The MAVERIC Survey: Radio catalogs and source counts from deep Very
  Large Array imaging of 25 Galactic globular clusters
  The MAVERIC survey is the first deep radio continuum imaging survey of Milky
Way globular clusters, with a central goal of finding and classifying accreting
compact binaries, including stellar-mass black holes. Here we present radio
source catalogs for 25 clusters with ultra-deep Karl G. Jansky Very Large Array
observations. The median observing time was 10 hr per cluster, resulting in
typical rms sensitivities of 2.3 and 2.1 uJy per beam at central frequencies of
5.0 and 7.2 GHz, respectively. We detect nearly 1300 sources in our survey at 5
sigma, and while many of these are likely to be background sources, we also
find strong evidence for an excess of radio sources in some clusters. The radio
spectral index distribution of sources in the cluster cores differs from the
background, and shows a bimodal distribution. We tentatively classify the
steep-spectrum sources (those much brighter at 5.0 GHz) as millisecond pulsars
and the flat-spectrum sources as compact or other kinds of binaries. These
provisional classifications will be solidified with the future addition of
X-ray and optical data. The outer regions of our images represent a deep,
relatively wide field (~ 0.4/sq. deg) and high resolution C band background
survey, and we present source counts calculated for this area. We also release
radio continuum images for these 25 clusters to the community.
