The MASSIVE Survey. XVII. A Triaxial Orbit-based Determination of the Black Hole Mass and Intrinsic Shape of Elliptical Galaxy NGC 2693

Abstract We present a stellar dynamical mass measurement of a newly detected supermassive black hole (SMBH) at the center of the fast-rotating, massive elliptical galaxy NGC 2693 as part of the MASSIVE survey. We combine high signal-to-noise ratio integral field spectroscopy (IFS) from the Gemini Multi-Object Spectrograph with wide-field data from the Mitchell Spectrograph at McDonald Observatory to extract and model stellar kinematics of NGC 2693 from the central 150 pc out to 2.5 effective radii. Observations from Hubble Space Telescope WFC3 are used to determine the stellar light distribution. We perform fully triaxial Schwarzschild orbit modeling using the latest TriOS code and a Bayesian search in 6D galaxy model parameter space to determine NGC 2693's SMBH mass (M BH), stellar mass-to-light ratio, dark matter content, and intrinsic shape. We find ight) imes {10}^{9} {M}_{odot }$?> M BH = 1.7 0.4 10 9 M and a triaxial intrinsic shape with axis ratios p = b/a = 0.902 0.009 and q = c / a = 0.721 0.010 + 0.011 , triaxiality parameter T = 0.39 0.04. In comparison, the best-fit orbit model in the axisymmetric limit and (cylindrical) Jeans anisotropic model of NGC 2693 prefer ight) imes {10}^{9} {M}_{odot }$?> M BH = 2.4 0.6 10 9

Pilawa, J. D., Liepold, C. M., Andrade, S., Walsh, J. L., Ma, C., Quenneville, M. E., Greene, J. E., & Blakeslee, J. P.

Pilawa, Jacob D||Liepold, Christopher M||Andrade, Silvana C Delgado||Walsh, Jonelle L||Ma, Chung-Pei||Quenneville, Matthew E||Greene, Jenny E||Blakeslee, John P

The MASSIVE Survey. XVII. A Triaxial Orbit-based Determination of the Black Hole Mass and Intrinsic Shape of Elliptical Galaxy NGC 2693 Academic Article