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GCN Circular 21804

LIGO/Virgo G298048: e-MERLIN upper limits on 5 GHz compact emission from SSS17a
2017-09-04T07:48:43Z (7 years ago)
Zsolt Paragi at Euro VLBI <>
Javier Moldon and Rob Beswick (JBO-Manchester University) for the EuroVLBI team

We monitored the field around the optical counterpart SSS17a (Coulter
et al., LVC 21529) with the e-MERLIN radio interferometer between
August 23 and 28, 2017. We conducted observations at C band centred at
5 GHz with a bandwidth of 512 MHz for 5 hours between 13:00 and 18:00
UTC in each consecutive day.

No significant detection above 5-sigma level is found in the runs with
individual rms noise levels between 31 and 39 microJy/beam. The upper
limits at 5-sigma level are 180, 160, 160, 190, 150, 150 microJy/beam
for days 23 to 28 August, respectively. The average half power beam
width of the images is 266 mas x 33 mas with a position angle of 0
degrees. An image produced combining the data from the six runs yields
an upper limit of 70 microJy/beam at the 5-sigma level.

Additional observations are planned with e-MERLIN to continue the
monitoring of the transient source.

e-MERLIN is a National Facility operated by the University of
Manchester at Jodrell Bank Observatory on behalf of STFC.

Zsolt Paragi
Head of User Support

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