论文标题
浴缸中的大象：当恒星形成的物理学调节星系的重子循环时
The Elephant in the Bathtub: when the physics of star formation regulate the baryon cycle of galaxies
论文作者
论文摘要
在简单的星系形成和进化的模型中，恒星形成仅受星系中存在的气体量调节。然而，最近已经显示，星系中的银河系动力学可以抑制恒星形成，该星系中包含主要球体成分和低气分。假设这种“动力抑制”也有助于高红移时淬火富含气体的星系，但它对整个星系人群的影响尚不清楚。在本文中，我们通过对分离的星系的流体动力学模拟对星系进化的气体调节剂模型进行动力抑制的重要性，气体与恒星质量比为0.01-0.20，以及从盘状旋转到粒子的一系列银河重力电位。恒星形成是使用每个自由下落时间的动力学依赖性效率来建模的，这取决于气体的病毒参数。我们发现，动态抑制在较低的气体分数上变得更加有效，并量化其对气体形成速率的影响是气体分数和恒星球体质量表面密度的函数。我们将模拟的结果与观察到的缩放关系结合在一起，这些缩放关系描述了跨宇宙时间的星系性能的变化，并确定了动态抑制可能影响巴里昂循环的星系质量和红移范围。我们预测，在低红移（$ z \ Lessim 1.4 $）和高星系块（$ M _ {\ ast} \ gtrsim 3 \ times 10^{10} {10} 〜m _ {\ odot} $）上，动态的供应量可以驱动星形序列形式。
In simple models of galaxy formation and evolution, star formation is solely regulated by the amount of gas present in the galaxy. However, it has recently been shown that star formation can be suppressed by galactic dynamics in galaxies that contain a dominant spheroidal component and a low gas fraction. This 'dynamical suppression' is hypothesised to also contribute to quenching gas-rich galaxies at high redshift, but its impact on the galaxy population at large remains unclear. In this paper, we assess the importance of dynamical suppression in the context of gas regulator models of galaxy evolution through hydrodynamic simulations of isolated galaxies, with gas-to-stellar mass ratios of 0.01-0.20 and a range of galactic gravitational potentials from disc-dominated to spheroidal. Star formation is modelled using a dynamics-dependent efficiency per free-fall time, which depends on the virial parameter of the gas. We find that dynamical suppression becomes more effective at lower gas fractions and quantify its impact on the star formation rate as a function of gas fraction and stellar spheroid mass surface density. We combine the results of our simulations with observed scaling relations that describe the change of galaxy properties across cosmic time, and determine the galaxy mass and redshift range where dynamical suppression may affect the baryon cycle. We predict that the physics of star formation can limit and regulate the baryon cycle at low redshifts ($z \lesssim 1.4$) and high galaxy masses ($M_{\ast} \gtrsim 3 \times 10^{10}~M_{\odot}$), where dynamical suppression can drive galaxies off the star formation main sequence.
