Dobie et al. present results from a search for the radio counterpart
to the possible neutron star–black hole merger GW190814 with ASKAP.
They carried out 10 epochs of observation spanning 2–655 days
post-merger at a frequency of 944 MHz.
They find one radio transient, ASKAP J005022.3−230349,
the light curve for which is shown above.
Source-finder measurements are denoted by solid circles, while open diamond
markers show forced photometry on images with no detection.
ASKAP J005022.3−230349 tripled in luminosity between epochs 5
and 6 before slowly declining. While the final epoch shows a slight
rise compared to the trend of the previous data points, this deviation
from the trend is consistent with the expected variability due to
scintillation along this line of sight.
They find that even the most extreme assumptions of a highly energetic jet
propagating into a dense circum-merger medium cannot reproduce the observed
steep rise. They conclude that this source is not a viable
counterpart to GW190814, but do consider it to be a real (but unrelated)
radio transient that occurred months after the merger.
The paper will be published in Monthly Notices of the Royal Astronomical Society.
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