GCN Circular 1166
Subject
GRB 011121
Event
Date
2001-11-30T16:55:44Z (25 years ago)
From
Jochen Greiner at Astrophys.Inst. Potsdam,Germany <jgreiner@aip.de>
J. Greiner (AIP Potsdam, Germany), S. Klose, A. Zeh (both TLS Tautenburg,
Germany), G. Lamer, R.D. Scholz, N. Lodieu (all AIP Potsdam, Germany),
E.v.d. Heuvel, P. Vreeswijk, L. Kaper (all Univ. Amsterdam, The Netherlands),
A.J. Castro-Tirado (IAA Granada, Spain), A. Fruchter (STScI, USA),
J. Hjorth (Copenhagen, Denmark), and E. Pian (Oss. Astr. Trieste, Italy),
V. Doublier, O. Hainaut, S. Hubrig, R. Johnson, A. Kaufer, M. Kuerster,
E. Pompej, (all ESO, Chile),
report for the large European GRB-Afterglow collaboration:
Observations of the afterglow of GRB 011121 (GCN #1147 - #1161)
have been performed at ESO (Chile) starting 8.4 hrs after the GRB,
and continuing over 4 days. In particular, K band imaging has been
obtained with SOFI at NTT (La Silla) and with ISAAC at Antu (Paranal)
at 0.4-0.9 arcsec seeing conditions. The best-seeing images (taken Nov. 24,
starting at 06:24 UT) resolve the afterglow and the surrounding emission to
hitherto unprecedented resolution. We do not see any diffuse emission.
Instead, besides the afterglow and the other "faint source" at 2 arcsec
distance reported earlier in GCN #1160 and #1163 (which we denote as
object "2"), we find two more sources (see the Figures at
http://www.aip.de/grb011121): one in between these two objects,
about 0.9 arcsec East of the afterglow (and denoted as "1" in the following),
and one about 1 arcsec south-east of the "faint source" (denoted "3").
The location and relative brightness of these objects 1 and 3 make
us believe that they are the cause for the earlier reports on "diffuse
emission" (see Figure 3). Thus, it is conceivable that object "2" is not
related to the GRB or its host. The source of the radio nebulosity (GCN #1156)
remains to be resolved.