The Most Massive Black Hole in a Compact Galaxy UGC 2698

Massive galaxies represent the extreme of galaxy formation and contain the most massive black holes (BH), as reflected in the scaling relations of BH masses with galaxy velocity dispersions (MÔÇô¤â) and luminosities (MÔÇôL). Our spectroscopic survey of 900 nearby galaxies has already yielded one of the most massive black holes in a remarkably compact galaxy NGC1277. Now we propose to obtain imaging of a nearby galaxy which may host the most massive black hole found to date. This galaxy, UGC2698, lies nearby at a distance of 89 Mpc and has an average size and luminosity, and a extremely high central velocity dispersion of 440 km/s, indicative of black hole mass in excess 10 billion solar masses. With one orbit, we can resolve its small bulge and put accurate constraints on its black hole mass {in combination with our spectroscopy}. If this system also contains a very high black hole mass, it would be in stark conflict with the popular co-evolution picture.