Mid-Infrared Identification of Faint Submillimeter Sources

Abstract

Faint submillimeter sources detected with the Submillimeter Common-User Bolometer Array on the James Clerk Maxwell Telescope have faced an identification problem due to the telescope's broad beam profile. Here we propose a new method to identify such submillimeter sources with a mid-infrared image having a finer point spread function. The Infrared Space Observatory has provided a very deep 6.7 um image of the Hawaii Deep Field SSA13. All three faint 850 um sources in this field have their 6.7 um counterparts. They have been identified with interacting galaxy pairs in optical images. These pairs are also detected in the radio. Two of them are optically faint and very red (I>24, I-K>4), one of which has a hard X-ray detection with the Chandra satellite. As these observing properties are similar to those of local ultraluminous infrared galaxies, their photometric redshifts are derived based on submillimeter to mid-infrared flux ratios assuming a spectral energy distribution (SED) of Arp220. Other photometric redshifts are obtained via chi^2 minimization between the available photometry data and template SEDs. Both estimates are in the range z=1-2, in good agreement with a spectroscopic redshift and a millimetric one. The reconstructed Arp220 SEDs with these redshift estimates are consistent with all the photometry data except Chandra's hard X-ray detection. The sources would be a few times more luminous than Arp220. With an assumption that AGN contributions are negligible, it appears that extremely high star formation rates are occurring in galaxies at high redshifts with massive stellar contents already in place.

6 pages, 2 figures, ApJL (accepted), a version with color figures at http://www.ioa.s.u-tokyo.ac.jp/~ysato/pub/2/sato-c.ps.gz

References in corpus (11)

• Resolving the extragalactic hard X-ray background
• Mapping the Evolution of High Redshift Dusty Galaxies with Submillimeter Observations of a Radio-Selected Sample
• The Canada-UK Deep Submillimetre Survey: The Survey of the 14-hour field
• The Nature of the Hard X-ray Background Sources: Optical, Near-infrared, Submillimeter, and Radio Properties
• Galaxy number counts - V. Ultra-deep counts: The Herschel and Hubble Deep Fields
• Testing the connection between the X-ray and submillimetre source populations using Chandra
• X-ray Sources in the Hubble Deep Field Detected by Chandra
• Subaru Deep Survey I. Near-Infrared Observations
• Confusion errors in astrometry and counterpart association
• High spatial resolution observations of CUDSS14A: a SCUBA-selected Ultraluminous galaxy at high redshift
• The Identification of the Submillimeter Galaxy SMM J00266+1708

Cited by in corpus (6)

• Hubble Space Telescope images of submillimeter sources: large, irregular galaxies at high redshift
• Further multiwavelength observations of the SSA22 Ly_alpha emitting `blob'
• A deep 6.7um survey in the SSA13 field with ISO
• Sub-millimeter detections of Spitzer Space Telescope galaxy populations
• Present-day scaling relations of submm galaxies: origin of spheroidal sytems
• Faint 6.7um Galaxies and their Contributions to the Stellar Mass Density in the Universe