The MAVERIC survey: a catalogue of radio sources in southern globular clusters from the Australia Telescope Compact Array. Issue 3 (14th April 2022)

• Record Type: Journal Article
• Authors: Tudor, Vlad; Miller-Jones, James C A; Strader, Jay; Bahramian, Arash; Shishkovsky, Laura; Plotkin, Richard M; Chomiuk, Laura; Heinke, Craig O; Maccarone, Thomas J; Sivakoff, Gregory R; Tremou, Evangelia; Anderson, Gemma E; Russell, Thomas D; Tzioumis, Anastasios K
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 513:Issue 3(2022)
• Page Start: 3818
• Page End: 3835
• Publication Date: 2022-04-14
• Subjects: globular clusters: general -- pulsars: general -- radio continuum: general -- surveys -- X-rays: binaries; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac1034
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Radio continuum observations offer a new window on compact objects in globular clusters compared to typical X-ray or optical studies. As part of the MAVERIC survey, we have used the Australia Telescope Compact Array to carry out a deep (median central noise level ≈4 $\mu$ Jy beam -1 ) radio continuum survey of 26 southern globular clusters at central frequencies of 5.5 and 9.0 GHz. This paper presents a catalogue of 1285 radio continuum sources in the fields of these 26 clusters. Considering the surface density of background sources, we find significant evidence for a population of radio sources in seven of the 26 clusters, and also identify at least 11 previously known compact objects (six pulsars and five X-ray binaries). While the overall density of radio continuum sources with 7.25-GHz flux densities ≳ 20 $\mu$ Jy in typical globular clusters is relatively low, the survey has already led to the discovery of several exciting compact binaries, including a candidate ultracompact black hole X-ray binary in 47 Tuc. Many of the unclassified radio sources near the centres of the clusters are likely to be true cluster sources, and multiwavelength follow-up will be necessary to classify these objects and better understand the demographics of accreting compact binaries in globular clusters.