The Co-ordinated Radio and Infrared Survey for High-Mass Star Formation - II. Source Catalogue

TL;DR

The paper presents a high-resolution radio continuum survey of the Galactic plane, providing a new, reliable source catalogue with detailed data processing, noise analysis, and source detection methods, enhancing the study of high-mass star formation regions.

Contribution

It introduces a uniform, high-resolution radio source catalogue with improved imaging and detection reliability, based on advanced deconvolution and noise analysis techniques.

Findings

Detected 3,062 sources above 7-sigma threshold

Catalogue is over 90% complete at 3.9 mJy for unresolved sources

Survey optimised for emission scales up to 14 arcseconds

Abstract

The CORNISH project is the highest resolution radio continuum survey of the Galactic plane to date. It is the 5 GHz radio continuum part of a series of multi-wavelength surveys that focus on the northern GLIMPSE region (10 deg < l < 65 deg), observed by the Spitzer satellite in the mid-infrared. Observations with the Very Large Array in B and BnA configurations have yielded a 1.5" resolution Stokes I map with a root-mean-squared noise level better than 0.4 mJy/beam. Here we describe the data-processing methods and data characteristics, and present a new, uniform catalogue of compact radio-emission. This includes an implementation of automatic deconvolution that provides much more reliable imaging than standard CLEANing. A rigorous investigation of the noise characteristics and reliability of source detection has been carried out. We show that the survey is optimised to detect emission on size scales up to 14" and for unresolved sources the catalogue is more than 90 percent complete at a flux density of 3.9 mJy. We have detected 3,062 sources above a 7-sigma detection limit and present their ensemble properties. The catalogue is highly reliable away from regions containing poorly-sampled extended emission, which comprise less than two percent of the survey area. Imaging problems have been mitigated by down-weighting the shortest spacings and potential artefacts flagged via a rigorous manual inspection with reference to the Spitzer infrared data. We present images of the most common source types found: regions, planetary nebulae and radio-galaxies. The CORNISH data and catalogue are available online at http://cornish.leeds.ac.uk