论文标题
在$ z = 0.026 $的壮观相互作用的矮人银河系对中发现了阻尼的$α$吸收器
Discovery of a damped Ly$α$ absorber originating in a spectacular interacting dwarf galaxy pair at $z = 0.026$
论文作者
论文摘要
我们介绍了在阻尼的$α$吸收（DLA）和HI 21-cm发射中发现的中性气体在银河系的恒星体外发射，这是文献中第一次这样的检测。宇宙紫外线调查与Meerkat吸收线调查之间的联合分析显示，HI桥连接了两个相互作用的矮人星系（log $（m _ {\ text {star}}/\ text {star}}/\ text {m} {m} _ {\ odot} _ {\ odot}） log [$ n $（hi）/cm $^{ - 2} $] $ = 20.60 \ pm 0.05 $ to qSO j2339-5523（$ z _ {\ text {qso}}} = 1.35 $）。在$ d = 6 $和$ 33 $ kpc的冲击参数上，矮星系没有比$ \ $ \ of 0.05l _ {*} $更发光的伴侣。 HI 21厘米的发射在几个相邻梁上在每个光谱通道的2-3 $σ$水平上与DLA在空间上是一致的。但是，没有针对无线电QSO检测到HI 21-CM的吸收。如果背景紫外线和无线电源在空间对齐中，则气体是温暖的或块状的（旋转温度与覆盖因子比率$ t_ {s}/f_ {c}> 1880 $ k）。 VLT-Muse观察结果表明，电离ISM的$α$元素丰度与DLA一致（$ \ $ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\\\ 10 $ 10 $，这表明中性气体信封扰乱ISM气体。这项研究展示了矮人 - 划线相互作用对恒星形成区域以外的中性气体的物理和化学状态的影响。在SKA时代，关节UV和HI 21-CM分析对于将宇宙中性气体含量与星系环境连接起来至关重要。
We present the discovery of neutral gas detected in both damped Ly$α$ absorption (DLA) and HI 21-cm emission outside of the stellar body of a galaxy, the first such detection in the literature. A joint analysis between the Cosmic Ultraviolet Baryon Survey and the MeerKAT Absorption Line Survey reveals an HI bridge connecting two interacting dwarf galaxies (log$(M_{\text{star}}/\text{M}_{\odot}) = 8.5 \pm 0.2$) that host a $z = 0.026$ DLA with log[$N$(HI)/cm$^{-2}$]$ = 20.60 \pm 0.05$ toward the QSO J2339-5523 ($z_{\text{QSO}} = 1.35$). At impact parameters of $d = 6$ and $33$ kpc, the dwarf galaxies have no companions more luminous than $\approx 0.05L_{*}$ within at least $Δv = \pm 300$ km s$^{-1}$ and $d \approx 350$ kpc. HI 21-cm emission is spatially coincident with the DLA at the 2-3$σ$ level per spectral channel over several adjacent beams. However, HI 21-cm absorption is not detected against the radio-bright QSO; if the background UV and radio sources are spatially aligned, the gas is either warm or clumpy (with spin temperature to covering factor ratio $T_{s}/f_{c} > 1880$ K). VLT-MUSE observations demonstrate that the $α$-element abundance of the ionized ISM is consistent with the DLA ($\approx 10$% solar), suggesting that the neutral gas envelope is perturbed ISM gas. This study showcases the impact of dwarf-dwarf interactions on the physical and chemical state of neutral gas outside of star-forming regions. In the SKA era, joint UV and HI 21-cm analyses will be critical for connecting the cosmic neutral gas content to galaxy environments.
