The Black Hole in the Most Massive Ultracompact Dwarf Galaxy M59-UCD3 Academic Article uri icon


  • 2018. The American Astronomical Society. All rights reserved. We examine the internal properties of the most massive ultracompact dwarf galaxy (UCD), M59-UCD3, by combining adaptive-optics-assisted near-IR integral field spectroscopy from Gemini/NIFS and Hubble Space Telescope (HST) imaging. We use the multiband HST imaging to create a mass model that suggests and accounts for the presence of multiple stellar populations and structural components. We combine these mass models with kinematics measurements from Gemini/NIFS to find a best-fit stellar mass-to-light ratio (M/L) and black hole (BH) mass using Jeans anisotropic models (JAMs), axisymmetric Schwarzschild models, and triaxial Schwarzschild models. The best-fit parameters in the JAM and axisymmetric Schwarzschild models have BHs between 2.5 and 5.9 million solar masses. The triaxial Schwarzschild models point toward a similar BH mass but show a minimum 2 at a BH mass of 0. Models with a BH in all three techniques provide better fits to the central V rms profiles, and thus we estimate the BH mass to be 4.2+2.1-1.7 106M o (estimated 1 uncertainties). We also present deep radio imaging of M59-UCD3 and two other UCDs in Virgo with dynamical BH mass measurements, and we compare these to X-ray measurements to check for consistency with the fundamental plane of BH accretion. We detect faint radio emission in M59cO but find only upper limits for M60-UCD1 and M59-UCD3 despite X-ray detections in both these sources. The BH mass and nuclear light profile of M59-UCD3 suggest that it is the tidally stripped remnant of a 109-1010 M o galaxy.

published proceedings


altmetric score

  • 3.5

author list (cited authors)

  • Ahn, C. P., Seth, A. C., Cappellari, M., Krajnovic, D., Strader, J., Voggel, K. T., ... Spitler, L.

citation count

  • 54

complete list of authors

  • Ahn, Christopher P||Seth, Anil C||Cappellari, Michele||Krajnovic, Davor||Strader, Jay||Voggel, Karina T||Walsh, Jonelle L||Bahramian, Arash||Baumgardt, Holger||Brodie, Jean||Chilingarian, Igor||Chomiuk, Laura||den Brok, Mark||Frank, Matthias||Hilker, Michael||McDermid, Richard M||Mieske, Steffen||Neumayer, Nadine||Nguyen, Dieu D||Pechetti, Renuka||Romanowsky, Aaron J||Spitler, Lee

publication date

  • January 2018