The stellar mass, star formation rate and dark matter halo properties of LAEs at z ~ 2
The stellar mass, star formation rate and dark matter halo properties of LAEs at z ~ 2
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LAE 在 z ~ 2 处的恒星质量、恒星形成率和暗物质晕特性
DOI：
10.1093/pasj/psx148
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发表时间：
2018
影响因子：
2.3
通讯作者：
K. et al. (10 authors in total)
中科院分区：
文献类型：
--
作者：
Kusakabe;H.;Shimasaku;K. et al. (10 authors in total)
我们从光谱能量分布拟合和聚类分析中分别获得了z ~ 2个Lyα发射体（LAEs）的平均恒星居群特性和暗物质晕质量，并在四个单独的场中使用了总计为1 deg2的1250个物体（）。LAEs的平均恒星质量为10.2±1.8 × 108M⊙，恒星形成速率为3.4±0.4M⊙yr−1，位于恒星形成主序（MS）到低恒星质量的外推。它们的有效暗物质晕质量估计具有有效偏差，低于先前基于三倍小的调查区域的研究获得的z ~ 2 LAEs(1.8±0.3)，概率为96%。然而，如果考虑到宇宙方差，偏差值的差异是可以解释的。如果这样的低晕质量意味着低Higas质量，这个结果似乎与高Lyα逃逸分数的观测结果一致。由于低晕质量和持续的恒星形成，我们的lae具有相对较高的恒星与晕质量比（SHMR）和较高的重子转化为恒星的效率。扩展的Press-Schechter形式预测，atz= 0的lae通常嵌入与大麦哲伦星云（LMC）质量相似的光晕中；如果它们的恒星形成速率在z ~ 2之后受到很大程度的抑制，就像之前一些研究对LMC本身所报道的那样，它们也将具有与LMC相似的shmr。
We present average stellar population properties and dark matter halo masses ofz∼ 2 Lyα emitters (LAEs) from spectral energy distribution fitting and clustering analysis, respectively, using ≃ 1250 objects () in four separate fields of ≃ 1 deg2in total. With an average stellar mass of 10.2 ± 1.8 × 108M⊙and star formation rate of 3.4 ± 0.4M⊙yr−1, the LAEs lie on an extrapolation of the star-formation main sequence (MS) to low stellar mass. Their effective dark matter halo mass is estimated to bewith an effective bias of, which is lower than that ofz∼ 2 LAEs (1.8 ± 0.3) obtained by a previous study based on a three times smaller survey area, with a probability of 96%. However, the difference in the bias values can be explained if cosmic variance is taken into account. If such a low halo mass implies a low Higas mass, this result appears to be consistent with the observations of a high Lyα escape fraction. With the low halo masses and ongoing star formation, our LAEs have a relatively high stellar-to-halo mass ratio (SHMR) and a high efficiency of converting baryons into stars. The extended Press–Schechter formalism predicts that atz= 0 our LAEs are typically embedded in halos with masses similar to that of the Large Magellanic Cloud (LMC); they will also have similarSHMRs to the LMC, if their star formation rates are largely suppressed afterz∼ 2 as some previous studies have reported for the LMC itself.