%0 Generic %1 shibuya2017silverrush %A Shibuya, Takatoshi %A Ouchi, Masami %A Harikane, Yuichi %A Rauch, Michael %A Ono, Yoshiaki %A Mukae, Shiro %A Higuchi, Ryo %A Kojima, Takashi %A Yuma, Suraphong %A Lee, Chien-Hsiu %A Furusawa, Hisanori %A Konno, Akira %A Martin, Crystal L. %A Shimasaku, Kazuhiro %A Taniguchi, Yoshiaki %A Kobayashi, Masakazu A. R. %A Kajisawa, Masaru %A Nagao, Tohru %A Goto, Tomotsugu %A Kashikawa, Nobunari %A Komiyama, Yutaka %A Kusakabe, Haruka %A Momose, Rieko %A Nakajima, Kimihiko %A Tanaka, Masayuki %A Wang, Shiang-Yu %D 2017 %K Lya UV emission high-z nebulae %T SILVERRUSH. III. Deep Optical and Near-Infrared Spectroscopy for Lya and UV-Nebular Lines of Bright Lya Emitters at z=6-7 %U http://arxiv.org/abs/1705.00733 %X We present Lya and UV-nebular emission line properties of bright Lya emitters (LAEs) at z=6-7 with a luminosity of log L_Lya/erg s-1 = 43-44 identified in the 21-deg2 area of the SILVERRUSH early sample developed with the Subaru Hyper Suprime-Cam (HSC) survey data. Our optical spectroscopy newly confirm 21 bright LAEs with clear Lya emission, and contribute to make a spectroscopic sample of 97 LAEs at z=6-7 in SILVERRUSH. From the spectroscopic sample, we select 7 remarkable LAEs as bright as Himiko and CR7 objects, and perform deep Keck/MOSFIRE and Subaru/nuMOIRCS near-infrared spectroscopy reaching the 3sigma-flux limit of ~ 2x10^-18 erg s-1 for the UV-nebular emission lines of He II1640, C IV1548,1550, and O III1661,1666. Except for one tentative detection of C IV, we find no strong UV-nebular lines down to the flux limit, placing the upper limits of the rest-frame equivalent widths (EW_0) of ~2-4 A for He II, C IV, and O III lines. Here we also investigate the VLT/X-SHOOTER spectrum of CR7 whose 6 sigma detection of He II is claimed by Sobral et al. Although two individuals and the ESO-archive service carefully re-analyze the X-SHOOTER data that are used in the study of Sobral et al., no He II signal of CR7 is detected, supportive of weak UV-nebular lines of the bright LAEs even for CR7. Spectral properties of these bright LAEs are thus clearly different from those of faint dropouts at z~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 line EW_0 and UV-continuum luminosity, which are similar to those found at z~2-3.

@misc{shibuya2017silverrush, abstract = {We present Lya and UV-nebular emission line properties of bright Lya emitters (LAEs) at z=6-7 with a luminosity of log L_Lya/[erg s-1] = 43-44 identified in the 21-deg2 area of the SILVERRUSH early sample developed with the Subaru Hyper Suprime-Cam (HSC) survey data. Our optical spectroscopy newly confirm 21 bright LAEs with clear Lya emission, and contribute to make a spectroscopic sample of 97 LAEs at z=6-7 in SILVERRUSH. From the spectroscopic sample, we select 7 remarkable LAEs as bright as Himiko and CR7 objects, and perform deep Keck/MOSFIRE and Subaru/nuMOIRCS near-infrared spectroscopy reaching the 3sigma-flux limit of ~ 2x10^{-18} erg s-1 for the UV-nebular emission lines of He II1640, C IV1548,1550, and O III]1661,1666. Except for one tentative detection of C IV, we find no strong UV-nebular lines down to the flux limit, placing the upper limits of the rest-frame equivalent widths (EW_0) of ~2-4 A for He II, C IV, and O III] lines. Here we also investigate the VLT/X-SHOOTER spectrum of CR7 whose 6 sigma detection of He II is claimed by Sobral et al. Although two individuals and the ESO-archive service carefully re-analyze the X-SHOOTER data that are used in the study of Sobral et al., no He II signal of CR7 is detected, supportive of weak UV-nebular lines of the bright LAEs even for CR7. Spectral properties of these bright LAEs are thus clearly different from those of faint dropouts at z~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 line EW_0 and UV-continuum luminosity, which are similar to those found at z~2-3.}, added-at = {2017-05-03T13:00:01.000+0200}, author = {Shibuya, Takatoshi and Ouchi, Masami and Harikane, Yuichi and Rauch, Michael and Ono, Yoshiaki and Mukae, Shiro and Higuchi, Ryo and Kojima, Takashi and Yuma, Suraphong and Lee, Chien-Hsiu and Furusawa, Hisanori and Konno, Akira and Martin, Crystal L. and Shimasaku, Kazuhiro and Taniguchi, Yoshiaki and Kobayashi, Masakazu A. R. and Kajisawa, Masaru and Nagao, Tohru and Goto, Tomotsugu and Kashikawa, Nobunari and Komiyama, Yutaka and Kusakabe, Haruka and Momose, Rieko and Nakajima, Kimihiko and Tanaka, Masayuki and Wang, Shiang-Yu}, biburl = {https://www.bibsonomy.org/bibtex/248c5b7726dfd80554e240fcf383f8e24/miki}, description = {[1705.00733] SILVERRUSH. III. Deep Optical and Near-Infrared Spectroscopy for Lya and UV-Nebular Lines of Bright Lya Emitters at z=6-7}, interhash = {e1f09315a141913a2373f8742966a2ea}, intrahash = {48c5b7726dfd80554e240fcf383f8e24}, keywords = {Lya UV emission high-z nebulae}, note = {cite arxiv:1705.00733Comment: 24 pages, 11 figures, submitted to PASJ special issue}, timestamp = {2017-05-03T13:00:01.000+0200}, title = {SILVERRUSH. III. Deep Optical and Near-Infrared Spectroscopy for Lya and UV-Nebular Lines of Bright Lya Emitters at z=6-7}, url = {http://arxiv.org/abs/1705.00733}, year = 2017 }