The QUaD Galactic Plane Survey. II. A Compact Source Catalog

Abstract

We present a catalog of compact sources derived from the QUaD Galactic Plane Survey. The survey covers ~800 deg2 of the inner galaxy (|b| < 4°) in Stokes I, Q, and U parameters at 100 and 150 GHz, with angular resolutions of 5 and 3.5 arcmin, respectively. Five hundred and twenty-six unique sources are identified in I, of which 239 are spatially matched between frequency bands, with 53 (234) detected at 100 (150) GHz alone; 170 sources are identified as ultracompact H ii regions. Approximating the distribution of total intensity source fluxes as a power law, we find a slope of γS, 100 = −1.8 ± 0.4 at 100 GHz and γS, 150 = −2.2 ± 0.4 at 150 GHz. Similarly, the power-law index of the source two-point angular correlation function is γθ, 100 = −1.21 ± 0.04 and γθ, 150 = −1.25 ± 0.04. The total intensity spectral index distribution peaks at αI ~ 0.25, indicating that dust emission is not the only source of radiation produced by these objects between 100 and 150 GHz; free–free radiation is likely significant in the 100 GHz band. Four sources are detected in polarized intensity P, of which three have matching counterparts in I. Three of the polarized sources lie close to the Galactic center, Sagittarius A*, Sagittarius B2, and the Galactic Radio Arc, while the fourth is RCW 49, a bright H ii region. An extended polarized source, undetected by the source extraction algorithm on account of its ~0fdg5 size, is identified visually, and is an isolated example of large-scale polarized emission oriented distinctly from the bulk Galactic dust polarization.