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 - Funding Information:
This work was supported by the ALMA Japan Research Grant of National Astronomical Observatory of Japan (NAOJ) Chile Observatory, NAOJ-ALMA-0071 and NAOJ-ALMA-0160. NHH was supported by the grant of NAOJ Visiting Fellow Program supported by the Research Coordination Committee, National Astronomical Observatory of Japan (NAOJ) and by funding from Foundation for Promotion of Astronomy. IRS acknowledges support from STFC (ST/L00075X/1), the ERC Advanced Grant DUSTYGAL (321334) and a Royal Society Wolfson Research Merit Award.
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
VL - 69
JO - Publication of the Astronomical Society of Japan
JF - Publication of the Astronomical Society of Japan
SN - 0004-6264
IS - 3
M1 - 45
ER -