标题： 宇宙学21厘米线观测以检验黑洞作为高红移超大质量黑洞种子的超爱丁顿吸积情景 显示英文标题

标题： Cosmological 21cm line observations to test scenarios of super-Eddington accretion on to black holes being seeds of high-redshifted supermassive black holes

摘要： 在本文中，我们研究了高红移处黑洞的超爱丁顿吸积情景$z > 10$，这些情景被认为是演变为超大质量黑洞直到红移$z \sim 7$的种子。 对于种子黑洞的初始质量，$M_{\rm BH, ini} \lesssim 2 \times 10^{3} M_{\odot}$，我们肯定需要超爱丁顿吸积，这适用于天体物理和原初起源。 这种吸积盘不可避免地发射出高能光子，这些光子从高红移持续加热了星系间介质的宇宙等离子体。 在这种情况下，宇宙气体温度的宇宙历史被修改，从而抑制了宇宙21厘米线的吸收特征。 通过将21厘米线吸收的理论预测与红移$z\sim17$的观测数据进行比较，我们得到了一个质量吸积率的宇宙上限，该上限是种子黑洞质量的函数。 为了在$z \sim 7$上通过连续质量吸积实现$M_{\rm BH} \sim 10^9 M_{\odot}$，以与宇宙学 21cm 线吸收在$z \sim 17$一致，当我们假设种子黑洞的共动数密度为$n_{\rm seed,0} \sim 10^{-3} {\rm Mpc}^{-3}$($n_{\rm seed,0} \sim 10^{-7} {\rm Mpc}^{-3}$) 时，我们得到了种子黑洞初始质量的严格上限为$M_{\rm BH, ini} \lesssim 10^2 M_{\odot}$($M_{\rm BH, ini} \lesssim 10^6 M_{\odot}$)。 我们还讨论了将原初黑洞作为种子黑洞应用的一些含义。 显示英文摘要

摘要： In this paper, we study scenarios of the super-Eddington accretion onto black holes at high redshifts $z > 10$, which are expected to be seeds to evolve to supermassive black holes until redshift $z \sim 7$. For an initial mass, $M_{\rm BH, ini} \lesssim 2 \times 10^{3} M_{\odot}$ of a seed BH, we definitely need the super-Eddington accretion, which can be applicable to both astrophysical and primordial origins. Such an accretion disk inevitably emitted high-energy photons which had heated the cosmological plasma of the inter-galactic medium continuously from high redshifts. In this case, the cosmic history of cosmological gas temperature is modified, by which the absorption feature of the cosmological 21 cm lines is suppressed. By comparing theoretical predictions of the 21cm line absorption with the observational data at $z\sim17$, we obtain a cosmological upper bound on the mass-accretion rate as a function of the seed BH masses. In order to realize $M_{\rm BH} \sim 10^9 M_{\odot}$ at $z \sim 7$ by a continuous mass-accretion on to a seed BH, to be consistent with the cosmological 21cm line absorption at $z \sim 17$, we obtained an severe upper bound on the initial mass of the seed BH to be $M_{\rm BH, ini} \lesssim 10^2 M_{\odot}$ ($M_{\rm BH, ini} \lesssim 10^6 M_{\odot}$) when we assume a seed BH with its comoving number density $n_{\rm seed,0} \sim 10^{-3} {\rm Mpc}^{-3}$ ($n_{\rm seed,0} \sim 10^{-7} {\rm Mpc}^{-3}$). We also discuss some implications for application to primordial black holes as the seed black holes.