Stellar Dynamical Method: HST vs Ground (NGC 3115: Kormendy et al. 1996)Stellar Dynamical Method (NGC 3115: Kormendy et al. 1996)Stellar Dynamical Method (M32: van der Marel et al. 1997)Stellar Dynamical Method (M32: van der Marel et al. 1997)(NGC 3379: Gebhardt et al. 2000)(NGC 3379: Gebhardt et al. 2000)(NGC 3379: Gebhardt et al. 2000)(NGC 3379: Gebhardt et al. 2000)Gas Dynamical Method NGC 4258: H2O masers H2O 1.35 cm (22.2 GHz) (Miyoshi et al. 1995)(Miyoshi et al. 1995)NGC 4258: H2O masers (Miyoshi et al. 1995)NGC 4258: H2O masersNGC 4258: H2O masersNGC 4258: H2O masersNGC 4258: H2O masersVelocity → ← Position → GM(r)/r = Vc2(Maoz 1998)log (MBH / Msun)= (8.12 ± 0.08) + (4.24 ± 0.41) log (σe/200 km s-1) (Gultekin et al. 2009)log (MBH / Msun) = (8.95 ± 0.11) + (1.11 ± 0.18) log (LV/1011 Lsun,V) (Gultekin et al. 2009) LV = extinction-corrected V-band bulge/spheroid luminositySMBH – Host Connection  Comments: • This is a relation between sub-pc SMBH and kpc-scale spheroid component  SMBH somehow “knows” about the kpc-scale galaxy and vice-versa! • Doesn’t involve disk component • Doesn’t involve dark matter component, only baryonic matter • SMBHs of active galaxies seem to follow the same relation (modulo a geometry factor based on reverberation mapping; see next chapter!) • Possible origin: mergers + QSO feedback?!?SMBH – Host Connection  Open Issues: • Upturn at high σ (but not L) among bright cluster galaxies (BCGs)? • Scatter at low σ / L among < L* galaxies? Disk contamination? • Where do galaxies with secular / pseudo-bulges fit in? • Where do globular clusters fit in? Are they stripped dwarfs? • Where do intermediate-mass black holes fit