The SARAO MeerKAT Galactic Plane Survey compact source catalogue

TL;DR

This paper presents a comprehensive catalogue of over half a million compact radio sources from the MeerKAT Galactic Plane Survey, revealing many previously unknown sources and providing new insights into Galactic radio emission.

Contribution

The paper introduces a new, large-scale catalogue of compact sources from MeerKAT data, including source identification, characterization, and initial scientific analysis.

Findings

Detection of 510,599 compact sources, mostly previously unknown.

Identification of 213 radio-quiet WISE HII region candidates.

High sensitivity and uv-coverage demonstrated through comparison with other surveys.

Abstract

We present a catalogue of compact sources detected in the SARAO MeerKAT 1.3 GHz Galactic Plane Survey (SMGPS). We extract 510599 compact sources, with areas less than five 8" beams, from the survey maps covering the regions $252\deg< l < 358^\deg$ and $2\deg < l < 61\deg$ at $|b| \leq 1.5^\deg$, which have an angular resolution of 8" and a sensitivity of $\sim$ 10-30 $\mu$Jy beam$^{-1}$. In this paper, we describe the source identification and characterisation methods, present the quality assurance of the catalogue, explore the nature of the catalogue sources, and present initial science highlights. We limit our catalogue to sources with a signal-to-noise ratio $\geq 5$, as the catalogue is $\sim$90 per cent complete, and has a false positive rate of less than 1 per cent at this threshold. The bulk of the catalogue sources are previously unknown to the literature, with the majority of unknown sources at sub-mJy levels. Initial science highlights from the catalogue include the detection of 213 radio quiet WISE HII region candidates, previously undetected in radio continuum studies. We show images that compare the SMGPS compact sources to CORNISH ultracompact HII regions, thus highlighting the sensitivity and unprecedented uv-coverage of the SMGPS, and the potential synergy of the SMGPS with other surveys.