Authors: Alister W. Graham, Mark Durré, Giulia A.D. Savorgnan, Anne M. Medling, Dan Batcheldor, Nicholas Scott, Beverly Watson and Alessandro Marconi
Abstract: The identification of galaxies with `overly massive' black holes obviously requires two measurements: a black hole mass and a host spheroid mass. Here we provide our measurements for NGC 1277. Our structural decomposition of this galaxy reveals that it is dominated by a `classical' spheroid with a Sérsic index n = 5.3, a half-light radius Re,major = 2.1 kpc, and a stellar mass of 2.77×1011 MSun (using M*/Lsph=11.65, Martin-Navarro et al.). This mass is an order of magnitude greater than originally reported. Using the latest Mbh-n, Mbh-Msph,*, and Mbh-σ relations, the expected black hole mass is respectively (0.57+1.29-0.40)×109 MSun, (1.58+4.04-1.13)×109 MSun, and (2.27+4.04-1.44)×109 MSun (using σ = 300 km/s) for which the `sphere-of-influence' is 0.31 arcseconds for this larger mass. Our new kinematical maps obtained from laser guide star assisted, adaptive optics on the Keck I Telescope confirm the presence of the inner, nearly edge-on, disk seen in the galaxy image. This disk produces a large velocity shear of some 400 km/s across the inner 0.2 arcseconds (70 parsec) plus elevated values of √ σ2+V2 across the inner (±1.9)×(±0.3) arcsec region of the galaxy. Unfortunately, this disk also results in our new multi-Gaussian expansion (MGE) models and Jeans Anisotropic MGE (JAM) analysis struggling to derive a robust black hole mass. Our best measure, albeit a probable upper limit, is 1.2×109 MSun (M/LV = 12.3). This is an order of magnitude smaller than originally reported and 4 times smaller than recently reported. It gives an Mbh/Msph,* ratio of 0.45% in agreement with the median (0.5%) and range (0.1-5.0%) observed in non-dwarf, early-type galaxies.