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

1)利用2型活动星系核(AGN)，在红移(Z)约0.3(即约3Gyr前)和~1.0(约8Gyr以前)处，研究了黑洞质量与其所在星系球体分量光度(恒星质量)之间的关系。所得到的关系在z~0.3处没有明显的演化，但在z~1.0处与现在的宇宙相比有轻微的演化。2)在目标红移为~2(10Gyr前)的情况下，对最模糊的类星体群进行了搜索，发现了一些这样的候选者。研究了它们的详细性质。由于这些类星体可能处于快速增长阶段，它们也可能处于强烈的恒星爆发阶段，并且可能具有非常丰富的分子气体。为了观察它，我们对其中一个做了CO观测。事实证明，该天体并不是非常富含气体。3)局部宇宙中窄线塞弗特1星系中的黑洞被认为正在迅速增长，并处于活动星系核的非常年轻的阶段。为了研究气体对黑洞的补充机制，对宿主星系的形态进行了研究。结果表明，条状星系的比例很高，这表明条状结构是气体补充的原因。如果黑洞快速增长，那么中央区域的恒星形成可能也在积极地形成恒星。对窄线塞弗特1星系进行了联合观测，但没有发现明确的协同演化证据。从这些结果可以看出，从宇宙演化的角度来看，黑洞生长得更早，同时协同进化并不是以相同的时间尺度发生的。

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.