What Do Statistics Reveal About the Black Hole versus the Bulge Mass Correlation and Co-evolution?
Chien Y. Peng
备注：
Invited talk, to appear in the Proceedings of the IAU Symposium 267, "Co-Evolution of Central Black Holes and Galaxies", B.M. Peterson, R.S. Somerville, T. Storchi-Bergmann, eds
Observational data show that the correlation between supermassive black holes (MBH) and galaxy bulge (Mbulge) masses follows a nearly linear trend, and that the correlation is strongest with the bulge rather than the total stellar mass (Mgal). With increasing redshift, the ratio Gamma=MBH/Mbulge relative to z=0 also seems to be larger for MBH >~ 10^{8.5} Msol. This study looks more closely at statistics to better understand the creation and observations of the MBH-Mbulge correlation. It is possible to show that if galaxy merging statistics can drive the correlation, minor mergers are responsible for causing a *convergence to linearity* most evident at high masses, whereas major mergers have a central limit convergence that more strongly *reduces the scatter*. This statistical reasoning is agnostic about galaxy morphology. Therefore, combining statistical prediction (more major mergers ==> tighter correlation) with observations (bulges = tightest correlation), would lead one to conclude that more major mergers (throughout an entire merger tree, not just the primary branch) give rise to more prominent bulges. With regard to controversial findings that Gamma increases with redshift, this study shows why the luminosity function (LF) bias argument, taken correctly at face value, strengthens rather than weakens the results. However, correcting for LF bias is unwarranted because the BH mass scale for quasars is bootstrapped to the MBH-Sigma* correlation in normal galaxies at z=0, and quasar-quasar comparisons are internally consistent. In Monte-Carlo simulations, high Gamma objects are "under-merged" galaxies that take longer to converge to linearity via minor mergers. Another evidence that the galaxies are undermassive at z >~ 2 for their MBH is that the quasar hosts are very compact for their expected mass.
ZENS IV. Similar Morphological Changes associated with Mass- and Environment-Quenching, and the Relative importance of Bulge Growth versus the Fading of Disks
The Impact of the Uncertainty in Single-Epoch Virial Black Hole Mass Estimates on the Observed Evolution of the Black Hole - Bulge Scaling Relations
最近的观测黑洞（BH）的球标度关系通常报告正的红移演化，与高红移星系窝藏更多的质量黑洞比预期的本地关系。所有这些研究都集中在宽线类星体的BH质量估计维里估计的基础上单历元谱。由于样本的选择主要基于类星体的光度，黑洞-球丘关系中的宇宙散射引入了一个统计偏差，导致平均而言，在高红移的星系属性下，更大质量的黑洞（Lauer et al. 2007）。我们在这里强调了以前未被充分认识的统计偏差，这是由单历元维里BH质量估计值的不确定性和潜在的（真实的）BH质量函数的形状造成的，这导致平均高估了高质量端的真实BH质量（Shen et al. 2008）。我们证明，后者维里质量偏差可以贡献大量的BH质量在固定的凸起属性，可与劳尔等人观察到的过剩。维里质量偏置与劳尔等人的偏置无关，因此如果这两种偏置都起作用，它们可以在很大程度上（甚至完全）解释在高红移下观测到的BH质量过剩。
