(Proposal ID) S10B-086

(PI) Kohno, Kotaro

(Proposal Title)
Rest-Frame Optical Spectroscopy of AzTEC-ASTE SMGs in SXDF

(Abstract)
We propose a near-infrared spectroscopic survey of the NIR counterparts 
candidates of submillimeter galaxies (SMGs) uncovered by AzTEC-on-ASTE lambda 
1100 mu m deep survey of Subaru XMM-Newton Deep Field (SXDF) using FMOS on 
SUBARU. The surveyed area and depth are ~ 1000 arcmin^2 and 0.5 - 1 mJy 
(1 sigma), which are sufficient to uncover ULIRGs at z > 1.5, and we have 
detected ~120 robust SMGs within the surveyed area. This is the largest sample 
of SMGs in SXDF to date. The field size and the number of the sources with the 
AzTEC-ASTE are just suited for the FMOS. Thanks to its unique capability of 
FMOS, it is expected to double the number of SMGs with the rest-frame optical 
spectra, which are currently limited to just 20-30 objects, if this project is 
successfully conducted. With the largest SMG sample with the rest-frame optical spectra, we will be able to address the fundamental properties of SMGs, i.e., 
(1) their redshift distributions, (2) dust extinctions (if we detect both 
H alpha and H beta), (3) star formation rates (from H alpha and/or [OII]), 
and (4) constraints on the heating source (if we detect [OII] and H beta), i.e., AGN fraction in SMGs, or metalicity. This must also be a unique project from 
Japan in the ALMA era by a close collaboration between SUBARU and ASTE.