论文标题
高红移黑洞的大容量组装
The mass assembly of high-redshift black holes
论文作者
论文摘要
我们使用Delphi半分析模型来研究在广泛的质量范围内高红移（$ z> 4 $）黑洞的质量组装和特性，$ 10^3 <m_ {bh}/m_ \ odot <10^{10^{10} $。我们的黑洞生长实施包括一个关键的光环质量（$ M_ {h}^{Crit} $），在该质量下，黑洞饿了，在该量之上允许其在Eddington限制或与银河系的气体含量成比例地生长。 As a consequence, after an initial growth phase dominated by black hole mergers down to $z \sim 7 (9)$, supermassive black holes in $z=4$ halo masses of $M_h|_{z=4} \sim 10^{11.75} ~ (10^{13.4}) M_\odot$ mainly grow by gas accretion from the interstellar medium.特别是，我们发现：（i）大多数积分发生在主要分支中，以$ M_H | _ | _ {z = 4} \ SIM 10^{11-12} M_ \ ODOT $ HAROS，但辅助分支中的增值在组装Black Hole Moss Halos中起着重要作用（$ M_H | M_H | MM_H | _H | _ Holes thabor） m_ \ odot $）; （ii）尽管低质量（$ m_ {bh} <10^5 m_ \ odot $）的黑孔的红移降低时，爱丁顿的比例会增加，但它显示了较大质量的相反趋势。此外，由于积聚速率取决于宿主光环中存在的气体质量，因此爱丁顿限制的积聚阶段的占空比（可以持续到$ \ 650 $ myr）与黑洞及其宿主卤素的联合组装历史至关重要。
We use the Delphi semi-analytic model to study the mass assembly and properties of high-redshift ($z>4$) black holes over a wide mass range, $10^3 < M_{bh}/M_\odot < 10^{10}$. Our black hole growth implementation includes a critical halo mass ($M_{h}^{crit}$) below which the black hole is starved and above which it is allowed to grow either at the Eddington limit or proportionally to the gas content of the galaxy. As a consequence, after an initial growth phase dominated by black hole mergers down to $z \sim 7 (9)$, supermassive black holes in $z=4$ halo masses of $M_h|_{z=4} \sim 10^{11.75} ~ (10^{13.4}) M_\odot$ mainly grow by gas accretion from the interstellar medium. In particular, we find that: (i) while most of the accretion occurs in the major branch for $M_h|_{z=4} \sim 10^{11-12} M_\odot$ halos, accretion in secondary branches plays a significant role in assembling the black hole mass in higher-mass halos ($M_h|_{z=4} \gtrsim 10^{12} M_\odot$); (ii) while the Eddington ratio increases with decreasing redshift for low-mass ($M_{bh} < 10^5 M_\odot$) black holes, it shows the opposite trend for larger masses. In addition, since the accretion rate depends on the gas mass present in the host halo, the duty cycle of the Eddington-limited accretion phase -- which can last up to $\approx 650$ Myr -- is crucially linked to the joint assembly history of the black hole and its host halo.
