Title: Coma Cluster Ultra-Diffuse Galaxies Are Not Standard Radio Galaxies,
Abstract: Matching members in the Coma cluster catalogue of ultra-diffuse galaxies
(UDGs, Yagi et al. 2016) from SUBARU imaging with a very deep radio continuum
survey source catalogue of the cluster (Miller et al. 2009) using the Karl G.
Jansky Very Large Array (VLA) within a rectangular region of ~ 1.19 square
degrees centred on the cluster core reveals matches consistent with random. An
overlapping set of 470 UDGs and 696 VLA radio sources in this rectangular area
finds 33 matches within a separation of 25 arcsec; dividing the sample into
bins with separations bounded by 5 arcsec, 10 arcsec, 20 arcsec and 25 arcsec
finds 1, 4, 17 and 11 matches. An analytical model estimate, based on the
Poisson probability distribution, of the number of randomly expected matches
within these same separation bounds is 1.7, 4.9, 19.4 and 14.2, each
respectively consistent with the 95 percent Poisson confidence intervals of the
observed values. Dividing the data into five clustercentric annuli of 0.1
degree, and into the four separation bins, finds the same result. This random
match of UDGs with VLA sources implies that UDGs are not radio galaxies by the
standard definition. Those VLA sources having integrated flux > 1 mJy at 1.4
GHz in Miller et al. (2009) without SDSS galaxy matches are consistent with the
known surface density of background radio sources. We briefly explore the
possibility that some unresolved VLA sources near UDGs could be young, compact,
bright, supernova remnants of type Ia events, possibly in the intracluster
volume.