论文标题
哈勃参数对第一个类星体宇宙生长的影响
Effects of the Hubble Parameter on the Cosmic Growth of the First Quasars
论文作者
论文摘要
超大质黑洞（SMBHS）在星系的演变中起着至关重要的作用，目前被检测到$ z \ sim 7.5 $。描述黑洞（BH）增长的理论受到初始质量$ M _ {\ bullet} \ Lessim 10^5 \，\ Mathrm {m _ {\ odot}} $的迅速质疑，以$ z \ sim \ sim 20-30 $形成，grew至$ m _ { \ Mathrm {m _ {\ odot}} $ by $ z \ sim 7 $。在这里，我们研究了哈勃参数价值$ H_0 $的影响，对描述BHS早期增长的模型。首先，我们注意到，如果模型中使用的基础哈勃参数从$ H_0 = 65 $到$ h_0 = 74 $ km s $ s $ s $ s $^{ - 1} $ MPC $^{ - 1} $，则预测的$ z = 6 $更改为$> 300 $％％。我们采用基于$ z \ gtrsim 6.5 $ quasars和$ h_0 $的MCMC方法，我们研究了$ H_0 $与描述BH增长的参数之间的互连：种子质量$ M_I $和Eddington Ratio $ f _ {\ rmEdd} $。假设$ f _ {\ rm edd} = 0.7 $的爱丁顿比率与以前的估计一致，我们发现$ h_0 = 73.6^{+1.2} _ { - 3.3} $ s $ s $ s $ s $^{ - 1} $ mpc $^{ - 1} $。在第二个分析中，允许所有参数自由变化，我们找到$ \ log（m_ {i}/\ mathrm {m _ {\ odot}}）> 4.5 $（在95％Cl），$ h_0 = 74 = 74 = 74^{+1.5} {+1.5} $ f _ {\ rm edd} = 0.77^{+0.035} _ { - 0.026} $ 68％Cl。我们关于典型的爱丁顿比率的结果与以前的估计一致。哈勃参数的当前值强烈偏爱重种子形成方案，其中$ m_i \ gtrsim 10^4 \，\ mathrm {m _ {\ odot}} $。在我们的模型中，使用使用的类品牌BH质量的先验，在$ \ sim3σ$上拒绝了浅种子形成方案。
Supermassive black holes (SMBHs) play a crucial role in the evolution of galaxies and are currently detected up to $z\sim 7.5$. Theories describing black hole (BH) growth are challenged by how rapidly seeds with initial mass $M_{\bullet} \lesssim 10^5 \, \mathrm{M_{\odot}}$, formed at $z \sim 20-30$, grew to $M_{\bullet} \sim 10^9 \, \mathrm{M_{\odot}}$ by $z\sim 7$. Here we study the effects of the value of the Hubble parameter, $H_0$, on models describing the early growth of BHs. First, we note that the predicted mass of a quasar at $z=6$ changes by $> 300$% if the underlying Hubble parameter used in the model varies from $H_0 = 65$ to $H_0 = 74$ km s$^{-1}$Mpc$^{-1}$, a range encompassing current estimates. Employing an MCMC approach based on priors from $z \gtrsim 6.5$ quasars and on $H_0$, we study the interconnection between $H_0$ and the parameters describing BH growth: seed mass $M_i$ and Eddington ratio $f_{\rm Edd}$. Assuming an Eddington ratio of $f_{\rm Edd} = 0.7$, in agreement with previous estimates, we find $H_0 = 73.6^{+1.2}_{-3.3}$ km s$^{-1}$Mpc$^{-1}$. In a second analysis, allowing all the parameters to vary freely, we find $\log(M_{i}/\mathrm{M_{\odot}}) > 4.5$ (at 95% CL), $H_0 = 74^{+1.5}_{-1.4}$ km s$^{-1}$Mpc$^{-1}$ and $f_{\rm Edd}=0.77^{+0.035}_{-0.026}$ at 68% CL. Our results on the typical Eddington ratio are in agreement with previous estimates. Current values of the Hubble parameter strongly favour heavy seed formation scenarios, with $M_i \gtrsim 10^4 \, \mathrm{M_{\odot}}$. In our model, with the priors on BH masses of quasars used, light seed formation scenarios are rejected at $\sim 3σ$.
