Observational studies of co-evolution of galaxies and super-massive black holes

1）利用第二类活动星系核（AGN），在红移（z）~0.3（即，约3 Gyr前）和~1.0（8 Gyr前）。所得到的关系在z~0.3处没有明显的演化，而在z~1.0处与现今宇宙相比有轻微的演化。结果表明，在宇宙学时间尺度上，黑洞的生长早于球状体的生长。2）在目标红移~2（10 Gyr前）处寻找最暗的类星体，发现了几个这样的候选者，并研究了它们的详细性质。由于这些类星体可能处于快速成长阶段，它们也可能处于强烈的恒星爆发阶段，并且可能富含分子气体。为了看到它，对其中一个进行了CO观察。事实证明，该物体并不富含气体。3）在本机宇宙中窄线塞弗特1星系中的黑洞应该增长非常迅速，并且处于活动星系核的一个非常年轻的阶段。为了研究黑洞的气体补给机制，对宿主星系的形态进行了研究。棒星系的比例被证明是很高的，这表明棒结构是负责气体燃料。如果黑洞迅速增长，中心区域的星星形成也可能正在活跃地形成恒星。我们对窄线Seyfert 1星系进行了CO观测，但没有发现明显的协同演化证据，结果表明黑洞在宇宙学演化中生长较早，在相同的时间尺度上并不同时发生协同演化。

1)By using type-2 Active Galactic Nuclei (AGNs), relations between black hole mass and luminosity (stellar mass) of the spheroid component of their host galaxies was examined at a redshift (z) of ~0.3 (i.e., about 3 Gyr ago) and ~1.0 (8Gyr ago). The obtained relations do not show a significant evolution at z~0.3 but shows a slight evolution at z~1.0 as compared with that at the present day universe. The results suggest that the black holes grew earlier than the spheroid components with a cosmological time scale.2)A search for the most obscured population of quasars was made at a target redshift of ~2 (10Gyr ago), and a few such candidates were found. Detailed properties of them were studied. Since these quasars may be in the rapid growing phase, they may also be in an intense star-burst phase and may be very molecular gas rich. In order to see it, a CO observation of one of them was made. It was turned out that the object is not very gas rich.3)Black holes in narrow-line Seyfert 1 galaxies in the local universe are supposed to be growing very rapidly and are in a very young phase of AGN. In order to investigate the gas fueling mechanism to black holes, morphology of the host galaxies was studied. The fraction of barred galaxies is turned out to be high, suggesting the bar structure is responsible for the gas fueling. If the black holes grow rapidly, the star formation in the central region may also be actively forming stars. CO observations of the narrow-line Seyfert 1 galaxies were made, but no clear evidence for co-evolution was seen.From these results, it is turned out that black holes grow earlier in terms of cosmological evolution and the simultaneous co-evolution does not occur with the same time-scale.