论文标题

LEGA-C:分析来自Z〜0.8的电离气体和恒星运动学的动力质量

LEGA-C: analysis of dynamical masses from ionized gas and stellar kinematics at z~0.8

论文作者

Straatman, Caroline M. S., van der Wel, Arjen, van Houdt, Josha, Bezanson, Rachel, Bell, Eric F., van Dokkum, Pieter, D'Eugenio, Francesco, Franx, Marijn, Gallazzi, Anna, de Graaff, Anna, Maseda, Michael, Meidt, Sharon E., Muzzin, Adam, Sobral, David, Wu, Po-Feng

论文摘要

我们比较基于空间扩展的恒星和离子化气体运动学($ \ MATHRM {m_ {dyn,*}} $和$ \ mathrm {m_ mathrm {m_ mathrm {m_ {mathrm {m_ {dyn,eml}} $),为157 star成立星系的$ 0.6 \ leq leq z <1 $。与$ z \ sim0 $相比,这些星系具有增强的恒星形成率,恒星反馈可能会影响气体的动态。我们使用Lega-C DR3,这是最高的红移数据集,提供了$ k_s- $ band Limited样品的足够深度测量。对于$ \ mathrm {m_ {dyn,*}} $,我们使用牛仔裤各向异性多高斯扩展模型。对于$ \ mathrm {m_ {dyn,eml}} $,我们首先拟合具有统一分散的旋转指数磁盘的自定义模型,其光线通过缝隙投射并校正了光束涂抹。然后,我们将基于文献中常见的假设的不对称漂移校正应用于拟合的运动学成分,以获得循环速度,假设静水平衡。在半光半径内,$ \ mathrm {m_ {dyn,eml}} $平均低于$ \ mathrm {m_ {m_ {dyn,*}} $,平均偏移$ -0.15 \ pm0.016 $ dex $ dex和galaxy-to-to-dex and Galaxy-to-galaxy-to castecty astection $ 0.19 $ 0.19 $ dex $ dex $ dex,反映的commented compented compented compented compented compinded compented compented compented compented compented。虽然需要较高空间分辨率的数据来了解这一较小的偏移,但它支持以下假设:范围范围的电离气体运动学并非主要来自诸如恒星形成驱动的外流之类的破坏性事件。但是,可以在不从轴比率$ q <0.8 $的集成排放线分散体中进行建模而获得类似的协议。这表明,与缺少空间扩展动力学所需的$ S/N $相比,我们目前对气体运动学的理解不足以有效地应用不对称的漂移校正来改善动力学质量估计。

We compare dynamical mass estimates based on spatially extended stellar and ionized gas kinematics ($\mathrm{M_{dyn,*}}$ and $\mathrm{M_{dyn,eml}}$, respectively) of 157 star forming galaxies at $0.6\leq z<1$. Compared to $z\sim0$, these galaxies have enhanced star formation rates, with stellar feedback likely affecting the dynamics of the gas. We use LEGA-C DR3, the highest redshift dataset providing sufficiently deep measurements of a $K_s-$band limited sample. For $\mathrm{M_{dyn,*}}$ we use Jeans Anisotropic Multi-Gaussian Expansion models. For $\mathrm{M_{dyn,eml}}$ we first fit a custom model of a rotating exponential disk with uniform dispersion, whose light is projected through a slit and corrected for beam smearing. We then apply an asymmetric drift correction based on assumptions common in the literature to the fitted kinematic components to obtain the circular velocity, assuming hydrostatic equilibrium. Within the half-light radius, $\mathrm{M_{dyn,eml}}$ is on average lower than $\mathrm{M_{dyn,*}}$, with a mean offset of $-0.15\pm0.016$ dex and galaxy-to-galaxy scatter of $0.19$ dex, reflecting the combined random uncertainty. While data of higher spatial resolution are needed to understand this small offset, it supports the assumption that the galaxy-wide ionized gas kinematics do not predominantly originate from disruptive events such as star formation driven outflows. However, a similar agreement can be obtained without modeling from the integrated emission line dispersions for axis ratios $q<0.8$. This suggests that our current understanding of gas kinematics is not sufficient to efficiently apply asymmetric drift corrections to improve dynamical mass estimates compared to observations lacking the $S/N$ required for spatially extended dynamics.

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