Massive Star-forming Host Galaxies of Quasars on Sloan Digital Sky Survey Stripe 82

The stellar properties of about 800 galaxies hosting optically luminous, unobscured quasars at z 1010 M ?), which is consistent with previous results for less luminous narrow-line (obscured) active galactic nuclei (AGNs). The quasar hosts are very blue and almost absent on the red sequence, showing stark contrast to the color-magnitude distribution of normal galaxies. The fact that more powerful AGNs reside in galaxies with higher star-formation efficiency may indicate that negative AGN feedback, if it exists, is not concurrent with the most luminous phase of AGNs. We also find positive correlation between the mass of supermassive black holes (SMBHs; M BH) and host stellar mass, but the M BH-M star relation is offset toward large M BH or small M star compared to the local relation. While this could indicate that SMBHs grow earlier than do their host galaxies, such an argument is not conclusive, as the effect may be dominated by observational biases.