GCN Circular 19233
Subject
GRB 160325A: GROND Upper Limits
Date
2016-03-26T01:22:14Z (9 years ago)
From
Corentin Delvaux at MPE <delvaux@mpe.mpg.de>
C. Delvaux (MPE Garching), D. A. Kann (TLS Tautenburg), F. Knust, and J.
Greiner (both MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 160325A (Swift trigger 680436; Sonbas et
al., GCN #19222, Fermi GBM detection, Roberts, GCN #19924, Fermi LAT
detection, Axelsson et al., GCN #19227) simultaneously in g'r'i'z'JHK
with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG
telescope at ESO La Silla Observatory (Chile).
Observations started at 23:29 UT on 25/03/2016, 16.5 hrs after the GRB
trigger. They were performed at an average seeing of 1.7" and at an
average airmass of 2.3.
We do not detect the source reported by Fugazza et Melandri (GCN #19223)
down to the following magnitudes (in AB system):
g > 22.4 mag,
r > 22.5 mag,
i > 22.3 mag,
z > 22.4 mag,
J > 20.3 mag,
H > 19.8 mag, and
K > 18.5 mag.
Given upper limits are calibrated against GROND zeropoints as well as
2MASS field stars and are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of E_(B-V)=0.1 mag in
the direction of the burst (Schlafly & Finkbeiner 2011).