GRB 001018
GCN Circular 853
Subject
IPN TRIANGULATION OF GRB001018
Date
2000-10-19T18:46:05Z (25 years ago)
From
Kevin Hurley at UCBerkeley/SSL <khurley@sunspot.ssl.berkeley.edu>
K. Hurley, on behalf of the Ulysses GRB team,
T. Cline, on behalf of the Konus-Wind and NEAR GRB teams,
and E. Mazets, and S. Golenetskii, on behalf of the KONUS-WIND GRB team, report:
Ulysses, NEAR, and KONUS-WIND observed this GRB at 61114 seconds.
As observed by Ulysses, it had a duration of approximately 31.
seconds, a 25-100 keV fluence of approximately 1.2E-05 erg/cm2,
and a peak flux of approximately 5.0E-01 erg/cm2 s over .50 seconds
We have triangulated it to a preliminary, 3 sigma error
whose approximate area is 15. sq. arcmin. and whose
coordinates are:
RA(2000) DEC(2000)
ERROR BOX CENTER: 13 h 14 m 10.27 s 11 o 48 ' 31.75 "
ERROR BOX CORNER 1: 13 h 14 m 13.68 s 11 o 49 ' 31.43 "
ERROR BOX CORNER 2: 13 h 13 m 50.40 s 11 o 51 ' 29.08 "
ERROR BOX CORNER 3: 13 h 14 m 30.12 s 11 o 45 ' 34.18 "
ERROR BOX CORNER 4: 13 h 14 m 6.85 s 11 o 47 ' 32.06 "
This error box may be improved
GCN Circular 854
Subject
CORRECTION TO PEAK FLUX OF GRB001018
Date
2000-10-19T21:26:29Z (25 years ago)
From
Kevin Hurley at UCBerkeley/SSL <khurley@sunspot.ssl.berkeley.edu>
In GCN #853, and in the socket message IPN #8, the peak flux
should have read 5.0E-6 erg/cm^2 s.
Kevin Hurley
GCN Circular 856
Subject
GRB001018, Gamma Ray Observations
Date
2000-10-21T01:34:07Z (25 years ago)
From
Srikanta Sinha at ISRO/ISAC <sinha@isac.ernet.in>
S. Sinha, P. Sreekumar, K. Kasturirangan, on behalf of SROSS C-2 (INDIAN
GRB EXPERIMENT) team report:
SROSS C-2 observed this burst at 61116.784 s UT (this time may contain
small systematic errors). As observed by SROSS C-2, it had a duration
(T90) of 1.63 +- 0.05 secs, a 20-1024 keV fluence (not corrected for the
sec(theta) factor since we donot know the direction) equal to 1.15 X 10 -5
ergs cm-2. The peak flux (256 ms) in 20-100 keV band is equal to 20.09
photons cm-2 sec-1 and the peak flux (256 ms) in 100-1024 keV band is
equal to 12.15 photons cm-2 sec-1. The Hardness Ratio (at the peak of the
burst) is equal to 0.32 +- 0.05. Our Hardness Ratio is defined as
[counts(100-1024 keV)/counts(20-100 keV)]. For 21 SROSS C-2 GRBs that are
common with BATSE we find a mean Hardness Ratio of 0.97 +- 0.08 and the
standard deviation of the hardness distribution is equal to 0.37.
This message is citable.
-Srikanta Sinha, on behalf of the SROSS C-2 (INDIAN GRB EXPERIMENT TEAM)
at the Technical Physics Division, ISRO Satellite Center, Bangalore-560
017, INDIA.
GCN Circular 857
Subject
GRB 001018, Possible Radio Afterglow
Date
2000-10-21T06:03:17Z (25 years ago)
From
Greg Taylor at NRAO <gtaylor@aoc.nrao.edu>
G. B. Taylor (NRAO) reports on behalf of a larger collaboration:
"We imaged the IPN error box of GRB001018 (GCN #853) with the VLA at
8.46 GHz, starting on Oct. 19.88 UT. A second observation was
obtained starting on Oct. 20.76 UT. One unresolved radio source (size
< 0.25 arcsec) is detected within the IPN error box at (J2000) R.A.=
13 14 12.385, Dec. =11 48 57.90 with an error of approximately 50 mas
in each coordinate. The VLA flux density at 8.46 GHz was 258 +/- 65
microJy on Oct 19.88, and 405 +/- 50 microJy on Oct 20.76. No source
is detected in the NRAO VLA Sky Survey (NVSS; Condon et al. 1998, AJ,
115, 1693) above their flux limit of 1 mJy at 1.4 GHz. Based on its
compact and possibly variable nature we suggest that the source VLA
J1314+1148 could be the radio afterglow from G001018. Further
observations with the VLA are planned."
This message may be cited.
GCN Circular 915
Subject
Optical observations of GRB 001018 with JCAM
Date
2001-01-18T20:00:39Z (24 years ago)
From
Josh Bloom at CIT <jsb@astro.caltech.edu>
Optical observations of GRB 001018 with JCAM
J. S. Bloom, A. Diercks, S. R. Kulkarni, F. A. Harrison, (Caltech), B. B.
Behr (U. Texas), J. C. Clemens (UNC) report on behalf of the larger
GRB-NRAO-CARA GRB collaboration:
"On 18 December 2000 UT, J. Bloom and D. Reichart observed the field of
GRB 001018 (Hurley et al., GCN #853) near the transient radio position
reported by Taylor et al. (GCN #857) on the Palomar 200-inch telescope
during a commissioning run of the Jacobs Camera (JCAM), a dual-CCD imager
designed primarily for rapid follow-up of GRB afterglow. The plate scale
of JCAM is 0.38 arcsec/pixel and the field-of-view is 3.2 x 3.2 arcmin^2.
We observed the GRB field simultaneously in R- and B-band for a total of
2700s. An astrometric plate solution was obtained using 10 (11) ties stars
common to both the USNO-A2.0 catalogue and the R- (B-) band summed image.
The total absolute astrometric uncertainty in the R-band plate solution
was 0.32", 0.27" in RA and Dec. Unfortunately, the seeing (2.8 arcsec
FWHM in R-band) was very poor at Palomar on 18 December and there was
significant extinction due to cirrus. At the position of Taylor's radio
transient there were no detected objects to R~22.7 mag (5-sigma); the
photometric zeropoint was estimated using the USNO stars in the field."
The R and B finding chart images of the may be obtained at:
http://www.astro.caltech.edu/~jsb/GRB/grb001018/
For further information on JCAM, please see:
http://www.astro.caltech.edu/~jsb/Jcam
This message may be cited.
GCN Circular 918
Subject
Optical Observations of GRB 001018 at Keck
Date
2001-01-21T23:33:36Z (24 years ago)
From
Josh Bloom at CIT <jsb@astro.caltech.edu>
Optical Observations of GRB 001018 at Keck
J. S. Bloom, S. G. Djorgovski, F. A. Harrison, P. Mao (Caltech), and
D. Stern (JPL) report on behalf of the larger Caltech-NRAO-CARA GRB
Collaboration:
"We observed the field of GRB 001018 (Hurley et al., GCN #853) with the
Keck Telescopes on the nights of 29 December 2000 UT and 1 January 2001 UT
with LRIS (Oke et al. 1995) and ESI (Sheinis et al. 2000), respectively.
About 1 arcsec from the position of the radio transient reported by Taylor
et al. (GCN #857), we find a faint compact source, likely an unresolved
galaxy.
An astrometric plate solution was obtained using 16 USNO A2.0 stars in
common with a 20s R-band exposure with LRIS. The total r.m.s errors on the
resulting tie to the ICRS were 0.31", 0.27" (ra,dec), including the
systematic uncertainties in the USNO A2.0 catalogue described by Deutsch
1998. Including the uncertainties in the radio position and the nearby
galaxy position, the centroid of the galaxy is 0.46" +/- 0.32" E, 0.89"
+/- 0.27" N of Taylor's radio transient. Given the proximity to the radio
transient, this galaxy may be related to the radio transient.
We obtained photometric zeropoints using the Landolt standard star fields
of PG1047+003 (R-band) and SA 104 (I-band). For the galaxy, we find that
I=24.03 +/- 0.10 mag (1 Jan 01 UT) and R=24.60 +/- 0.09 mag. This
detection is consistent with the upper limit placed by Bloom et al. (GCN
#915). For comparison, we find for stars A (ra=13:14:09.9, dec=+11:48:56,
J2000) and B (ra=13:14:09.4, dec=+11:48:23, J2000) that I(A) = 18.42 +/-
0.03 mag, R(A) = 18.54 +/- 0.03 mag, I(B) = 18.82 +/- 0.03 mag, and R(B) =
19.91 +/- 0.03 mag."
This message may be cited.