论文标题
Lyman alpha参考样品XI：有效的湍流驱动的LYα逃逸和IR，CO和[C II]158μm的分析
The Lyman Alpha Reference Sample XI: Efficient Turbulence Driven Lyα Escape and the Analysis of IR, CO and [C II]158 μm
论文作者
论文摘要
我们研究了Lyman Alpha参考样品（LARS）中的全球粉尘和（分子）气体含量，即14个局部恒星形成星系。我们表征了它们的星际介质，并将新得出的特性与与Ly $ ly $α$逃生相关的数量相关联。我们观察到LARSHEL/PACS，SOFIA/FIFI-LS，IRAM 300M望远镜和Apex，靶向[C II] 158 $μ$ M，[O I] 63 $ M $ M，[O III] 88 $ M $ M $ M $ M $ M $ M M和Low-J Co Co Line [C II] 158 $ $ m，[o I] 63 $ M，[O I] 63 $ M，[O I] 63 $ M，[O I] 63 $ M，[O I] 63 $ M，[o I] 63 $ M，[O I]）的排放线。使用贝叶斯方法，我们考虑了金属依赖性的气体与尘埃比，我们得出了所有LARS星系的灰尘模型参数，并估算所有LARS星系的总气体质量。恒星形成率是从FIR，[C II] 158 $μ$ m和[O I] 63 $μ$ m的发光量估算的。 LARS涵盖了派生性属性的广泛动态范围，基于FIR的星星的形成率从$ \ sim $ 0.5-100 $ M _ {\ odot} \ yr^{ - 1} $，$ \ sim $ 15-80％和气体耗尽时间之间的气体分数范围从几百myr到几百Myr到10 gyr。因此，Lars星系在$σ_{gas} $ vs. $σ_{sfr} $（kennicutt-schmidt平面）中的分布非常异构。但是，我们发现，气体耗尽时间最长的LARS星系，即相对较高的气体表面密度（$σ_{gas} $）和低恒星形成速率密度（$σ_{sfr} $）的最高$ ly $ ly $α$逃逸分数。在LY $α$逃生分数和总气体（HI+H $ _2 $）耗尽时间之间发现了强大的$ \ sim $线性关系。我们认为，这些星系中的Ly $α$逃逸是由星形的气体中的湍流驱动的，该气体的湍流使Ly $α$光子从靠近它们起源的地方的共振中移出。我们进一步报告了极限[C II] 158 $μ$ m在LARS 5中的过剩，对应于$ \ sim $ 14 $ \ pm $ 3％的FIR光度，即迄今为止在非AGN Galaxy中观察到的最极端的[C II] fir比率。
We study the global dust and (molecular) gas content in the Lyman Alpha Reference Sample (LARS), i.e. 14 local star-forming galaxies. We characterize their interstellar medium and relate newly derived properties to quantities relevant for Ly$α$ escape. We observed LARS galaxies with Herschel/PACS, SOFIA/FIFI-LS, the IRAM 30m telescope and APEX, targeting far-infrared (FIR) continuum and emission lines of [C II]158$μ$m, [O I]63$μ$m, [O III]88$μ$m and low-J CO lines. Using Bayesian methods we derive dust model parameters and estimate total gas masses for all LARS galaxies, taking into account a metallicity-dependent gas-to-dust ratio. Star formation rates were estimated from FIR, [C II]158$μ$m and [O I]63$μ$m luminosities. LARS covers a wide dynamic range in the derived properties, with FIR-based star formation rates from $\sim$0.5-100 $M_{\odot}\ yr^{-1}$, gas fractions between $\sim$15-80% and gas depletion times ranging from a few hundred Myr up to more than 10 Gyr. The distribution of LARS galaxies in the $Σ_{gas}$ vs. $Σ_{SFR}$ (Kennicutt-Schmidt plane) is thus quite heterogeneous. However, we find that LARS galaxies with the longest gas depletion times, i.e. relatively high gas surface densities ($Σ_{gas}$) and low star formation rate densities ($Σ_{SFR}$), have by far the highest Ly$α$ escape fraction. A strong $\sim$linear relation is found between Ly$α$ escape fraction and the total gas (HI+H$_2$) depletion time. We argue that the Ly$α$ escape in those galaxies is driven by turbulence in the star-forming gas that shifts the Ly$α$ photons out of resonance close to the places where they originate. We further report on an extreme [C II]158$μ$m excess in LARS 5, corresponding to $\sim$14$\pm$3% of the FIR luminosity, i.e. the most extreme [C II]-to-FIR ratio observed in a non-AGN galaxy to date.
