[vsnet-grb-info 4843] GRB 070612A: Second Epoch WSRT Radio Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6576
SUBJECT: GRB 070612A: Second Epoch WSRT Radio Observations
DATE:    07/06/24 10:19:49 GMT
FROM:    Alexander van der Horst at U of Amsterdam  <avdhorst at science.uva.nl>

A.J. van der Horst, R.A.M.J. Wijers, K. Wiersema (University of Amsterdam),
and E. Rol (University of Leicester) report on behalf of a larger
collaboration:

"We reobserved the position of the GRB 070612A afterglow (GCN 6509) at
4.9 GHz with the Westerbork Synthesis Radio Telescope at June 20 7.91 UT
to 19.76 UT, i.e. 8.22 - 8.71 days after the burst.
At the position of the optical counterpart (GCN 6515, GCN 6525) and the
tentative radio counterpart (GCN 6549), we measure a formal flux of
72 +/- 27 microJy, i.e. a possible radio source at 2.7 sigma significance.
In a combined image of the two epochs of WSRT observations, at June 15 and
June 20, the average formal flux is 53 +/- 19 microJy, a 2.8 sigma
detection. Therefore, we cannot state with certainty whether the radio
afterglow (or the possible host galaxy) of GRB 070612A is detected.

We would like to thank the WSRT staff for scheduling and obtaining these
observations."