J/MNRAS/527/1962ivo://CDS.VizieR/J/MNRAS/527/1962doi:10.26093/cds/vizier.75271962CDSBykov S.Gilfanov M.Sunyaev R.2026-08-28T11:24:55Z2023-12-11T17:47:06ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleix-ray-sourcesWe present a sample of 99 dwarf galaxies (M*<10^9.5^M_{sun}_) with X-ray activity in their central regions. The sample was obtained from a match of the SRG/eROSITA X-ray catalogue in the eastern galactic hemisphere with the MPA-JHU SDSS catalogue. The obtained matches were cleaned rigorously with the help of external optical catalogues to increase the purity of the sample. This work is the largest study of this kind - X-ray activity in ~85 per cent of matched dwarfs was not reported before. The majority of X-ray active dwarfs are identified as star-forming galaxies. However, the X-ray luminosity of 82 objects cannot be explained by the collective emission of X-ray binaries, rendering them strong candidates for dwarf galaxies with an active accreting black hole in their centre. We find that the fraction of AGN among dwarf galaxies drops from ~2x10^-2^ at LX~10^39^erg/s to ~(2-4)x10^-4^ at LX~10^41^erg/s and increases with the stellar mass of the host galaxy. We serendipitously discovered sources with unexpected properties. We report on a tidal disruption event (TDE) candidate in a dwarf galaxy, a massive black hole in a dwarf galaxy with a soft thermal spectrum, a luminous dwarf galaxy with an obscured X-ray spectrum and a few other peculiar sources. We found three Ultra-luminous X-ray (ULX) source candidates and a sample of X-ray bright galaxy pairs, in four of which both members shine in X-rays.2024MNRAS.527.1962Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/527/1962CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/527/1962https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/527/1962http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/527/1962https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/527/1962https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/527/1962http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/527/1962GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/527/1962/dwarfs (SRG/eROSITA-SDSS catalogue of dwarf galaxies with nuclear X-ray activity (table A1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/527/1962/dwarfs?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/527/1962/dwarfs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/527/1962/dwarfs?GETtext/xml+votable180.050000true253.8891163.2421260.005555555555555556Cone search capability for table J/MNRAS/527/1962/excluded (Catalogue of excluded sources (table A2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/527/1962/excluded?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/527/1962/excluded?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/527/1962/excluded?GETtext/xml+votable180.050000true251.4200164.2112350.0055555555555555566/555 1678 5468 5556 5590 5617 5797 5799 5844 5894 5915 5918 5962 5992 6042 6075 6085 6100 6104 6110 6137 6525 6609 7281 7384 7458 7584 8262 8270 8316 8445 8480 8492 8506 8526 8549 8764 8922 8948 8983 8990 9041 9075 9098 9124 9132 9135 9231 9256 9455 9463 9465 9471 9624 9632 9646 9730 9764 9791 9829 9853 9931 9943 9990-9991 10074 10123 10179 10183 10185 10189 10200 10202 10215 10217 10221 10224 10344 10358 10363 10397 10422 10425 10427 10433 10437 10452 10455 10461 10471 10520 10575 10592 10595 10635 10700 10714 10725 10755 10769 10773 10830 10837 10892 10900 10911 10924 10990 11004 11051 11126 11132 11135 11149-11150 11180 11183 11197 11239-11240 11257 11283 11290 11308 11319 11342 11352 11355 11357 11382 11395 11424 11434 11467 11474 11588 11593 11595 11616 11791 11832 11929 11938 17214 17310 17493 17509 17517 17742 17747 17750 17756 17768 17813 17834 17915 18073 18387 18581 18800 19023 19087 19983 23211 28535 28643 30038 31430 31459 32444https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/527/1962?format=asciiX-raydefaultJ/MNRAS/527/1962/dwarfsSRG/eROSITA-SDSS catalogue of dwarf galaxies with nuclear X-ray activity (table A1)recnoRecord number assigned by the VizieR team. 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Angular separation between the dwarf and the closest SIMBAD galaxy (simbad_dwarf_sep)pos.angDistancedoublenullableRAedegeROSITA source right ascension (J2000) (RA_fin_ero)degpos.eq.raDEedegeROSITA source declination (J2000) (DEC_fin_ero)degpos.eq.decMLCTS-0-eroBest-fitting X-ray source counts in the 0.3-2.3 keV band (ML_CTS_0_ero)phot.count;em.X-ray.softdoublee_MLCTS-0-ero? Error on X-ray source counts (ML_CTS_ERR_0_ero)stat.errordoublenullablepos-r98c-eroeROSITA source position error, corrected (pos_r98c_ero)arcsecstat.error;posdoublespecobjidId of SDSS spectrum (specobjid)meta.idSDSS-MJDDate of SDSS spectrum (mpa_jhu_MJD)dtime.epochintSDSS-PlateSDSS plate id (mpa_jhu_PLATEID)meta.id;instr.plateintSDSS-FiberSDSS fiber id (mpa_jhu_FIBERID)meta.idintSDSSspTypeSDSS spectral type (mpa_jhu_SPECTROTYPE)src.spTypecharSDSSsubClassSDSS spectral subclass (mpa_jhu_SUBCLASS)src.spTypecharSDSSzSDSS redshift (mpa_jhu_z)src.redshift;pos.heliocentricdoublee_SDSSzSDSS redshift error (mpa_jhu_z_err)stat.errordoubleSDSSz-warnSDSS redshift warning (mpa_jhu_z_warn)meta.codeintSDSSBPTClassSDSS BPT classification (mpa_jhu_bpt_class)src.classchare_MassStellar mass lower error (68% confidence) (mass_lo)solMassstat.error;phys.massdoubleE_MassStellar mass upper error (mass_hi)solMassstat.error;stat.maxdoublee_SFRSFR lower error (68% confidence) (sfr_lo)solMass/yrstat.error;phys.SFRdoubleE_SFRSFR upper error (sfr_hi)solMass/yrstat.error;stat.maxdoublereliable[1] if the parameters are reliable (1) or not (0) (reliable)meta.codeintSDSSFOIIIFlux of [OIII] 5007 (mpa_jhu_OIII_5007_FLUX)1e-20W.m**-2phot.fluxdoubleSDSSFOIIISNRSNR of [OIII] 5007 (mpa_jhu_OIII_5007_FLUX_SNR)stat.snrdoubleSDSSFNIIFlux of [NII] 6584 (mpa_jhu_NII_6584_FLUX)1e-20W.m**-2phot.fluxdoublee_SDSSFNIIFlux error of [NII] 6584 (mpa_jhu_NII_6584_FLUX_ERR)1e-20W.m**-2stat.errordoubleSDSSFNIISNRSNR of [NII] 6584 (mpa_jhu_NII_6584_FLUX_SNR)stat.snrdoubleSDSSFHaFlux of Halpha (mpa_jhu_H_ALPHA_FLUX)1e-20W.m**-2phot.flux;em.line.Halphadoublee_SDSSFHaFlux error of Halpha (mpa_jhu_H_ALPHA_FLUX_ERR)1e-20W.m**-2stat.errordoubleSDSSFHbFlux of Hbeta (mpa_jhu_H_BETA_FLUX)1e-20W.m**-2phot.flux;em.line.Hbetadoublee_SDSSFHbFlux error of Hbeta (mpa_jhu_H_BETA_FLUX_ERR)1e-20W.m**-2stat.errordoubleSDSSFHbSNRSNR of Hbeta (mpa_jhu_H_BETA_FLUX_SNR)stat.snrdoubleSDSSOIII-HbBPT diagram position (mpa_jhu_BPT_OIII_H_BETA)stat.fit.paramdoubleSDSSNII-HaBPT diagram position (mpa_jhu_BPT_NII_H_ALPHA)stat.fit.paramdoubleNLMXBExpected number of LMXBs (N_LMXB)meta.numberdoubleNHMXBExpected number of HMXBs (N_HMXB)meta.numberdoubleLXRBtotal luminosity of XRBs (L_XRB)phys.luminosity;em.X-raydoublelogLgaslog of hot ISM gas luminosity (log_L_gas)log(1e-07W)phys.luminositycharlogLLMXBlog of LMXB luminosity (log_L_LMXB)log(1e-07W)phys.luminosity;em.X-rayfloatLX0.3-2X-ray luminosity in 0.3-2keV band (L_x_03_20)1e-07Wphys.luminosity;em.X-ray.softdoublee_LX0.3-2X-ray luminosity in 0.3-2keV band, lower error (90% confidence) (L_x_03_20_lo)1e-07Wstat.errordoubleE_LX0.3-2X-ray luminosity in 0.3-2keV band, upper error (L_x_03_20_hi)1e-07Wstat.error;stat.maxdoubleLX0.5-2X-ray luminosity in 0.5-2keV band (L_x_05_20)1e-07Wphys.luminosity;em.X-ray.softdoublee_LX0.5-2X-ray luminosity in 0.5-2keV band, lower error (90% confidence) (L_x_05_20_lo)1e-07Wstat.errordoubleE_LX0.5-2X-ray luminosity in 0.5-2keV band, upper error (L_x_05_20_hi)1e-07Wstat.error;stat.maxdoubleLX2-8X-ray luminosity in 2-8keV band (L_x_20_80)1e-07Wphys.luminosity;em.X-ray.mediumdoublee_LX2-8X-ray luminosity in 2-8keV band, lower error (90% confidence) (L_x_20_80_lo)1e-07Wstat.errordoubleE_LX2-8X-ray luminosity in 2-8keV band, upper error (L_x_20_80_hi)1e-07Wstat.error;stat.maxdoublespemodelModel used for X-ray spectral fits (spemodel)meta.id;stat.fitcharE_LX0.5-8X-ray luminosity in 0.3-8keV band, upper error (L_x_03_80_err_hi)1e-07Wstat.error;stat.maxdoubleVarR? 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