论文标题
黑洞质量露出平面中Z〜6种子的人口统计
Demographics of z ~ 6 Quasars in the Black Hole Mass-Luminosity Plane
论文作者
论文摘要
我们使用5.7 <z <6.5的100多个类星体样本研究了黑洞（BH）质量亮度平面中Z〜6宽线类星体的人口统计。这些类星体具有量化的选择功能，其中近三分之一还具有从近IR光谱法估计的病毒BH质量。我们使用BH质量和爱丁顿比率的参数化固有分布的正向建模，并考虑了BH质量和亮度的样品通量极限和测量不确定性。我们发现，由于测量不确定性和样品通量极限，固有和观察到的分布之间存在显着差异。也有边际证据表明，病毒BH质量易于依赖阳光度偏差（当亮度高于平均水平时，BH质量被高估了），并且均值Eddington比率随BH质量而增加。我们的模型在M_BH> 10^8.5 m_sun上对Z〜6黑洞质量函数提供了可靠的约束，中位数1- sigma不确定性为〜0.5 dex。 M_BH> 10^8.5 m_sun类星体的内在爱丁顿比率分布可以通过质量依赖的schechter模型近似，围绕log（l_bol/l_edd}）〜 -0.9，其较大峰。我们还发现，在4.5 <z <6时，随着红移的增加，较大的BHS的数量往往会更快地下降，这与先前报道的2.5 <z <4.5趋势相反。
We study the demographics of z ~ 6 broad-line quasars in the black hole (BH) mass-luminosity plane using a sample of more than 100 quasars at 5.7 < z < 6.5. These quasars have well quantified selection functions and nearly one third of them also have virial BH masses estimated from near-IR spectroscopy. We use forward modeling of parameterized intrinsic distributions of BH masses and Eddington ratios, and account for the sample flux limits and measurement uncertainties of the BH masses and luminosities. We find significant differences between the intrinsic and observed distributions of the quantities due to measurement uncertainties and sample flux limits. There is also marginal evidence that the virial BH masses are susceptible to a positive luminosity-dependent bias (BH mass is overestimated when luminosity is above the average), and that the mean Eddington ratio increases with BH mass. Our models provide reliable constraints on the z ~ 6 black hole mass function at M_BH > 10^8.5 M_Sun, with a median 1-sigma uncertainty of ~0.5 dex in abundance. The intrinsic Eddington ratio distribution of M_BH > 10^8.5 M_Sun quasars can be approximated by a mass-dependent Schechter model, with a broad peak around log(L_bol/L_Edd}) ~ -0.9. We also find that, at 4.5 < z < 6, the number densities of more massive BHs tend to decline more rapidly with increasing redshift, contrary to the trend at 2.5 < z < 4.5 reported previously.
