研究成果・発表論文

A Strong Ly\ensuremathα Emitter at z = 6.33 in the Subaru Deep Field Selected as an i'-Dropout

Nagao, T.,   Taniguchi, Y.,   Kashikawa, N.,   Kodaira, K.,   Kaifu, N.,   Ando, H.,   Karoji, H.,   Ajiki, M.,   Akiyama, M.,   Aoki, K.,   Doi, M.,   Fujita, S.~S.,   Furusawa, H.,   Hayashino, T.,   Iwamuro, F.,   Iye, M.,   Kobayashi, N.,   Kodama, T.,   Komiyama, Y.,   Matsuda, Y.,   Miyazaki, S.,   Mizumoto, Y.,   Morokuma, T.,   Motohara, K.,   Murayama, T.,   Nariai, K.,   Ohta, K.,   Okamura, S.,   Ouchi, M.,   Sasaki, T.,   Sato, Y.,   Sekiguchi, K.,   Shimasaku, K.,   Shioya, Y.,   Tamura, H.,   Tanaka, I.,   Umemura, M.,   Yamada, T.,   Yasuda, N.,   & Yoshida, M.


要旨
We report on the discovery of a star-forming galaxy at z=6.33 in the Subaru Deep Field. This object is selected as a candidate of an i$^′$-dropout high-redshift galaxy around z=6 because of its red i$^′$-z$^′$ color in our deep optical imaging survey in the Subaru Deep Field. Our follow-up optical spectroscopy reveals that this object is a strong Ly\ensuremathα emitter with only very faint ultraviolet continuum. The rest- frame equivalent width of the detected Ly\ensuremathα emission is as much as 130 ̊A. Thus the light detected in our z$^′$ image is largely attributed to the Ly\ensuremathα emission, i.e., \i̊sebox-0.5ex~40% of the z$^′$-band flux is the strong Ly\ensuremathα emission, giving a very red i$^′$-z$^′$ color. This is consistent with the photometric property of this object because the narrowband data obtained with the NB921 filter show a significant depression, z$^′$-NB921=-0.54 mag. By using the photometric data, we show that some other objects among the 48 i$^′$-dropout high- redshift galaxy candidates found in the Subaru Deep Field also show a significant NB921 depression. We briefly discuss the nature of these NB921-depressed objects.

Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.




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