J/A+A/704/A107ivo://CDS.VizieR/J/A+A/704/A107CDSBao T.Ponti G.Haberl F.Mondal S.Morris M.R.Mori K.Mandel S.,Xu X.-J.2026-03-02T06:25:50Z2025-12-08T08:25:40ZCDS support team

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

cds-question@unistra.frgalaxy-planesmilky-way-galaxyx-ray-sourcesx-ray-binary-starsAcross the Galactic disk lies a diverse population of X-ray sources, with the fainter end remaining poorly understood due to past survey sensitivity limits. We aim to classify and characterize faint X-ray sources detected in the eROSITA All-Sky Survey (eRASS1) toward the inner Galactic disk (350<l<360, -1<b<1) using deeper XMM-Newton observations (~20 ks). We analyzed 189 eRASS1 sources, combining X-ray spectral fitting (0.2-10keV) with Gaia astrometric and photometric data for robust classification. Our results show that the eRASS1 catalog toward the Galactic disk is overwhelmingly dominated by coronal sources (~74%), primarily active stars and binaries, with ~8% being wind-powered massive stars and ~18% being accreting compact objects. We propose an empirical hardness-ratio cut (HR>-0.2) to efficiently isolate these non-coronal sources. By stacking the classified population and comparing with the Galactic Ridge X-ray Emission (GRXE) surface brightness, we estimate that ~6% of the GRXE flux in the 0.5-2.0keV band is resolved into point sources above the eRASS1 flux limit (~5x10^-14^erg/cm^2^/s). This resolved soft-band emission is dominated by active stars, while hard-band flux originates primarily from X-ray binaries. We conclude that the eRASS1 catalog retains a non-negligible population of compact objects that can be effectively distinguished using X-ray color selection.2025A&A...704A.107Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/704/A107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)IX/69 : XMM-Newton Serendipitous Source Cat. 4XMM-DR13 (Webb+, 2023)J/A+A/682/A34 : SRG/eROSITA all-sky survey catalogs (eRASS1) (Merloni+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/704/A107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/704/A107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/704/A107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/704/A107https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/704/A107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/704/A107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/704/A107/tablea1 (X-ray properties and classification for 189 eRASS1 sources toward the Galactic disk)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/704/A107/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/704/A107/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/704/A107/tablea1?GETtext/xml+votable180.050000true264.97436-28.496090.0055555555555555565/7202 7204 7206 10614-10615 6/28802-28803 28805-28807 28812-28814 28822 28828 28830 28833 28848-28849 42439 42445 42450-42451 42454-42455https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/704/A107?format=asciiX-raydefaultJ/A+A/704/A107/tablea1X-ray properties and classification for 189 eRASS1 sources toward the Galactic diskrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identifiermeta.id;meta.maincharn_ID[*] Note (1)meta.notecharRAJ2000XMM Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000XMM Declination (J2000)degpos.eq.dec;meta.mainsepXEAngular separation between XMM and eROSITA positionarcsecpos.angDistancefloatsepXGaia? Angular separation between XMM and Gaia positionsarcsecpos.angDistancefloatnullablePfalse? The false-matched rate of the Gaia counterpartstat.fit.goodnessfloatnullableD? Photometric distance from Gaia DR3kpcpos.distancefloatnullablen_D[+] Note (2)meta.notecharType? Source classification from this worksrc.classcharSimbad? Source type in the SIMBADsrc.classcharkTmean? The mean plasma temperaturekeVphys.temperature;stat.meanfloatnullableGamma[G] Note (3)meta.codechare_kTmean? Negative error on kTmeankeVstat.errorfloatnullableE_kTmean? Positive error on kTmeankeVstat.error;stat.maxfloatnullableredchi2? Reduced chi^2 of spectra fittingstat.fit.chi2;stat.fitfloatnullablelogLX? The unabsorbed 0.2-10keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatnullablee_logLX? Negative error on logLXlog(1e-07W)stat.errorfloatnullableE_logLX? Positive error on logLXlog(1e-07W)stat.error;stat.maxfloatnullable