J/MNRAS/527/1962 eROSITA catalogue of X-ray active dwarf galaxies (Bykov+, 2024)
SRG/eROSITA catalogue of X-ray active SDSS dwarf galaxies.
Bykov S., Gilfanov M., Sunyaev R.
<Mon. Not. R. Astron. Soc. 527, 1962-1981 (2024)>
=2024MNRAS.527.1962B 2024MNRAS.527.1962B (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; X-ray sources
Keywords: galaxies: active - galaxies: dwarf - X-rays: galaxies -
cosmology: observations - transients: tidal disruption events -
accretion, accretion discs
Abstract:
We present a sample of 99 dwarf galaxies (M*<109.5M☉) 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∼1039erg/s to
~(2-4)x10-4 at LX∼1041erg/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.
Description:
Sample of dwarf galaxies with X-ray emission detected by eROSITA,
consistent with being an AGN.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
dwarfs.dat 1096 99 SRG/eROSITA-SDSS catalogue of dwarf galaxies
with nuclear X-ray activity (table A1)
excluded.dat 455 79 Catalogue of excluded sources (table A2)
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Byte-by-byte Description of file: dwarfs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ID Identification number (ID)
7- 16 F10.6 deg RAdeg Right ascension (J2000) (RA)
18- 28 F11.8 deg DEdeg Declination (J2000) (DEC)
30- 50 F21.19 --- z Redshift (z)
52- 63 F12.1 Msun Mass Stellar mass (mass)
65- 78 E14.6 Msun/yr SFR Star formation rate (sfr)
80- 101 E22.16 10-7W LX0.3-8 X-ray luminosity in 0.3-8keV band
(Lx03_80)
103- 125 F23.16 --- LX/LXRB Ratio of X-ray luminosity to the
luminosity of the X-ray binaries/gas
in the galaxy, all 0.5-8keV
(LxLXRBrat)
127- 152 A26 --- SMAIN-ID SIMBAD name of the closest galaxy to
the dwarf position
(simbaddwarfMAIN_ID)
154- 189 A36 --- SOTYPE-V SIMBAD object type of that galaxy
(simbaddwarfOTYPE_V)
191- 209 F19.16 arcsec SepDe Angular separation between the dwarf
and the eROSITA source position
(sep_ero)
211- 231 A21 --- eROSITA eROSITA source name (srcnamefinero)
233- 252 F20.15 --- DL-0-ero eROSITA source detection likelihood
in the 0.3-2.3keV band
(DETLIKE0_ero)
254- 265 F12.9 --- SepdS ? Angular separation between the
dwarf and the closest SIMBAD galaxy
(simbaddwarfsep)
267- 286 F20.16 deg RAedeg eROSITA source right ascension
(J2000) (RAfinero)
288- 307 F20.17 deg DEedeg eROSITA source declination (J2000)
(DECfinero)
309- 327 F19.15 --- MLCTS-0-ero Best-fitting X-ray source counts in
the 0.3-2.3 keV band (MLCTS0_ero)
329- 347 F19.16 --- e_MLCTS-0-ero ? Error on X-ray source counts
(MLCTSERR0ero)
349- 367 F19.16 arcsec pos-r98c-ero eROSITA source position error,
corrected (posr98cero)
369- 387 I19 --- specobjid Id of SDSS spectrum (specobjid)
389- 393 I5 d SDSS-MJD Date of SDSS spectrum (mpajhuMJD)
395- 398 I4 --- SDSS-Plate SDSS plate id (mpajhuPLATEID)
400- 402 I3 --- SDSS-Fiber SDSS fiber id (mpajhuFIBERID)
404- 409 A6 --- SDSSspType SDSS spectral type
(mpajhuSPECTROTYPE)
411- 421 A11 --- SDSSsubClass SDSS spectral subclass
(mpajhuSUBCLASS)
423- 434 F12.10 --- SDSSz SDSS redshift (mpajhuz)
436- 449 E14.8 --- e_SDSSz SDSS redshift error (mpajhuz_err)
451- 452 I2 --- SDSSz-warn SDSS redshift warning
(mpajhuz_warn)
454- 467 A14 --- SDSSBPTClass SDSS BPT classification
(mpajhubpt_class)
469- 481 F13.2 Msun e_Mass Stellar mass lower error
(68% confidence) (mass_lo)
483- 495 F13.2 Msun E_Mass Stellar mass upper error (mass_hi)
497- 511 E15.7 Msun/yr e_SFR SFR lower error (68% confidence)
(sfr_lo)
513- 527 E15.7 Msun/yr E_SFR SFR upper error (sfr_hi)
529 I1 --- reliable [1] if the parameters are reliable
(1) or not (0) (reliable)
531- 544 F14.8 10-20W/m2 SDSSFOIII Flux of [OIII] 5007
(mpajhuOIII5007FLUX)
546- 556 F11.7 10-20W/m2 e_SDSSFOIII Flux error of [OIII] 5007
(mpajhuOIII5007FLUX_ERR)
558- 569 F12.8 --- SDSSFOIIISNR SNR of [OIII] 5007
(mpajhuOIII5007FLUX_SNR)
571- 582 F12.7 10-20W/m2 SDSSFNII Flux of [NII] 6584
(mpajhuNII6584FLUX)
584- 593 F10.7 10-20W/m2 e_SDSSFNII Flux error of [NII] 6584
(mpajhuNII6584FLUX_ERR)
595- 606 F12.8 --- SDSSFNIISNR SNR of [NII] 6584
(mpajhuNII6584FLUX_SNR)
608- 623 F16.7 10-20W/m2 SDSSFHa Flux of Halpha (mpajhuHALPHAFLUX)
625- 640 F16.8 10-20W/m2 e_SDSSFHa Flux error of Halpha
(mpajhuHALPHAFLUX_ERR)
642- 652 F11.7 --- SDSSFHaSNR SNR of Halpha
(mpajhuHALPHAFLUX_SNR)
654- 667 F14.8 10-20W/m2 SDSSFHb Flux of Hbeta (mpajhuHBETAFLUX)
669- 679 F11.7 10-20W/m2 e_SDSSFHb Flux error of Hbeta
(mpajhuHBETAFLUX_ERR)
681- 692 F12.8 --- SDSSFHbSNR SNR of Hbeta
(mpajhuHBETAFLUX_SNR)
694- 706 F13.8 --- SDSSOIII-Hb BPT diagram position
(mpajhuBPTOIIIH_BETA)
708- 720 F13.10 --- SDSSNII-Ha BPT diagram position
(mpajhuBPTNIIH_ALPHA)
722- 733 F12.10 --- NLMXB Expected number of LMXBs (N_LMXB)
735- 748 F14.10 --- NHMXB Expected number of HMXBs (N_HMXB)
750- 771 E22.16 --- LXRB total luminosity of XRBs (L_XRB)
773- 777 A5 [10-7W] logLHMXB log of HMXB luminosity (logLHMXB)
779- 783 A5 [10-7W] logLgas log of hot ISM gas luminosity
(logLgas)
785- 789 F5.2 [10-7W] logLLMXB log of LMXB luminosity (logLLMXB)
791- 812 E22.16 10-7W LX0.3-2 X-ray luminosity in 0.3-2keV band
(Lx03_20)
814- 835 E22.16 10-7W e_LX0.3-2 X-ray luminosity in 0.3-2keV band,
lower error (90% confidence)
(Lx0320lo)
837- 858 E22.16 10-7W E_LX0.3-2 X-ray luminosity in 0.3-2keV band,
upper error (Lx0320hi)
860- 881 E22.16 10-7W LX0.5-2 X-ray luminosity in 0.5-2keV band
(Lx05_20)
883- 904 E22.16 10-7W e_LX0.5-2 X-ray luminosity in 0.5-2keV band,
lower error (90% confidence)
(Lx0520lo)
906- 927 E22.16 10-7W E_LX0.5-2 X-ray luminosity in 0.5-2keV band,
upper error (Lx0520hi)
929- 950 E22.16 10-7W LX2-8 X-ray luminosity in 2-8keV band
(Lx20_80)
952- 973 E22.16 10-7W e_LX2-8 X-ray luminosity in 2-8keV band,
lower error (90% confidence)
(Lx2080lo)
975- 996 E22.16 10-7W E_LX2-8 X-ray luminosity in 2-8keV band,
upper error (Lx2080hi)
998-1008 A11 --- spemodel Model used for X-ray spectral fits
(spemodel)
1010-1031 E22.16 10-7W LX0.5-8 X-ray luminosity in 0.5-8keV band
(Lx05_80)
1033-1054 E22.16 10-7W e_LX0.5-8 X-ray luminosity in 0.5-8keV band,
lower error (Lx0580err_lo)
1056-1077 E22.16 10-7W E_LX0.5-8 X-ray luminosity in 0.3-8keV band,
upper error (Lx0380err_hi)
1079-1096 F18.16 --- VarR ? Variability index R (variability_R)
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Byte-by-byte Description of file: excluded.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ID Identification number (ID)
7- 16 F10.6 deg RAdeg Right ascension (J2000) (RA)
18- 29 F12.8 deg DEdeg Declination (J2000) (DEC)
31- 51 F21.19 --- z Redshift (z)
53- 64 F12.1 Msun Mass Stellar mass (mass)
66- 78 F13.11 Msun/yr SFR Star formation rate (sfr)
80-107 A28 --- SMAIN-ID SIMBAD name of the closest galaxy to
the dwarf position
(simbaddwarfMAIN_ID)
109-144 A36 --- SOTYPE-V SIMBAD object type of that galaxy
(simbaddwarfOTYPE_V)
146-164 F19.17 arcsec SepDe Angular separation between the dwarf
and the eROSITA source position
(sep_ero)
166-186 A21 --- eROSITA eROSITA source name (srcnamefinero)
188-206 F19.15 deg RAedeg eROSITA source right ascension
(J2000) (RAfinero)
208-228 F21.17 deg DEedeg eROSITA source declination (J2000)
(DECfinero)
230-249 F20.15 --- DL-0-ero eROSITA source detection likelihood
in the 0.3-2.3keV band
(DETLIKE0_ero)
251-272 E22.17 10-20W/m2 F0.5-20 Flux in 0.5-20keV band (flux05-20ero)
274-292 F19.16 arcsec pos-r98c-ero eROSITA source position error,
corrected (posr98cero)
294-312 I19 --- specobjid Id of SDSS spectrum (specobjid)
314-318 I5 d SDSS-MJD Date of SDSS spectrum (mpajhuMJD)
320-323 I4 --- SDSS-Plate SDSS plate id (mpajhuPLATEID)
325-327 I3 --- SDSS-Fiber SDSS fiber id (mpajhuFIBERID)
329-334 A6 --- SDSSspType SDSS spectral type
(mpajhuSPECTROTYPE)
336-346 A11 --- SDSSsubClass SDSS spectral subclass
(mpajhuSUBCLASS)
348-360 F13.11 --- SDSSz SDSS redshift (mpajhuz)
362-375 E14.11 --- e_SDSSz SDSS redshift error (mpajhuz_err)
377-378 I2 --- SDSSz-warn SDSS redshift warning
(mpajhuz_warn)
380-393 F14.3 Msun e_Mass Stellar mass lower error
(68% confidence) (mass_lo)
395-408 F14.2 Msun E_Mass Stellar mass upper error (mass_hi)
410-422 E13.11 Msun/yr e_SFR SFR lower error (68% confidence)
(sfr_lo)
424-436 F13.11 Msun/yr E_SFR SFR upper error (sfr_hi)
438 I1 --- reliable [1] if the parameters are reliable
(1) or not (0) (reliable)
440-455 A16 --- Reasons Excluded reasons (EXCLUDED_REASON)
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Acknowledgements:
Sergei Bykov, sergei.d.bykov(at)gmail.com
(End) Patricia Vannier [CDS] 08-Dec-2023