A supermassive black hole in an ultra-compact dwarf galaxy. Academic Article uri icon


  • Ultra-compact dwarf galaxies are among the densest stellar systems in the Universe. These systems have masses of up to 210(8) solar masses, but half-light radii of just 3-50parsecs. Dynamical mass estimates show that many such dwarfs are more massive than expected from their luminosity. It remains unclear whether these high dynamical mass estimates arise because of the presence of supermassive black holes or result from a non-standard stellar initial mass function that causes the average stellar mass to be higher than expected. Here we report adaptive optics kinematic data of the ultra-compact dwarf galaxy M60-UCD1 that show a central velocity dispersion peak exceeding 100kilometres per second and modest rotation. Dynamical modelling of these data reveals the presence of a supermassive black hole with a mass of 2.110(7) solar masses. This is 15 per cent of the object's total mass. The high black hole mass and mass fraction suggest that M60-UCD1 is the stripped nucleus of a galaxy. Our analysis also shows that M60-UCD1's stellar mass is consistent with its luminosity, implying a large population of previously unrecognized supermassive black holes in other ultra-compact dwarf galaxies.

published proceedings

  • Nature

altmetric score

  • 547.136

author list (cited authors)

  • Seth, A. C., van den Bosch, R., Mieske, S., Baumgardt, H., den Brok, M., Strader, J., ... Walsh, J. L.

citation count

  • 193

complete list of authors

  • Seth, Anil C||van den Bosch, Remco||Mieske, Steffen||Baumgardt, Holger||den Brok, Mark||Strader, Jay||Neumayer, Nadine||Chilingarian, Igor||Hilker, Michael||McDermid, Richard||Spitler, Lee||Brodie, Jean||Frank, Matthias J||Walsh, Jonelle L

publication date

  • January 2014

published in