TY - JOUR
T1 - ALMA deep field in SSA22
T2 - Blindly detected CO emitters and [C II ] emitter candidates
AU - Hayatsu, Natsuki H.
AU - Matsuda, Yuichi
AU - Umehata, Hideki
AU - Yoshida, Naoki
AU - Smail, Ian
AU - Swinbank, A. Mark
AU - Ivison, Rob
AU - Kohno, Kotaro
AU - Tamura, Yoichi
AU - Kubo, Mariko
AU - Iono, Daisuke
AU - Hatsukade, Bunyo
AU - Nakanishi, Kouichiro
AU - Kawabe, Ryohei
AU - Nagao, Tohru
AU - Inoue, Akio K.
AU - Takeuchi, Tsutomu T.
AU - Lee, Minju
AU - Ao, Yiping
AU - Fujimoto, Seiji
AU - Izumi, Takuma
AU - Yamaguchi, Yuki
AU - Ikarashi, Soh
AU - Yamada, Toru
N1 - Publisher Copyright:
© The Author 2017. Published by Oxford University Press on behalf of the Astronomical Society of Japan. All rights reserved. For Permissions, please email:.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - We report the identification of four millimeter line-emitting galaxies with the Atacama Large Milli/submillimeter Array (ALMA) in SSA22 Field (ADF22). We analyze the ALMA 1.1-mm survey data, with an effective survey area of 5 arcmin 2, frequency ranges of 253.1-256.8 and 269.1-272.8 GHz, angular resolution of 0.″7 and rms noise of 0.8 mJy beam -1 at 36 km s -1 velocity resolution. We detect four line-emitter candidates with significance levels above 6σ. We identify one of the four sources as a CO(9-8) emitter at z = 3.1 in a member of the proto-cluster known in this field. Another line emitter with an optical counterpart is likely a CO(4-3) emitter at z = 0.7. The other two sources without any millimeter continuum or optical/near-infrared counterpart are likely to be [C ii] emitter candidates at z = 6.0 and 6.5. The equivalent widths of the [C ii] candidates are consistent with those of confirmed high-redshift [C ii] emitters and candidates, and are a factor of 10 times larger than that of the CO(9-8) emitter detected in this search. The [C ii] luminosity of the candidates are 4-7 × 10 8 L ⊙. The star formation rates (SFRs) of these sources are estimated to be 10-20 M ⊙ yr -1 if we adopt an empirical [C ii] luminosity-SFR relation. One of them has a relatively low S/N ratio, but shows features characteristic of emission lines. Assuming that at least one of the two candidates is a [C ii] emitter, we derive a lower limit of [C ii]-based star formation rate density (SFRD) at z ∼ 6. The resulting value of >10 -2 M ⊙ yr -1 Mpc -3 is consistent with the dust-uncorrected UV-based SFRD. Future millimeter/submillimeter surveys can be used to detect a number of high-redshift line emitters, with which to study the star formation history in the early universe.
AB - We report the identification of four millimeter line-emitting galaxies with the Atacama Large Milli/submillimeter Array (ALMA) in SSA22 Field (ADF22). We analyze the ALMA 1.1-mm survey data, with an effective survey area of 5 arcmin 2, frequency ranges of 253.1-256.8 and 269.1-272.8 GHz, angular resolution of 0.″7 and rms noise of 0.8 mJy beam -1 at 36 km s -1 velocity resolution. We detect four line-emitter candidates with significance levels above 6σ. We identify one of the four sources as a CO(9-8) emitter at z = 3.1 in a member of the proto-cluster known in this field. Another line emitter with an optical counterpart is likely a CO(4-3) emitter at z = 0.7. The other two sources without any millimeter continuum or optical/near-infrared counterpart are likely to be [C ii] emitter candidates at z = 6.0 and 6.5. The equivalent widths of the [C ii] candidates are consistent with those of confirmed high-redshift [C ii] emitters and candidates, and are a factor of 10 times larger than that of the CO(9-8) emitter detected in this search. The [C ii] luminosity of the candidates are 4-7 × 10 8 L ⊙. The star formation rates (SFRs) of these sources are estimated to be 10-20 M ⊙ yr -1 if we adopt an empirical [C ii] luminosity-SFR relation. One of them has a relatively low S/N ratio, but shows features characteristic of emission lines. Assuming that at least one of the two candidates is a [C ii] emitter, we derive a lower limit of [C ii]-based star formation rate density (SFRD) at z ∼ 6. The resulting value of >10 -2 M ⊙ yr -1 Mpc -3 is consistent with the dust-uncorrected UV-based SFRD. Future millimeter/submillimeter surveys can be used to detect a number of high-redshift line emitters, with which to study the star formation history in the early universe.
KW - early universe
KW - galaxies: clusters: individual (SSA22)
KW - galaxies: formation
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U2 - 10.1093/pasj/psx018
DO - 10.1093/pasj/psx018
M3 - Article
AN - SCOPUS:85021394858
SN - 0004-6264
VL - 69
JO - Publications of the Astronomical Society of Japan
JF - Publications of the Astronomical Society of Japan
IS - 3
M1 - 45
ER -