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arXiv · 1607.02331

SXDF-ALMA 2 Arcmin^2 Deep Survey: Resolving and Characterizing the Infrared Extragalactic Background Light Down to 0.5 mJy

Yuki Yamaguchi·Yoichi Tamura·Kotaro Kohno·Itziar Aretxaga·James S. Dunlop·Bunyo Hatsukade·David Hughes·Soh Ikarashi·Shun Ishii·Rob J. Ivison·Takuma Izumi·Ryohei Kawabe·Tadayuki Kodama·Minju Lee·Ryu Makiya·Yuichi Matsuda·Kouichiro Nakanishi·Kouji Ohta·Wiphu Rujopakarn·Ken-ichi Tadaki·Hideki Umehata·Wei-Hao Wang·Grant W. Wilson·Kiyoto Yabe·Min S. Yun
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Abstract

We present a multi-wavelength analysis of five submillimeter sources (S_1.1mm = 0.54-2.02 mJy) that were detected during our 1.1-mm-deep continuum survey in the SXDF-UDS-CANDELS field (2 arcmin^2, 1sigma = 0.055 mJy beam^-1) using the Atacama Large Millimeter/submillimeter Array (ALMA). The two brightest sources correspond to a known single-dish (AzTEC) selected bright submillimeter galaxy (SMG), whereas the remaining three are faint SMGs newly uncovered by ALMA. If we exclude the two brightest sources, the contribution of the ALMA-detected faint SMGs to the infrared extragalactic background light is estimated to be ~ 4.1^{+5.4}_{-3.0} Jy deg^{-2}, which corresponds to ~ 16^{+22}_{-12}% of the infrared extragalactic background light. This suggests that their contribution to the infrared extragalactic background light is as large as that of bright SMGs. We identified multi-wavelength counterparts of the five ALMA sources. One of the sources (SXDF-ALMA3) is extremely faint in the optical to near-infrared region despite its infrared luminosity (L_IR ~ 1e12 L_sun or SFR ~ 100 M_sun yr^{-1}). By fitting the spectral energy distributions (SEDs) at the optical-to-near-infrared wavelengths of the remaining four ALMA sources, we obtained the photometric redshifts (z_photo) and stellar masses (M_*): z_photo ~ 1.3-2.5, M_* ~ (3.5-9.5)e10 M_sun. We also derived their star formation rates (SFRs) and specific SFRs (sSFRs) as ~ 30-200 M_sun yr^{-1} and ~ 0.8-2 Gyr^{-1}, respectively. These values imply that they are main-sequence star-forming galaxies.

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Yuki Yamaguchi, Yoichi Tamura, Kotaro Kohno, Itziar Aretxaga, James S. Dunlop, Bunyo Hatsukade, David Hughes, Soh Ikarashi, Shun Ishii, Rob J. Ivison, Takuma Izumi, Ryohei Kawabe, Tadayuki Kodama, Minju Lee, Ryu Makiya, Yuichi Matsuda, Kouichiro Nakanishi, Kouji Ohta, Wiphu Rujopakarn, Ken-ichi Tadaki, Hideki Umehata, Wei-Hao Wang, Grant W. Wilson, Kiyoto Yabe, Min S. Yun. 2016-07-08. SXDF-ALMA 2 Arcmin^2 Deep Survey: Resolving and Characterizing the Infrared Extragalactic Background Light Down to 0.5 mJy. https://doi.org/10.1093/pasj%2Fpsw073

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