We present 1D numerical simulations, which consider the effects of radiative cooling and gravity on the hydrodynamics of the matter reinserted by stellar winds and supernovae within young nuclear starbursts with a central supermassive black hole (SMBH). The simulations confirm our previous semi-analytic results for low energetic starbursts, evolving in a quasi-adiabatic regime, and extend them to more powerful starbursts evolving in the catastrophic cooling regime. The simulations show a bimodal hydrodynamic solution in all cases. They present a quasi-stationary accretion flow onto the black hole, defined by the matter reinserted by massive stars within the stagnation volume and a stationary starburst wind, driven by the high thermal pressure acquired in the region between the stagnation and the starburst radii. In the catastrophic cooling regime, the stagnation radius rapidly approaches the surface of the starburst region, as one considers more massive starbursts. This leads to larger accretion rates onto the SMBH and concurrently to powerful winds able to inhibit interstellar matter from approaching the nuclear starburst.
Our self-consistent model thus establishes a direct physical link between the SMBH accretion rate and the nuclear star formation activity of the host galaxy and provides a good upper limit to the accretion rate onto the central black hole.
Mass and metal ejection efficiency in disk galaxies driven by young stellar clusters of nuclear starburst
我们目前的结果从模型驱动的能量注入核星爆的星系风。星暴的总能量由年轻的中心星团提供,部分银河星际介质作为银河风的一部分被推出(在某些情况下,银河风包含新一代恒星产生的金属的重要部分)。我们已经进行了绝热和辐射的三维N体/光滑粒子流体动力学模拟银河风使用GADGET-2代码。数值模型涵盖了大范围的恒星暴(从$\sim10^2$到$\sim10^7$ M $_\odot$)和星系气体质量(从$\sim6\times10^6$到$\sim10^{11}$ M $_\odot$)。集中的中央星暴区是星系中产生质量和金属损失的有效引擎,也是驱动星系中金属重新分布的有效引擎。
A Large Population of Massive Compact Post-Starburst Galaxies at z>1: Implications for the Size Evolution and Quenching Mechanism of Quiescent Galaxies
我们通过一个0<z<2的年轻和年老静止星系样本的数密度和结构演化来研究红色序列的增长。这些星系是从宇宙演化巡天(COSMOS)领域的NEWFIRM中带巡天(NMBS)中选出的。我们发现了大量的大质量年轻星系,这些星系在z>1时刚刚熄灭(“后星爆”),而在z<1时几乎不存在;它们的数密度在z=2时为5 x 10^{-5} Mpc^{-3},而在z=0.5时要小10倍。在z>1时,观测到的年轻和年老静止星系的数密度与一个简单的模型相一致,在这个模型中,所有年老静止星系都曾被认为是后星暴星系。我们发现,总体人口的静止星系有较小的尺寸和略长的形状在较高的红移,与其他最近的研究。有趣的是,最近在1<z<2处淬灭的星系并不比那些红移的老星系大,甚至可能更小。这一结果与静止星系的平均大小的演化主要是由较大的恒星形成星系的连续转变驱动的观点不一致:在这种情况下,最年轻的静止星系也是最大的。相反,合并或其他机制似乎需要解释从z=2到现在的静止星系的大小增长。
The Dance of the Little Red Dots: Spectroscopy of Two Blue Companions at z = 3.9 and 5.5 Reveals Young, Metal-Poor Starbursts Merging with Their LRDs within a Few Hundred Myr
Department of Astronomy, University of Texas, Austin(德克萨斯大学奥斯汀分校天文系);Cosmic Frontier Center, The University of Texas at Austin(德克萨斯大学奥斯汀分校宇宙前沿中心)