge (Koenig+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/700/1702https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/700/1702http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/700/1702https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/700/1702https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/700/1702http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/700/1702GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/700/1702/lw_opt (Candidate accreting binaries in the Limiting Window (LW) selected on optical colors or on X/optical ratio and other sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/700/1702/lw_opt?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/700/1702/lw_opt?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/700/1702/lw_opt?GETtext/xml+votable180.050000true267.837125-29.5551250.005555555555555556Cone search capability for table J/ApJ/700/1702/table1 (Chandra sources in the ACS field of view)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/700/1702/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/700/1702/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/700/1702/table1?GETtext/xml+votable180.050000true267.913333-29.5761110.0055555555555555566/28822https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/700/1702?format=asciiX-raydefaultJ/ApJ/700/1702/lw_optCandidate accreting binaries in the Limiting Window (LW) selected on optical colors or on X/optical ratio and other sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLW[1/43] Source name <[VHG2009] LW NN> in Simbadmeta.id;meta.mainintu_LW[b] Ambiguous identification (1)meta.code.errorcharCXOPSChandra source name (HHMMSS.s+DDMMSS; J2000)meta.idcharCtsNet source counts in the B_x_ band (0.3-8keV)ctphot.count;em.X-rayinte_CtsCts uncertaintyctstat.errorintE50? Median energy E_50_ in the B_x_ bandkeVem.energyfloatnullablee_E50? E50 uncertaintykeVstat.errorfloatnullableGp[1,3] Quantile spectral group (4)meta.idintRAJ2000? Optical hour of right ascension (J2000) (2)pos.eq.ra;meta.mainnullableDEJ2000Optical sign of declination (J2000) (2)pos.eq.dec;meta.mainnullableR625? HST/ACS R-band magnitude (F625W) unless flagged (not for table 4)magphot.mag;em.opt.Rfloatnullablef_R625[a] Flag on R625 (3)meta.codecharB435? HST/ACS B-band magnitude (F435W) (not for table 4)magphot.mag;em.opt.BfloatnullableHa? H{alpha} magnitude (not for table 4)magphot.flux;em.line.HalphafloatnullablelogX/RRatio of the observed (log(f_X_/f_R_)) X-ray and optical fluxes (4)phot.flux;arith.ratiofloate_logX/RlogX/R uncertainty (4)stat.errorfloatf_logX/R[acd] Flag on logX/R (3)meta.codecharlogX/RuRatio of the intrinsic (log(f_X_/f_R_)_u_) X-ray and optical fluxes (4)phot.flux;arith.ratiofloate_logX/RulogX/Ru uncertainty (4)stat.errorfloatf_logX/Ru[acd] Flag on logX/Ru (3)meta.codecharComCommentmeta.notecharJ/ApJ/700/1702/table1Chandra sources in the ACS field of viewrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXOPSSource name (HHMMSS.s+DDMMSS; J2000)meta.id;meta.maincharprimaryf_CXOPS[a] Source partly in chip gap (1)meta.codecharl_SNRh[-] The source was not significantly detected in the hard bandmeta.code.errorcharSNRhHard (2-8keV) band signal-to-noise ratiostat.snrfloatLW[1/43]? LW identifier if in Limiting Windowmeta.id.crossintnullableprimaryT[3,5]? table number (3+4 = accreting binary candidates; 5 = other optical sources)meta.idintnullable_RAPositions from CXOPS name (right ascension part)degpos.eq.ra;meta.main_DEPositions from CXOPS name (declination part)degpos.eq.dec;meta.main