A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). I. An Ultradeep SCUBA-2 Survey of the GOODS-N* † ‡ §

Abstract

In this first paper in the SUPER GOODS series on powerfully star-forming galaxies in the two GOODS fields, we present a deep SCUBA-2 survey of the GOODS-N at both 850 and 450 μm (central rms noise of 0.28 mJy and 2.6 mJy, respectively). In the central region, the 850 μm observations cover the GOODS-N to near the confusion limit of ∼1.65 mJy, while over a wider 450 arcmin2 region—well complemented by Herschel far-infrared imaging—they have a median limit of 3.5 mJy. We present catalogs of 186 850 μm and 31 450 μm selected sources. We use interferometric observations from the Submillimeter Array (SMA) and the Karl G. Jansky Very Large Array (VLA) to obtain precise positions for 114 SCUBA-2 sources (28 from the SMA, all of which are also VLA sources). We present new spectroscopic redshifts and include all existing spectroscopic or photometric redshifts. We also compare redshifts estimated using the 20 cm/850 μm and the 250 cm/850 μm flux ratios. We show that the redshift distribution increases with increasing flux, and we parameterize the dependence. We compute the star formation history and the star formation rate (SFR) density distribution functions in various redshift intervals, finding that they reach a peak at before dropping to higher redshifts. We show that the number density per unit volume of galaxies measured from the SCUBA-2 sample does not change much relative to that of lower SFR galaxies from UV selected samples over , suggesting that, apart from changes in the normalization, the shape in the number density as a function of SFR is invariant over this redshift interval.

A Machine-learning Method for Identifying Multiwavelength Counterparts of Submillimeter Galaxies: Training and Testing Using AS2UDS and ALESS

“…Traditionally, the likely counterparts for single-dish submillimeter sources were identified by using indirect tracers of the far-infrared/submillimeter emission, such as the radio, 24 μm, or mid-infrared properties (e.g., Ivison et al 1998;Smail et al 2002;Pope et al 2006;Ivison et al 2007;Barger et al 2012;Michałowski et al 2012;Cowie et al 2017). These properties roughly track the far-infrared luminosity of galaxies, and they have two additional advantages: that observations in these bands are typically at significantly higher angular resolution than the submillimeter, and that the surface densities of sources in these wavebands are relatively low, so that the rate of chance associations is also low.…”

The Hawaii SCUBA-2 Lensing Cluster Survey: Radio-detected Submillimeter Galaxies in the HST Frontier Fields

“…850 m (mJy), which is more than a factor of two smaller than the conversion (143) found in Cowie et al (2017). However, the median redshifts of the two samples are z = 1.24 (this work) and z = 2.28 (Cowie et al).…”

“…Barger et al (2014) and Cowie et al (2017) have both measured the mean conversion between observed 850 μm flux density and IR SFR from their samples, with a multiplicative range over the individual values of two in each direction about the mean. Here we perform the same exercise, comparing our observed 850 μm flux densities and IR SFRs for the 10 sources that have IR SFR measurements in Figure 6.…”

“…Submillimeter/millimeter interferometry is the only method to find out whether there are other radio-faint counterparts to these SCUBA-2 sources. Cowie et al (2017) inspected the positional uncertainty of the SCUBA-2 850 μm sources detected in the Chandra Deep Field-North (CDF-N). They found that the offsets between the SCUBA-2 positions and the SMA positions or the 1.4 GHz counterparts are all <4 5 for 102 sources with 850 μm flux densities above 2 mJy.…”

“…Because SMGs are dusty and have high extinction, many of them are not detected in UV/optical surveys (e.g., Barger et al 2012;Simpson et al 2014). To understand how the most massive galaxies formed and how the star-formation rate (SFR) density evolves with cosmic time, it is crucial to study these SMGs since they contribute a significant fraction (>10%) of the star formation at high redshifts (e.g., Barger et al 2000Barger et al , 2012Barger et al , 2014Chapman et al 2005;Wang et al 2006;Serjeant et al 2008;Wardlow et al 2011;Casey et al 2013;Cowie et al 2017).…”