eROSITA catalogue of X-ray active dwarf galaxies

We 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.

Cone search capability for table J/MNRAS/527/1962/dwarfs (SRG/eROSITA-SDSS catalogue of dwarf galaxies with nuclear X-ray activity (table A1))

Cone search capability for table J/MNRAS/527/1962/excluded (Catalogue of excluded sources (table A2))

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/527/1962
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/527/1962
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/527/1962
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/527/1962
Provenance
Creator Bykov S.; Gilfanov M.; Sunyaev R.
Publisher CDS
Publication Year 2023
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Physics