GeminiFocus 2014 Year in Review | Page 30

Testing Black Hole Mass Measurements in an Active Galaxy Figure 7. Radial surface brightness profiles of NGC 4151. The Gemini/NIFS data (red) measure stellar features only (which is most relevant to the determination of black hole mass), so they do not show the increase of central surface brightness due to the AGN, which is evident in the Hubble Space Telescope (green) and Ohio State University Bright Spiral Galaxy Survey (blue) images. Supermassive black holes characterize galaxy nuclei, and their masses scale with stellar properties in their hosts. This shows that black