Lyα Emitters at z = 5.7 in the Subaru Deep Field
Lyα Emitters at z = 5.7 in the Subaru Deep Field
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DOI：
10.1093/pasj/58.2.313
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发表时间：
2006-02
影响因子：
2.3
通讯作者：
K. Shimasaku;N. Kashikawa;M. Doi;C. Ly;M. Malkan;Y. Matsuda;M. Ouchi;T. Hayashino;M. Iye
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文献类型：
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作者：
K. Shimasaku;N. Kashikawa;M. Doi;C. Ly;M. Malkan;Y. Matsuda;M. Ouchi;T. Hayashino;M. Iye
PASJ:出版。阿斯特朗。Soc。日本，1 - ?？， c 2008。日本天文学会。斯巴鲁深场z = 5.7处Lyα发射体的岛佐和弘，1,2柏川信成，3,4土井守，5,2李春，6马肯，6松田雄一，7大内正美，8，柴野友树，9井野正典，3,4元原健太郎，5村山隆，长尾敏，3,11大田宽司，12冈村贞典，1,2佐佐木俊之，13盐谷康弘，10谷口义明10 arXiv: astroo -ph/0602614v1 2006年2月28日东京大学理学院天文学系Email (KS)：shimasaku@astron.s.u-tokyo.ac.jp东京大学理学院早期宇宙研究中心，东京113-0033东京三高国立天文台光学与红外天文学部，东京181-8588东京三高高等研究生院理学院天文学部，东京181-8588东京大学理学院天文研究所，三高181-0015加州大学洛杉矶分校天文学部，美国京都大学科学研究生院天文学系，京都606-8502空间望远镜科学研究所，巴尔的摩圣马丁大道3700号，马里兰州21218，美国东北大学科学研究生院中微子科学研究中心，仙台青叶市阿拉木市980-8578日本东北大学科学研究生院天文研究所，仙台青叶市阿拉木市980-8578日本国立天文台斯巴鲁望远镜，650 N. A 'ohoku Place, Hilo, HI 96720， USA（2005年10月26日接收；2006年2月27日接收）摘要研究了斯巴鲁深场z = 5.7处Lyα发射体（LAEs）的性质。利用窄带（NB816）数据，在连续725 arcmin 2区域内，将NB816 = 26.0 （AB）构建了89个LAE候选者的光度样品。利用斯巴鲁和凯克II型望远镜获得了39个满足lae光度选择标准的天体的光谱，其中28个为确认的lae， 1个为附近星系，8个为未分类天体。我们还获得了另外24个nb816过量物体的光谱，确定了另外6个LAEs。我们发现，当α = - 1.5（固定）时，用Schechter函数L - - - = 7.9 +3.0 erg s−1和φ - - - = 6.3−2.0 × 10−4 Mpc−3可以很好地再现由光度样品导出的Lyα光度函数。然后，我们测量了已确认的LAEs的静帧Lyα等效宽度（EWs），发现在28个满足光度选择标准的天体中，中位数为w0 = 233˚a。我们推断，在z = 5.7处，30% - 40%的LAEs超过了w0 = 240˚a。这些大ew天体可能无法用Salpeter IMF的普通恒星形成群来解释。我们还发现远紫外光度较弱的lae具有较大的EWs。最后，我们利用光度样品推导出LAEs远紫外亮度函数为M UV≃- 19.6，并与Lyman-break星系（LBGs）的远紫外亮度函数进行了比较。我们发现，在z ~ 6的LBGs中，高达约80%的w0≥100˚A，与低z的LBGs形成鲜明对比。关键词：星系；演化星系；高红移星系；光度函数
PASJ: Publ. Astron. Soc. Japan , 1–??, c 2008. Astronomical Society of Japan. Lyα Emitters at z = 5.7 in the Subaru Deep Field Kazuhiro Shimasaku, 1,2 Nobunari Kashikawa, 3,4 Mamoru Doi, 5,2 Chun Ly, 6 Matthew A.Malkan, 6 Yuichi Matsuda, 7 Masami Ouchi, 8,‡ Tomoki Hayashino, 9 Masanori Iye, 3,4 Kentaro Motohara, 5 Takashi Murayama, Tohru Nagao, 3,11 Kouji Ohta, 12 Sadanori Okamura, 1,2 Toshiyuki Sasaki, 13 Yasuhiro Shioya, 10 Yoshiaki Taniguchi 10 arXiv:astro-ph/0602614v1 28 Feb 2006 Department of Astronomy, School of Science, The University of Tokyo, Tokyo 113-0033 Email (KS): shimasaku@astron.s.u-tokyo.ac.jp Research Center for the Early Universe, School of Science, The University of Tokyo, Tokyo 113-0033 Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 Department of Astronomy, School of Science, Graduate University for Advanced Studies, Mitaka, Tokyo 181-8588 Institute of Astronomy, School of Science, The University of Tokyo, Mitaka 181-0015 Department of Astronomy, University of California at Los Angeles, Los Angeles, CA 90095-1547, USA Department of Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8502 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA Research Center for Neutrino Science, Graduate School of Science, Tohoku University, Aramaki, Aoba, Sendai 980-8578 Astronomical Institute, Graduate School of Science, Tohoku University, Aramaki, Aoba, Sendai 980-8578, Japan INAF / Osservatorio Astrofisico di Arcetri Largo E. Fermi 5, 50125 Firenze, Italy Kouji Ohta Department of Astronomy, Kyoto University, Kyoto 606-8502 Subaru Telescope, National Astronomical Observatory of Japan, 650 N. A’ohoku Place, Hilo, HI 96720, USA (Received 2005 October 26; accepted 2006 February 27) Abstract We present the properties of Lyα emitters (LAEs) at z = 5.7 in the Subaru Deep Field. A photometric sample of 89 LAE candidates is constructed from narrow-band (NB816) data down to N B816 = 26.0 (AB) in a continuous 725 arcmin 2 area. Spectra of 39 objects satisfying the photometric selection criteria for LAEs were obtained with Subaru and Keck II Telescopes, among which 28 were confirmed LAEs, one was a nearby galaxy, and eight were unclassified. We also obtained spectra of another 24 NB816-excess objects in the field, identifying six additional LAEs. We find that the Lyα luminosity function derived from the photometric sample is reproduced well by a Schechter function with L ⋆ = 7.9 +3.0 erg s −1 and φ ⋆ = 6.3 −2.0 × 10 −4 Mpc −3 for α = −1.5 (fixed) over the whole luminosity range of L ≃ 3 × 10 42 – 3 × 10 43 erg s −1 . We then measure rest-frame Lyα equivalent widths (EWs) for the confirmed LAEs, to find that the median among the 28 objects satisfying the photometric selection criteria is W i0 = 233 ˚ A. We infer that 30% – 40% of LAEs at z = 5.7 exceed W i0 = 240 ˚ A. These large-EW objects probably cannot be accounted for by ordinary star-forming populations with a Salpeter IMF. We also find that LAEs with fainter far-UV luminosities have larger EWs. Finally, we derive the far-UV luminosity function of LAEs down to M UV ≃ −19.6 using the photometric sample, and compare it with that of Lyman-break galaxies (LBGs). We find that as high as about 80% of LBGs at z ∼ 6 have W i0 ≥ 100 ˚ A, in sharp contrast to lower-z counterparts. Key words: galaxies: evolution — galaxies: high-redshift — galaxies: luminosity function, mass function — galaxies: photometry