z~6星系盘中的多尺度质量输运：为黑洞提供燃料
Multiscale mass transport in z~6 galactic discs: fueling black holes
摘要：
利用AMR宇宙学流体动力学N体放大模拟方法，利用RAMSES程序，研究了从高红移到$z\sim6$的星系核质量输运过程。由于模拟的动力学范围很大，我们能够研究从$\sim50[kpc]$到$\sim$几个$1[pc]$尺度上的质量吸积过程。我们研究了BH生长到银河系中心的关系与质量输运过程中的雷诺应力和引力应力盘上。这样的方法使我们能够确定的主要质量运输过程中的功能的规模的问题。我们发现，在包括辐射冷却和SNe反馈的模拟中，SMBH在爱丁顿极限下生长一段时间，在整个演化过程中呈现$\langle f_{EDD}\rangle\approx 0.5$。$α$参数由雷诺项$α_R$和$α_R\gg 1$主导。$α$参数的引力部分$α_G$，在高红移时有向星系中心增加的趋势，在半径< $\sim$的值$α_G\sim 1$很少$ 10^1[pc]$对BH燃料的贡献。在扭矩方面，我们还发现，重力有一个越来越多的贡献对银河系中心在早期的时代与混合贡献以上$\sim 100 [pc]$。这种压力梯度和重力势梯度之间的互补工作允许在圆盘上进行有效的质量传输，平均质量吸积率为$\sim$数$1 [M_{\odot}/yr]$。在我们的宇宙学模拟中发现的这些SMBH吸积率水平是所有试图解释红移$6-7$类星体形成的SMBH增长模型所需要的。
英文摘要：
By using AMR cosmological hydrodynamic N-body zoom-in simulations, with the RAMSES code, we studied the mass transport processes onto galactic nuclei from high redshift up to $z\sim6$. Due to the large dynamical range of the simulations we were able to study the mass accretion process on scales from $\sim50[kpc]$ to $\sim$ few $1[pc]$. We studied the BH growth on to the galactic center in relation with the mass transport processes associated to both the Reynolds stress and the gravitational stress on the disc. Such methodology allowed us to identify the main mass transport process as a function of the scales of the problem. We found that in simulations that include radiative cooling and SNe feedback, the SMBH grows at the Eddington limit for some periods of time presenting $\langle f_{EDD}\rangle\approx 0.5$ throughout its evolution. The $α$ parameter is dominated by the Reynolds term, $α_R$, with $α_R\gg 1$. The gravitational part of the $α$ parameter, $α_G$, has an increasing trend toward the galactic center at higher redshifts, with values $α_G\sim 1$ at radii <$\sim$ few $ 10^1[pc]$ contributing to the BH fueling. In terms of torques, we also found that gravity has an increasing contribution toward the galactic center at earlier epochs with a mixed contribution above $\sim 100 [pc]$. This complementary work between pressure gradients and gravitational potential gradients allows an efficient mass transport on the disc with average mass accretion rates of the order $\sim$ few $1 [M_{\odot}/yr]$. These level of SMBH accretion rates found in our cosmological simulations are needed in all models of SMBH growth that attempt to explain the formation of redshift $6-7$ quasars.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
