SILVERRUSH. III. Deep optical and near-infrared spectroscopy for Lyα and UV-nebular lines of bright Lyα emitters at z=6-7
SILVERRUSH. III. Deep optical and near-infrared spectroscopy for Lyα and UV-nebular lines of bright Lyα emitters at z=6-7
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SILVERRUSH。III.Lyα 和 z=6-7 处明亮 Lyα 发射体的紫外星云线的深光学和近红外光谱。
DOI：
10.1093/pasj/psx107
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发表时间：
2017
影响因子：
2.3
通讯作者：
Kaji
中科院分区：
文献类型：
--
作者：
Shibuya Takatoshi;Ouchi Masami;Harikane Yuichi;Rauch Michael;Ono Yoshiaki;Mukae Shiro;Higuchi Ryo;Kojima Takashi;Yuma Suraphong;Lee Chien-Hsiu;Furusawa Hisanori;Konno Akira;Martin Crystal L;Shimasaku Kazuhiro;Taniguchi Yoshiaki;Kobayashi Masakazu A R;Kaji
我们介绍了在斯巴鲁Hyper Suprime-Cam巡天数据开发的SILVERRUSH早期样品的21 deg 2区域中发现的亮度为logLLyα/[erg s−1] = 43-44的明亮Lyα发射体（LAEs）的Lyα和紫外星云发射线特性。我们的光谱学新确认了21个明亮的LAEs，具有清晰的Lyα发射，并有助于在SILVERRUSH中制备96个LAEs at = 6-7的光谱样品。从光谱样品中，我们选择了7个与Himiko和CR 7天体一样明亮的LAE，并对Heiiλ1640，Civλλ 1548，1550和Oiii]λλ 1661，1666的紫外星云发射线进行了深Keck/MOSFIRE和Subaru/nuMOIRCS近红外光谱测量，达到了3 σ通量极限为102 × 10− 18 erg s− 1。除了一个Civ的试探性检测，我们没有发现强的UV星云线下降到通量极限，放置的休息框架等效宽度（EW 0）的上限为2.2 -4毫米的Civ，Heii，和Oiii]线。我们还研究了索布拉尔等人提出的CR 7的VLT/X-SHOOTER谱。尽管两个人和ESO档案服务仔细地重新分析了索布拉尔等人研究中使用的X-SHOOTER数据，没有探测到CR 7的HeiI信号，这支持了即使对于CR 7，明亮LAEs的弱UV星云线。因此，这些明亮的LAEs的光谱特性明显不同于那些在各种研究中显示的具有强紫外星云线的暗淡的dropouts atz 107。比较这些明亮的LAEs和暗淡的dropouts，我们发现UV-星云线EW 0和UV-连续发光度之间的反相关，这与atz 2.3发现的相似。
We present Lyα and UV-nebular emission line properties of bright Lyα emitters (LAEs) atz= 6–7 with a luminosity of logLLyα/[erg s−1] = 43–44 identified in the 21 deg2area of the SILVERRUSH early sample developed with the Subaru Hyper Suprime-Cam survey data. Our optical spectroscopy newly confirms 21 bright LAEs with clear Lyα emission, and contributes to making a spectroscopic sample of 96 LAEs atz= 6–7 in SILVERRUSH. From the spectroscopic sample, we select seven remarkable LAEs as bright as Himiko and CR7 objects, and perform deep Keck/MOSFIRE and Subaru/nuMOIRCS near-infrared spectroscopy reaching the 3 σ flux limit of ∼2 × 10−18erg s−1for the UV-nebular emission lines of Heiiλ1640, Civλλ1548,1550, and Oiii]λλ1661,1666. Except for one tentative detection of Civ, we find no strong UV-nebular lines down to the flux limit, placing the upper limits of the rest-frame equivalent widths (EW0) of ∼2–4 Å for Civ, Heii, and Oiii] lines. We also investigate the VLT/X-SHOOTER spectrum of CR7 whose 6 σ detection of Heiiis claimed by Sobral et al. Although two individuals and the ESO archive service carefully reanalyzed the X-SHOOTER data that are used in the study of Sobral et al., no Heiisignal of CR7 is detected, supportive of weak UV-nebular lines of the bright LAEs even for CR7. The spectral properties of these bright LAEs are thus clearly different from those of faint dropouts atz∼ 7 that have strong UV-nebular lines shown in the various studies. Comparing these bright LAEs and the faint dropouts, we find anti-correlations between the UV-nebular lineEW0and the UV-continuum luminosity, which are similar to those found atz∼ 2–3.