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We study a large sample of dwarf galaxies using archival Chandra X-rayobservations, with the aim of detecting accreting intermediate-mass black holes(IMBHs). IMBHs are expected to inhabit dwarf galaxies and to produce specificsignatures in terms of luminosity and X-ray spectra. We report the discovery ofan X-ray source associated with an Abell 85 dwarf galaxy that fits the IMBHdescription. The stellar mass of the host galaxy is estimated to be 2 $\times$10$^8$ $M_\odot$, which makes it one of the least massive galaxies topotentially host an accreting black hole. The source is detected in the softband, under 1 keV, while undetected at higher energies. The X-ray luminosity is$\approx$ 10$^{41}$ erg s$^{-1}$, making it almost three orders of magnitudemore luminous than the most luminous stellar-mass supersoft emitters. From thegalaxy stellar mass vs. black hole mass relation, we estimate the mass to bewithin the intermediate regime. Another method that resulted in an intermediatemass relies on the fact that supersoft emission is expected to be associatedwith high accretion rates, approaching the Eddington limit. We suggest that theobserved offset of the X-ray source from the galactic center ($\approx$ 1.8kpc) is due to galaxy interactions, and we present evidence from the literaturethat supports the relation between black hole activity and galaxy interactions.

An Ultraluminous Supersoft Source in a Dwarf Galaxy of Abell 85: An Intermediate-Mass Black Hole Candidate