论文标题
宇宙紫外线调查（Cubs）II：发现H $ _ {2} $ - 在Z = 0.576的早期型星系附近轴承DLA
The Cosmic Ultraviolet Baryon Survey (CUBS) II: Discovery of an H$_{2}$-Bearing DLA in the Vicinity of an Early-Type Galaxy at z = 0.576
论文作者
论文摘要
我们报告了h $ _ {2} $的偶然检测 - 在宇宙紫外线重测调查中，在QSO J0111-0316的频谱中，Z = 0.576的轴承damped lyman- $α$吸收器在z = 0.576。来自远离紫外线中HST-COS的光谱观察结果揭示了一个受阻尼吸收器，具有log [n（hi）/cm^-2] = 20.1 +/- 0.2和log [n（h $ _ {2} $）/cm^-2] = 18.97（-0.06，106， +0.05）。弥漫性分子气是在两个速度分量中发现的，dv = 60 km/s，> 99.9％的总H $ _ {2} $列列密度集中在一个组件中。以$ \ $ \ $ 50％的太阳能的金属性，有证据表明Fe增强和灰尘耗尽，灰尘与气体比$κ_ {\ text {o}} \ your $ 0.4。在麦哲伦上使用iMac和LDSS-3C进行的一项星系红移调查显示，在投影距离d <= 600适当的kPC（PKPC）和视线速度偏移量DV $ _ {G} $ <= 300 km/s的过度密度为900个适当的KPC（PKPC）和视线速度偏移。最接近的是D = 41 PKPC的庞大的早期类型星系，其中包含$ \ $ \ $ 70％的$ 70％，占H $ _ {2} $ pabsorber的d <= 310 pkpc的总恒星质量。 H $ _ {2} $ - 轴承气体与静态星系的近距离近距离，吸收剂的Fe-Enhanced化学丰度模式表明了物理联系，与DLA的图片相反，DLA主要与富含气体的小矮人相关。该案例研究表明，需要深层红移调查，以深入了解具有富含浓密且潜在的恒星形成气体的各种环境。
We report the serendipitous detection of an H$_{2}$-bearing damped Lyman-$α$ absorber at z = 0.576 in the spectrum of the QSO J0111-0316 in the Cosmic Ultraviolet Baryon Survey. Spectroscopic observations from HST-COS in the far-ultraviolet reveal a damped absorber with log[N(HI)/cm^-2] = 20.1 +/- 0.2 and log[N(H$_{2}$)/cm^-2] = 18.97 (-0.06, +0.05). The diffuse molecular gas is found in two velocity components separated by dv = 60 km/s, with >99.9% of the total H$_{2}$ column density concentrated in one component. At a metallicity of $\approx$ 50% of solar, there is evidence for Fe enhancement and dust depletion, with a dust-to-gas ratio $κ_{\text{O}} \approx$ 0.4. A galaxy redshift survey conducted with IMACS and LDSS-3C on Magellan reveals an overdensity of nine galaxies at projected distance d <= 600 proper kpc (pkpc) and line-of-sight velocity offset dv$_{g}$ <= 300 km/s from the absorber. The closest is a massive, early-type galaxy at d = 41 pkpc which contains $\approx$ 70% of the total stellar mass identified at d <= 310 pkpc of the H$_{2}$ absorber. The close proximity of the H$_{2}$-bearing gas to the quiescent galaxy and the Fe-enhanced chemical abundance pattern of the absorber suggest a physical connection, in contrast to a picture in which DLAs are primarily associated with gas-rich dwarfs. This case study illustrates that deep galaxy redshift surveys are needed to gain insight into the diverse environments that host dense and potentially star-forming gas.
