GRB 081203B
GCN Circular 8602
Subject
GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
Date
2008-12-03T21:38:46Z (17 years ago)
From
Antonio Copete at Harvard U <acopete@head.cfa.harvard.edu>
A. Copete, J. Grindlay (Harvard)
S. Barthelmy, C. Markwardt, N. Gehrels, J. Cummings (NASA/GSFC), D.
Palmer (LANL)
We hereby correct the naming of the burst first reported by Copete et
al (GCN 8600), which is unrelated to GRB 081203A (GCNs 8595, 8596,
8598, 8599 and 8601). Following the standard naming convention for
same-day bursts to take into account the order of announcement, this
burst must rather be named GRB 081203B. This name should be used in
all follow-up circulars referring to this burst.
GCN Circular 8605
Subject
GRB 081203B: Swift-XRT candidate afterglow.
Date
2008-12-03T23:13:37Z (17 years ago)
From
Boris Sbarufatti at INAF-IASF-Pa <sbarufatti@ifc.inaf.it>
B. Sbarufatti, V. La Parola, V. Mangano (INAF-IASF Pa) report on
behalf of the Swift-XRT team:
Swift began observing the field of the Swift BAT Slew Survey (BATSS)
GRB 081203B (Copete et al., GCN Circ. 8600, 8602) 16.7 ks after the
trigger. Using 1419 s of XRT Photon Counting mode data we detect a
single uncatalogued source inside the BAT error circle. Using the XRT
data and 2 UVOT images, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field
sources to the USNO-B1 catalogue): RA, Dec =
228.7993, 44.4284 which is equivalent to:
RA (J2000): 15 15 11.83
Dec (J2000): +44 25 42.3
with an uncertainty of 1.8 arcsec (radius, 90% confidence). The
source lies 27 arcsec from the BAT centroid and has a count rate of
~5.5e-1 counts/s during this observation.
It is not possible to determine whether this source is fading given
the current statistics. Further observations are ongoing to clarify
the nature of this source.
This circular is an official product of the Swift-XRT team.
GCN Circular 8606
Subject
Swift/UVOT detection of GRB081203B
Date
2008-12-04T00:37:27Z (17 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P. Schady (MSSL-UCL), F.E. Marshall (NASA/GSFC) and B. Sbarufatti
(INAF-IASF Pa) report on behalf of the Swift/UVOT team:
The Swift/UVOT began white band observations of the field of the Swift
BAT Slew Survey (BATSS) GRB 081203B 4.6 hrs after the BAT trigger
(Copete et al., GCN Circ. 8600, 8602). An uncatalogued, fading source
is clearly detected at
RA(J2000.0) = 15:15:11.67 (228.79863 deg)
DEC(J2000.0) = +44:25:42.9 (44.42859 deg)
with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence),
consistent with the UVOT-enhanced XRT position (Sbarufatti et al., GCN
Circ. 8605).
The magnitudes of the first and last UVOT white band observations are
reported below:
Filter T_mid (s) Exp (s) Magnitude
white 16746 154 18.29 +/- 0.04
white 22270 441 18.70 +/- 0.03
indicating a decay rate of alpha~1.0. The above magnitudes are not
corrected for the Galactic extinction corresponding to a reddening of
E_{B-V} = 0.02 mag (Schlegel et al., 1998, ApJS, 500, 525). The
photometry is on the UVOT flight system described in Poole et al.
(2008, MNRAS, 383,627).
GCN Circular 8607
Subject
GRB 081203B: SDSS upper limits at the position of the optical afterglow
Date
2008-12-04T03:32:18Z (17 years ago)
From
Edo Berger at Harvard <eberger@cfa.harvard.edu>
E. Berger (Harvard) reports:
"Inspection of SDSS images at the position of the optical afterglow of BAT
Slew Survey GRB 081203B (GCNs #8600,8606) reveals no coincident source to
the following 3-sigma limits:
u > 22.3 mag
g > 23.5 mag
r > 23.4 mag
i > 22.6 mag
z > 21.2 mag."
GCN Circular 8608
Subject
GRB 081203B: optical observations
Date
2008-12-04T04:13:20Z (17 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
M. Andreev, A. Sergeev, (Terskol Branch of Institute of Astronomy), Ju.
Babina (CrAO) A. Pozanenko (IKI) on behalf of larger GRB follow up
collaboration report:
We observed the field of GRB 081203B detected by SWIFT in a slew mode
(Copeteet al, GCN 8600) with the Z-600 telescope of Mt. Terskol
observatory. A set of R-band exposures was taken starting Dec. 04 (UT)
01:44. In a combined image of 10x90 s taken at mid time Dec. 04 (UT)
01:53:45 we detect afterglow (Schady et al, GCN 8606) in coordinate
(J2000) 15 15 11.66 +44 25 42.7. A preliminary photometry of the
afterglow at Dec. 04 (UT) 01:53:45 is R=19.8. The photometry is based on
USNO-A2.0 field stars.
The combine image can be found at
http://grb.rssi.ru/GRB081203B/grb081203B_Z600_01_53_45.jpg
GCN Circular 8610
Subject
Konus-Wind observation of GRB 081203B
Date
2008-12-04T12:34:28Z (17 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team report:
The long Swift-BATSS GRB 081203B (Copete et al., GCN 8600, 8602)
triggered Konus-Wind at T0=49890.368 s UT (13:51:30.368).
The burst light curve shows a multipeaked structure with a total
duration of ~80 s.
As observed by Konus-Wind the burst
had a fluence of 5.56(-0.23, +0.24)x10^-5 erg/cm2,
and a 256-ms peak flux measured from T0+10.032 s
of 2.43(-0.40, +0.41)x10^-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).
The time-integrated spectrum of the burst
(from T0 to T0+64.000 s) can be fitted (in the 20 keV-2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.165(-0.054, +0.057),
and Ep = 255(-19, +22) keV (chi2 = 77.8/61 dof).
Fitting by GRB (Band) model yields the same alpha and Ep,
and only an upper limit on the high energy
photon index: beta < -2.59 (chi2 = 77.7/60 dof).
All the quoted errors are at the 90% confidence level.
The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB081203_T49890/
[GCN OPS NOTE(04dec08): Per author's request, the authors
were added.]
GCN Circular 8612
Subject
Swift-XRT observations of GRB 081203B
Date
2008-12-04T16:44:11Z (17 years ago)
From
Boris Sbarufatti at INAF-IASF-Pa <sbarufatti@ifc.inaf.it>
B. Sbarufatti, V. La Parola, V. Mangano (INAF IASF-Pa) report on
behalf of the Swift-XRT team.
We report on Swift-XRT observations of GRB 081203B (Copete et al. GCN
Circ. 8600,8602). We analyzed 3.2 ks of Photon Counting mode data for
this burst, covering times from T+17 ks to T+ 47 ks. The source
reported in Sbarufatti et al. (GCN Circ. 8605) and confirmed as the
afterglow by Schady et al. (GCN Circ. 8606) is fading following a
power-law decay with index alpha=-1.4 (+0.2/-0.1).
The spectrum for the first data sequence, corresponding to a 1.96 ks
exposure and covering times from T+17 ks to T+23 ks can be fit by a
power-law with photon index 2.1+/-0.2, with an absorbing column of
(7.4+/-0.2)E20 cm**-2, in excess with respect to the galactic value
of 1.94E20 cm**-2 (Kalberla et al. 2005). The observed (unabsorbed)
flux is 1.7 (2.2)E-11 erg cm**-2 s**-1. The count-rate-to-flux
conversion factor is (4.3+/-0.1)E-11.
All quoted errors are at 90% confidence level.
This circular is an official product of the Swift-XRT team.
GCN Circular 8625
Subject
Radio detection of GRB 081203B with the VLA
Date
2008-12-05T21:12:08Z (17 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward
optically bright GRB 081203B (GCN 8600) at a frequency of 8.46 GHz
on 2008 Dec 05.70 UT. We detect a radio afterglow at the optical
afterglow position quoted by Andreev et al (GCN 8608). The peak radio
flux at this position is 160 +/- 41 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 8626
Subject
GRB081203B: optical observations
Date
2008-12-05T21:53:05Z (17 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
M. Andreev, A. Sergeev, (Terskol Branch of Institute of Astronomy), Ju.
Babina (CrAO) A. Pozanenko (IKI) on behalf of larger GRB follow up
collaboration report:
We are continuing observation (Andreev et al, GCN 8608) of the GRB081203B
(Copeteet et al, GCN 8600) with the Z-600 telescope of Mt. Terskol
observatory. A set of R-band exposures was taken between Dec.05 (UT)
02:33-03:19. In a combined image of 30x90 s at mid time Dec. 05 (UT) 02:56
we still detect afterglow of the GRB081203B (Schady et al, GCN 8606). A
photometry of the afterglow is 20.9 +/- 0.3. The photometry is based on
USNO-A2.0 star 1275_08617401 (RA 15 15 10.21 Dec: +44 26 01.4) assuming
R=17.1.
GCN Circular 8631
Subject
GRB 081203B: Gemini observations
Date
2008-12-07T12:10:52Z (17 years ago)
From
Daniel Perley at U.C. Berkeley <dperley@astro.berkeley.edu>
D. A. Perley and J. S. Bloom (UC Berkeley) report:
We triggered Gemini-N (GMOS) observations of BATSS GRB 081203B (Copete
et al., GCN 8600, 8602) starting at 15:04 UT 2008-12-06 through very
high airmass but under good conditions. In our acquisition image we
identify a source at the position of the optical afterglow (Schady et
al., GCN 8606). Photometry, calibrated to SDSS, is:
r = 21.90 +/- 0.06 (t = 3.05 days)
Two spectroscopic integrations of 1200s each were acquired using the
R150 grating. Preliminary inspection of the frames reveals no obvious
line features between 5200-9000 A. Further analysis is continuing.
GCN Circular 8637
Subject
GRB 081203B: Additional Gemini imaging
Date
2008-12-08T05:07:27Z (17 years ago)
From
Daniel Perley at U.C. Berkeley <dperley@astro.berkeley.edu>
D. A. Perley (UC Berkeley) reports on behalf of a larger collaboration:
During morning twilight on 2008-12-07 UT (starting at 15:40) we
undertook additional imaging of the optical transient associated with
GRB 081203B, using GMOS on Gemini-North. We report the following
magnitudes:
g = 22.67 +/- 0.11 (t = 4.076 day)
r = 22.41 +/- 0.10 (t = 4.079 day)
i = 22.16 +/- 0.20 (t = 4.082 day)
Assuming a burst time of 13:52:02 UT (GCN 8600).
The SED is well-fit by a power-law with beta = 1.0 +/- 0.3. The
power-law index of the light curve compared with our r-band measurement
the previous night (GCN 8631) is alpha = 1.6 +/- 0.3. Both values are
consistent with typical late-time GRB afterglow behavior.
We thank the Gemini staff for conducting these observations, which were
carried out under program GN-2008B-Q-6.
GCN Circular 8638
Subject
GRB 081203B: Suzaku WAM observation of the prompt emission
Date
2008-12-08T08:18:54Z (17 years ago)
From
Masanori Ohno at ISAS/JAXA <ohno@astro.isas.jaxa.jp>
Y.Terada, M. Tashiro, Y. Urata, A. Endo, K. Onda,
N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.),
S. Sugita, K. Yamaoka (Aoyama Gakuin U.),
M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA),
Y.E. Nakagawa, T. Tamagawa (RIKEN),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo),
T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.),
E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono, H.Hayashi,
(Univ. of Miyazaki),S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:
The long GRB 081203B (Swift/BAT Slew Survey, Copete et al., GCN Circ. 8600,
8602) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers
an energy range of 50 keV - 5 MeV at 2008-12-03 13:51:31.94713598 UT (=T0).
The observed light curve shows a multi-peaked structure starting at T0-0.5s,
ending at T0+64s with a duration (T90) of about 45 seconds. The fluence in
100 - 1000 keV was 2.9 x 10^-5 erg/cm^2. The 1-s peak flux measured from
T0+11.25s was 2.9 photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from
T0-3s to T0+64s is well fitted by a power-law with exponential cutoff model:
dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
alpha 1.2 -0.2 +0.3 and
Epeak 304 -20 +22 keV (chi^2/d.o.f. = 50.6/28).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
GCN Circular 8651
Subject
GRB081203B: optical observations
Date
2008-12-11T05:43:29Z (17 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
T.A. Fatkhullin (SAO RAS, Niznij Arkhyz), E. Sonbas (SAO RAS, Niznij Arkhyz;
University of Cukurova, Turkey), A.J. Castro-Tirado (IAA-CSIC Granada) &
A.Pozanenko (IKI RAS, Moscow) on behalf of larger collaboration, report:
We observed the field of the GRB081203B (P. Schady et al., GCN 8606; Andreev
et al, GCN 8608) in the Rc-band with the 6-m telescope of the SAO RAS in
Caucasus. In total two 3-min exposures were obtained. The optical transient
(OT) is clearly detected in the both images. Using 4 USNO B1.0
stars we estimated the brightness of the OT as
R = 21.81 +/- 0.10 at the epoch of T-T0 = 3.534 days.
We assumed a burst time of 13:52:02 UT (Copete et al., GCN 8600).
Combining our data with ones from the GCN 8608, 8626, 8631 and 8637
we estimate the observed power-law index of the light curve as alpha ~ 1.0.
In the same night we also obtained 2x600sec spectrum of the object near
morning twilight. The VPHG550G grism was used with spectral resolution of
FWHM=10A. Inspection of the integrated spectrum showed no strong emission
lines in the range of 4000-7500AA.
The 3-min R-band image can be downloaded from
ftp://ftp.sao.ru/pub/grb/GRB081203B/GRB081203B_R01.jpg
This message can be cited
[GCN OPS NOTE(13dec08): Per author's request, the ftp url was corrected.]