TITLE:   GCN CIRCULAR
NUMBER:  17839
SUBJECT: GRB 150518A: AMI 15 GHz detection of possible radio counterpart
DATE:    15/05/21 14:46:27 GMT
FROM:    Gemma Anderson at U of Oxford  <Gemma.Anderson@physics.ox.ac.uk>

G. E. Anderson, K. Mooley, R. P. Fender, T. D. Staley (University of Oxford),
A. J. van der Horst (George Washington University), A. Rowlinson (CASS)

We observed the XRT position of GRB 150518A discovered by MAXI
(Sbarufatti et al., GCN  17827, Kawamuro et al., GCN 17825) at 15 GHz
with the Arcminute Microkelvin Imager (AMI-LA) starting on
2015 May 20.962 to 21.128 UT, corresponding to 2.1 days post-burst
(Golenetskii et al., GCN 17837). On this date we detected a radio source
coincident with the position of the optical counterpart (Xu et al., GCN 17829)
with a preliminary flux of 0.19 +/- 0.04 mJy. There are no catalogued radio
sources at this position.

An earlier observation was conducted on 2015 May 19.975 to 20.142 UT,
corresponding to 1.1 days post-burst, yielding a 3 sigma flux upper limit
of 0.13 mJy.

Further AMI monitoring is planned. We thank the AMI staff for scheduling these observations.