Hunting for intermediate mass black holes in a sample of close dwarf spheroidal galaxies

Abstract

We analyse archival XMM-Newton and Chandra observations of some dwarf MW satellites and characterized the X-ray source population by cross-correlating with available databases. We also investigate if intermediate-mass black holes are hosted in the center of these galaxies. In the most interesting case of UMI dwarf, we put an upper limit to the central compact object luminosity of ≃ 4 × 10<SUP>33</SUP> erg s<SUP>-1</SUP>. As the target correlates in position also with a radio source, we estimated a black hole mass of ≃ 32.0<SUB>-2.76</SUB><SUP>+2.54</SUP> × 10<SUP>6</SUP> M<SUB>☉</SUB>.