论文标题
从观察的角度来看，z = 2的TNG50星系的运动学和暗物质分数
The Kinematics and Dark Matter Fractions of TNG50 Galaxies at z=2 from an Observational Perspective
论文作者
论文摘要
我们将$ Z = 2 $星形星系（SFG）的气体运动学和暗物质内容物与$λ$ CDM框架内的最先进的宇宙学模拟与观察结果形成鲜明对比。 To this end, we create realistic mock observations of massive SFGs ($M_*>4\times10^{10} M_{\odot}$, SFR $>50~M_{\odot}$ yr$^{-1}$) from the TNG50 simulation of the IllustrisTNG suite, resembling near-infrared, adaptive-optics assisted integral-field从地面观察。使用观测线拟合和建模技术，我们详细分析了从每个星系五个不同投影的七个TNG50星系的运动学，并将它们与Genzel等人的十二个大型SFG进行比较。 （2020）。模拟的星系显示盘式旋转的明显迹象，但大多显示出更多的不对称旋转曲线，部分原因是较大的固有径向和垂直速度成分。在相同的倾斜角度，它们的一维速度曲线可以随着不同的视线而变化，最多可达$ΔV= 200 $ km s $^{ - 1} $。从动态建模中，我们推断出与观察结果广泛一致的旋转速度和速度分散。我们发现低中央暗物质分数与观察值兼容（$ f _ {\ rm dm}^v（<r_e）= v _ {\ rm dm}^2（r_e）/v _ {\ rm circ}^2（r_e）^2（r_e）^2（r_e）\ sim0.32 \ sim0.32 \ pm0.10 $ in Disce $ radi in nise $ radi是有效的RADI。 $ r_e $ TNG50暗物质分数太高了$ \ sim2 $。我们推测，与观察结果相比，气体运动学和暗物质含量的差异可能是由于物理过程与当前宇宙学模拟中可用的数值分辨率无法详细解析的物理过程所致。
We contrast the gas kinematics and dark matter contents of $z=2$ star-forming galaxies (SFGs) from state-of-the-art cosmological simulations within the $Λ$CDM framework to observations. To this end, we create realistic mock observations of massive SFGs ($M_*>4\times10^{10} M_{\odot}$, SFR $>50~M_{\odot}$ yr$^{-1}$) from the TNG50 simulation of the IllustrisTNG suite, resembling near-infrared, adaptive-optics assisted integral-field observations from the ground. Using observational line fitting and modeling techniques, we analyse in detail the kinematics of seven TNG50 galaxies from five different projections per galaxy, and compare them to observations of twelve massive SFGs by Genzel et al. (2020). The simulated galaxies show clear signs of disc rotation but mostly exhibit more asymmetric rotation curves, partly due to large intrinsic radial and vertical velocity components. At identical inclination angle, their one-dimensional velocity profiles can vary along different lines of sight by up to $Δv=200$ km s$^{-1}$. From dynamical modelling we infer rotation speeds and velocity dispersions that are broadly consistent with observational results. We find low central dark matter fractions compatible with observations ($f_{\rm DM}^v(<R_e)=v_{\rm DM}^2(R_e)/v_{\rm circ}^2(R_e)\sim0.32\pm0.10$), however for disc effective radii $R_e$ that are mostly too small: at fixed $R_e$ the TNG50 dark matter fractions are too high by a factor of $\sim2$. We speculate that the differences in gas kinematics and dark matter content compared to the observations may be due to physical processes that are not resolved in sufficient detail with the numerical resolution available in current cosmological simulations.
