MUSEQuBES: Characterizing the circumgalactic medium of redshift ≈3.3 Lyα emitters
MUSEQuBES: Characterizing the circumgalactic medium of redshift ≈3.3 Lyα emitters
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MUSEQuBES：表征红移 ≈3.3 Lyα 发射体的环河介质
DOI：
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发表时间：
2021
影响因子：
4.8
通讯作者：
J. Zabl
中科院分区：
文献类型：
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作者：
S. Muzahid;J. Schaye;S. Cantalupo;R. Marino;N. Bouché;S. Johnson;M. Maseda;M. Wendt;L. Wisotzki;J. Zabl
利用VLT/MUSE在以8个明亮背景类星体为中心的场中探测到的96 z≈3.3 LAEs样本，首次表征了Lyα发射体（LAEs）的环星系介质。lae具有较低的Lyα光度（~ 1042 erg s−1）和恒星形成速率（SFRs） ~ 1 M⊙yr−1，这对于主序星系来说对应的恒星质量仅为~ 108.6 M⊙。LAEs与类星体视线之间的中间横向距离为165正kpc （pkpc）。我们叠加了高分辨率的类星体光谱，并在LAEs附近测量了显著的过量H i和C iv吸收，达到500 km s−1，至少≈250 pkpc（对应于≈7维里半径）。在距离星系> 30 km s−1处，中间的H i和C iv光学深度增加了一个数量级。在约1/3的“基团”LAEs附近，吸收明显更强，我们将其归因于它们嵌入的大规模结构。我们没有检测到H i或C iv吸收与横向距离（在≈50−250 pkpc范围内）、红移或Lyα发射线的性质（光度、半最大值时的全宽度或等效宽度）有任何强烈的依赖性。然而，对于H i，而不是C iv，在< 100 km s−1处从LAE的吸收随SFR的增加而增加。这表明被更多H i包围的LAEs具有更高的SFRs。
We present the first characterization of the circumgalactic medium of Lyα emitters (LAEs), using a sample of 96 z ≈ 3.3 LAEs detected with the VLT/MUSE in fields centered on 8 bright background quasars. The LAEs have low Lyα luminosities (∼1042 erg s−1) and star formation rates (SFRs) ∼1 M⊙ yr−1, which for main sequence galaxies corresponds to stellar masses of only ∼108.6 M⊙. The median transverse distance between the LAEs and the quasar sightlines is 165 proper kpc (pkpc). We stacked the high-resolution quasar spectra and measured significant excess H i and C iv absorption near the LAEs out to 500 km s−1 and at least ≈250 pkpc (corresponding to ≈7 virial radii). At ≲ 30 km s−1 from the galaxies the median H i and C iv optical depths are enhanced by an order of magnitude. The absorption is significantly stronger around the ≈1/3 of our LAEs that are part of ‘groups’, which we attribute to the large-scale structures in which they are embedded. We do not detect any strong dependence of either the H i or C iv absorption on transverse distance (over the range ≈50 − 250 pkpc), redshift, or the properties of the Lyα emission line (luminosity, full width at half maximum, or equivalent width). However, for H i, but not C iv, the absorption at ≲ 100 km s−1 from the LAE does increase with the SFR. This suggests that LAEs surrounded by more H i tend to have higher SFRs.