The AzTEC/SMA Interferometric Imaging Survey of Submillimeter-Selected High-Redshift Galaxies

TL;DR

This survey uses high-resolution interferometric imaging to study high-redshift submillimeter galaxies, confirming their associations, analyzing their morphology, and revealing a population of extremely luminous, radio-dim galaxies at higher redshifts, impacting galaxy formation theories.

Contribution

The paper provides the first complete interferometric followup of an unbiased sample of millimeter-selected SMGs, revealing a high-redshift, radio-dim galaxy population.

Findings

Confirmed radio-submillimeter association in SMGs

Analyzed submillimeter galaxy morphology and physical scales

Identified a population of high-redshift, radio-dim, luminous SMGs

Abstract

We present results from a continuing interferometric survey of high-redshift submillimeter galaxies with the Submillimeter Array, including high-resolution (beam size ~2 arcsec) imaging of eight additional AzTEC 1.1mm selected sources in the COSMOS Field, for which we obtain six reliable (peak S/N>5 or peak S/N>4 with multiwavelength counterparts within the beam) and two moderate significance (peak S/N>4) detections. When combined with previous detections, this yields an unbiased sample of millimeter-selected SMGs with complete interferometric followup. With this sample in hand, we (1) empirically confirm the radio-submillimeter association, (2) examine the submillimeter morphology - including the nature of submillimeter galaxies with multiple radio counterparts and constraints on the physical scale of the far infrared - of the sample, and (3) find additional evidence for a population of extremely luminous, radio-dim submillimeter galaxies that peaks at higher redshift than previous, radio-selected samples. In particular, the presence of such a population of high-redshift sources has important consequences for models of galaxy formation - which struggle to account for such objects even under liberal assumptions - and dust production models given the limited time since the Big Bang.