标题： MUSEQuBES：低红移星系周围冷HI气体的柱密度、覆盖分数、质量及环境依赖性 显示英文标题

标题： MUSEQuBES: The Column Density, Covering Fraction, Mass, and Environmental Dependence of Cool HI Gas Around Low-Redshift Galaxies

摘要： 我们通过MUSE类星体场盲发射者调查（MUSEQuBES）使用15个背景类星体（中位撞击参数，D ~ 140物理千帕克（pkpc）），研究了256个星系（中位恒星质量，log10(M*/Msun) = 8.7，中位红移，z = 0.48）附近由莱曼系列吸收所追踪的冷HI气体。我们发现，围绕孤立的、正在形成恒星的星系（跨越约3个数量级的恒星质量）的HI柱密度（N(HI)）分布，当以归一化的撞击参数D/Rvir为函数时，可以用斜率为~ -2.3的幂律很好地描述。对于阈值为log10(N(HI)/cm^{-2}) = 14的HI覆盖分数（k），在晕半径内，高质量被动星系的k值显著低于其孤立的、正在形成恒星的对应星系。孤立的、正在形成恒星的星系的k分布表明，富含HI的CGM特征尺寸约为1.5 Rvir，在恒星质量范围内一致。外CGM（0.3-1 Rvir）中的平均HI质量随着恒星质量的增加而增加，范围从~ 10^{5}到10^{6.6}Msun。最强HI组分的b参数分别与特定恒星形成率（sSFR）和质量相关和反相关，具有> 2 sigma的显著性。b > 60 km s^{-1}的宽Lya吸收体（BLAs）主要与高质量星系相关，可能追踪CGM的温暖-热相。HI组分的速度中心表明，D < Rvir处的吸收体基本上与它们相关的星系引力束缚，无论恒星质量如何。最后，利用来自六个MUSEQuBES区域广域Magellan后续观测的约3000个光谱红移星系，我们发现非孤立星系表现出一个富含HI的环境，其延伸范围大约是其孤立对应星系的三倍。 显示英文摘要

摘要： We investigate cool HI gas traced by Lyman series absorption in the vicinity of 256 galaxies (median stellar mass, log10(M*/Msun) = 8.7 and median redshift, z = 0.48) using 15 background quasars (median impact parameter, D ~ 140 physical kpc (pkpc)), as part of the MUSE Quasar-fields Blind Emitters Survey (MUSEQuBES). We find that the HI column density (N(HI)) profile around isolated, star-forming galaxies, which span ~ 3 dex in stellar mass, is well described by a power law with a slope of ~ -2.3 when expressed as a function of the normalized impact parameter, D/Rvir. The HI covering fraction (k) within the virial radius, for a threshold of log10(N(HI)/cm^{-2}) = 14, is significantly lower for high-mass passive galaxies compared to their isolated, star-forming counterparts. The k-profile of isolated, star-forming galaxies suggests a characteristic size of the HI-rich CGM of ~ 1.5 Rvir, consistently across the stellar mass range. The mean HI mass in the outer CGM (0.3-1 Rvir ) increases with stellar mass, ranging from ~ 10^{5} to 10^{6.6} Msun. The b-parameters of the strongest HI components correlate and anti-correlate with specific star-formation rate (sSFR) and mass, respectively, with > 2 sigma significance. Broad Lya absorbers (BLAs) with b > 60 km s^{-1} are predominantly associated with high-mass galaxies, likely tracing the warm-hot phase of the CGM. The velocity centroids of HI components indicate that the absorbers at D < Rvir are predominantly consistent with being gravitationally bound to their associated galaxy, regardless of stellar mass. Finally, leveraging ~3000 galaxies with spectroscopic redshifts from the wide-field Magellan follow-up of six MUSEQuBES fields, we find that non-isolated galaxies exhibit an HI-rich environment that extends approximately three times further than for their isolated counterparts.