Located in the Perseus cluster , NGC 1271 is an early-type galaxy with a small effective radius of 2.2 kpc and a large bulge stellar velocity dispersion of 276 km s ^ { -1 } for its K -band luminosity of 8.9 \times 10 ^ { 10 } L _ { \odot } .
We present a mass measurement for the black hole in this compact , high-dispersion galaxy using observations from the integral field spectrograph NIFS on the Gemini North telescope assisted by laser guide star adaptive optics , large-scale integral field unit observations with PPAK at the Calar Alto Observatory , and Hubble Space Telescope WFC3 imaging observations .
We are able to map out the stellar kinematics both on small spatial scales , within the black hole sphere of influence , and on large scales that extend out to four times the galaxy ’ s effective radius .
We find that the galaxy is rapidly rotating and exhibits a sharp rise in the velocity dispersion .
Through the use of orbit-based stellar dynamical models , we determine that the black hole has a mass of ( 3.0 ^ { +1.0 } _ { -1.1 } ) \times 10 ^ { 9 } M _ { \odot } and the H -band stellar mass-to-light ratio is 1.40 ^ { +0.13 } _ { -0.11 } \Upsilon _ { \odot } ( 1 \sigma uncertainties ) .
NGC 1271 occupies the sparsely-populated upper end of the black hole mass distribution , but is very different from the Brightest Cluster Galaxies ( BCGs ) and giant elliptical galaxies that are expected to host the most massive black holes .
Interestingly , the black hole mass is an order of magnitude larger than expectations based on the galaxy ’ s bulge luminosity , but is consistent with the mass predicted using the galaxy ’ s bulge stellar velocity dispersion .
More compact , high-dispersion galaxies need to be studied using high spatial resolution observations to securely determine black hole masses , as there could be systematic differences in the black hole scaling relations between these types of galaxies and the BCGs/giant ellipticals , thereby implying different pathways for black hole and galaxy growth .