GCN Circular 13298
Subject
GRB 120514A: GROND upper limits
Date
2012-05-14T16:45:37Z (13 years ago)
From
Vladimir Sudilovsky at MPE <vsudilov@mpe.mpg.de>
A. Nicuesa Guelbenzu (TLS Tautenburg), S. Schmidl (TLS Tautenburg), V.
Sudilovsky (MPE Garching), and J. Greiner (MPE Garching) report on
behalf of the GROND team:
We observed the field of GRB 120514A (Mangano et al., GCN #13289)
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120,
405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
Observation started at 03:39 UT, 2.4 h after the trigger and ended at
11:10 UT.
We detect two sources just outside of the enhanced 1.8" XRT error circle
at RA,DEC 18:52:00.1, -04:15:50.8 and 18:52:00.2, -04:15:46.8 with a
positional uncertainty of +/- 0.3". We note that neither source varies
in r' brightness relative to USNO field stars over a period of 2 hours.
Additionally, the southern source exhibits a thermal spectrum.
Therefore, neither of these two sources are likely associated with the GRB.
Based on exposures of 1480 seconds in g'r'i'z' and 1200 seconds in JHK,
we do not detect a source within the 1.8" XRT error circle of the X-ray
counterpart candidate (Evans et al., GCN #13292) to the following
3-sigma upper limits (AB system):
g' > 22.7,
r' > 23.0
i' > 23.0
z' > 23.0
J > 20.5
H > 19.6
K > 18.5
These magnitudes are calibrated against GROND zeropoints (g'r'i'z') and
2MASS (JHK) and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=1.7 mag in the
direction of the burst (Schlegel et al. 1998).