Cosmic evolution of black holes and galaxies to z=0.4

We test the evolution of the correlation between black hole mass and bulge properties, using a carefully selected sample of 20 Seyfert 1 galaxies at z=0.36 ±0.01. We estimate black hole mass from the Hβ line width and the optical luminosity at 5100 Å, based on the empirically calibrated photo-ionization method. Velocity dispersion are measured from stellar absorption lines around Mgb (5175 Å) and Fe (5270 Å) using high S/N Keck spectra, and bulge properties (luminosity and effective radius) are measured from HST images by fitting surface brightness. We find a significant offset from the local relations, in the sense that bulge sizes were smaller for given black hole masses at z=0.36 than locally. The measured offset is Δ M•=0.62 ± 0.10, 0.45 ±0.13, 0.59 ±0.19, respectively for M•-σ, M•-L_bulge, and M•-M_bulge relations. At face value, this result implies a substantial growth of bulges in the last 4 Gyr, assuming that the local M•-bulge property relation is the universal evolutionary end-point. This result is consistent with the growth of black holes predating the final growth of bulges at these mass scales (<σ>=170 km s⁻¹).