GCN Circular 35507
Subject
GRB 231215A: radio detection with the VLA
Date
2024-01-09T13:31:45Z (4 months ago)
From
Stefano Giarratana at University of Bologna <s.giarratana@ira.inaf.it>
Via
email
S. Giarratana (University of Bologna, INAF-IRA), M. Giroletti
(INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.),
N. Omodei (Stanford Univ.)
At 03:57:39 UT on 2023 December 20 (T_mid = 4.8 days post-burst) the
Karl G. Jansky VLA started observing the field of GRB 231215A
(D'Avanzo et al., GCN 35343) at a central frequency of 6 and 10 GHz.
The standard J0542+4951 was used as bandpass and flux density
calibrator, while J0102+5824 was used as complex gain calibrator.
From a preliminary analysis, an unresolved radio source (Rhodes et al.,
GCN 35397) is clearly detected at both frequencies at a position:
RA: 00:38:57.53 +- 0.05
Dec: +57:38:50.7 +- 0.6
The surface brightness peak is 61 uJy/beam and 128 uJy/beam at 6
and 10 GHz, respectively. The r.m.s. noise level of the images is
7 uJy/beam at both 6 and 10 GHz.
The synthesized beams are 13.1 x 9.9 arcsec (PA: -66deg) at 6 GHz
and 7.7 x 6.0 arcsec (PA: -59deg) at 10 GHz.
We would like to thank the staff of the VLA for approving, executing,
and processing the observations.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc.
These observations were carried out as part of project SF161095,
approved in the framework of the Fermi - NRAO joint program agreement.