Extragalactic millimeter-wave point source catalog, number counts and statistics from 771 square degrees of the SPT-SZ Survey

TL;DR

This paper presents a catalog of extragalactic millimeter-wave sources from the SPT-SZ survey, classifies sources into two populations, and compares observed counts with galaxy models, highlighting discrepancies and implications for future models.

Contribution

First comprehensive millimeter-wave point source catalog from the SPT-SZ survey with classification, cross-matching, and comparison to galaxy models.

Findings

Detected 1545 sources above 4.5 sigma significance.

Identified two populations: synchrotron and dusty star-forming galaxies.

Observed counts do not match existing galaxy population models.

Abstract

We present a point source catalog from 771 square degrees of the South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey at 95, 150, and 220 GHz. We detect 1545 sources above 4.5 sigma significance in at least one band. Based on their relative brightness between survey bands, we classify the sources into two populations, one dominated by synchrotron emission from active galactic nuclei, and one dominated by thermal emission from dust-enshrouded star-forming galaxies. We find 1238 synchrotron and 307 dusty sources. We cross-match all sources against external catalogs and find 189 unidentified synchrotron sources and 189 unidentified dusty sources. The dusty sources without counterparts are good candidates for high-redshift, strongly lensed submillimeter galaxies. We derive number counts for each population from 1 Jy down to roughly 9, 5, and 11 mJy at 95, 150, and 220 GHz. We compare these counts with galaxy population models and find that none of the models we consider for either population provide a good fit to the measured counts in all three bands. The disparities imply that these measurements will be an important input to the next generation of millimeter-wave extragalactic source population models.