论文标题
恒星角动量与附近磁盘为主导星系中恒星质量之间的关系的起源
The Origin of the Relation Between Stellar Angular Momentum and Stellar Mass in Nearby Disk-dominated galaxies
论文作者
论文摘要
Illustristng模拟重现了中央星系的恒星特定角动量（SAM）$ J _ {\ rm S} $和质量$ M _ {\ rm S} $之间观察到的缩放关系。我们表明，本地$ j _ {\ rm s} $ - $ m _ {\ rm s} $关系$ {\ rm log} \ j _ {\ rm s} = 0.55 \ \ rm log {\ rm log}我们提供了一个简单的模型，该模型很好地描述了光环和星系之间的这种联系。 $ j _ {\ rm s} $ - $ m _ {\ rm s} $的索引0.55来自$ j _ {\ rm tot} \ propto m _ {\ rm topto m _ {\ rm tot}^0.81}^{0.81} $，$ M _ {\ rm m _ { s}^{0.67} $，和$ j _ {\ rm s} \ propto j _ {\ rm tot} $关系，其中$ j _ {\ rm tot} $和$ m _ {\ rm tot} $是SAM和HALO的整体SAM和质量。应包括$ j _ {\ rm tot} \ propto m _ {\ rm tot}^{2/3} $的潮汐扭矩理论的不可忽略的偏差。该模型进一步表明，磁盘星系的恒星与半升高的质量比单调地增加了与最新动力学测量相一致的几乎幂律函数。偏置的塌陷，其中来自其父置晕内部和下SAM部分形成星系，在低红移时产生了较小的影响。角动量的保留因子达到$ \ sim 1 $的磁盘星系中，并具有很强的旋转，并且与球体成分的质量分数相反，这部分解释了$ j _ {\ rm s} $ - $ m _ {\ $ m _ {\ rm s s} $相关性的形态依赖性。
The IllustrisTNG simulations reproduce the observed scaling relation between stellar specific angular momentum (sAM) $j_{\rm s}$ and mass $M_{\rm s}$ of central galaxies. We show that the local $j_{\rm s}$-$M_{\rm s}$ relation ${\rm log}\ j_{\rm s} = 0.55 \ {\rm log}\ M_{\rm s} + 2.77$ develops at $z\lesssim 1$ in disk-dominated galaxies. We provide a simple model that describes well such a connection between halos and galaxies. The index 0.55 of the $j_{\rm s}$-$M_{\rm s}$ relation comes from the product of the indices of the $j_{\rm tot}\propto M_{\rm tot}^{0.81}$, $M_{\rm tot}\propto M_{\rm s}^{0.67}$, and $j_{\rm s}\propto j_{\rm tot}$ relations, where $j_{\rm tot}$ and $M_{\rm tot}$ are overall sAM and mass of a halo. A non-negligible deviation from the tidal torque theory, which predicts $j_{\rm tot}\propto M_{\rm tot}^{2/3}$, should be included. This model further suggests that the stellar-to-halo mass ratio of disk galaxies increases monotonically following a nearly power-law function that is consistent with the latest dynamical measurements. Biased collapse, in which galaxies form from the inner and lower sAM portion of their parent halos, has a minor effect at low redshifts. The retention factor of angular momentum reaches $\sim 1$ in disk galaxies with strong rotations, and it correlates inversely with the mass fraction of the spheroidal component, which partially explains the morphological dependence of the $j_{\rm s}$-$M_{\rm s}$ relation.
