ATCA observations of
GRB990627
These results have been obtained as part of project C651 by D.A. Frail,
S.R. Kulkarni, the ATCA Alert group and the BeppoSAX GRB team.
Permission to quote results should be obtained from Dale Frail
(dfrail@aoc.nrao.edu).
Observations on 99:06:28 - Day 1
-
We obtained an 11 hour integration centered on June 28.67 at 4.8 GHz
(including 3 h at 4.9 GHz) and an 8 hour integration centered on
June 28.76 at 8.6 GHz (375M array + 6km antenna).
Within the 3' WFC error circle there are four 6 cm sources and two 3
cm sources above 5 sigma, named Source 1 to 4 below. (Fluxes corrected
for primary beam attenuation). Source 1 and 2 appear to be extended.
- Source 1: RA 01:48:29.65, DEC -77:06:53.3 (J2000),
Fluxdensity 5.58 mJy(6cm), 2.39 mJy(3cm).
- Source 2: RA 01:49:02.61, DEC -77:05:17.8 (J2000),
Fluxdensity 0.47 mJy(6cm).
- Source 3: RA 01:48:33.42, DEC -77:04:12.0 (J2000),
Fluxdensity 0.33 mJy(6cm), 0.29 mJy(3cm).
- Source 4: RA 01:48:28.94, DEC -77:02:54.7 (J2000),
Fluxdensity 0.44 mJy(6cm).
- Image:
8.6 GHz image of the GRB WFC
error circle, 56 uJy noise
- Image:
4.8 GHz image of the GRB WFC
error circle, 47 uJy noise
- Image:
4.8 GHz image with the GRB WFC
and NFI error circles, 37 uJy noise
Observations on 99:07:02 - Day 5
-
We obtained a 10 hour integration centered on July 2.83 at 4.8 GHz
and 8.6 GHz (750D array + 6km antenna).
The fluxes of the source seen in the previous observation are given
below. No signficant changes are detected. In particular source 3,
within the 1' NFI error circle, does not seem to have varied
significantly at either frequency. No other sources have appeared
above 5 sigma.
(Fluxes corrected for primary beam attenuation).
- Source 1: RA 01:48:29.55, DEC -77:06:53.6 (J2000),
Fluxdensity 5.58 mJy(6cm), 2.85 mJy(3cm).
- Source 2: RA 01:49:01.49, DEC -77:05:22.5 (J2000),
Fluxdensity 0.61 mJy(6cm).
- Source 3: RA 01:48:32.97, DEC -77:04:12.9 (J2000),
Fluxdensity 0.32 mJy(6cm), 0.28 mJy(3cm).
- Source 4: RA 01:48:28.98, DEC -77:02:53.1 (J2000),
Fluxdensity 0.36 mJy(6cm).
- Image:
8.6 GHz image with the GRB WFC
and NFI error circles, 40 uJy noise
- Image:
4.8 GHz image with the GRB WFC
and NFI error circles, 36 uJy noise
Observations on 99:07:09 - Day 12
-
We obtained an 8 hour integration centered on July 9.87 at 4.8 GHz
and 8.6 GHz (750D array + 6km antenna). We do not find evidence for a
GRB radio afterglow.
(Fluxes corrected for primary beam attenuation).
- Source 1: RA 01:48:29.58, DEC -77:06:53.6 (J2000),
Fluxdensity 5.76 mJy(6cm), 2.53 mJy(3cm).
- Source 2: RA 01:49:01.49, DEC -77:05:22.5 (J2000),
Fluxdensity 0.46 mJy(6cm).
- Source 3: RA 01:48:32.97, DEC -77:04:12.9 (J2000),
Fluxdensity 0.38 mJy(6cm), 0.25 mJy(3cm).
- Source 4: RA 01:48:28.98, DEC -77:02:53.1 (J2000),
Fluxdensity 0.39 mJy(6cm).
- Image:
8.6 GHz image with the GRB WFC
and NFI error circles, 42 uJy noise
- Image:
4.8 GHz image with the GRB WFC
and NFI error circles, 42 uJy noise
Last changed on: 13-jul-1999
Mark.Wieringa@atnf.csiro.au