- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Sun 26 Oct 03 05:36:11 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 2882, Seq_Num: 1
GRB_DATE: 12938 TJD; 299 DOY; 03/10/26
GRB_TIME: 20143.25 SOD {05:35:43.25} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 136 [cnts/s] on a 5.200 [sec] timescale
SC_-Z_RA: 30 [deg]
SC_-Z_DEC: 12 [deg]
SC_LONG: 204 [deg East]
SUN_POSTN: 210.20d {+14h 00m 48s} -12.30d {-12d 18' 09"}
MOON_POSTN: 219.78d {+14h 39m 07s} -14.62d {-14d 37' 25"}
MOON_ILLUM: 1 [%]
COMMENTS: Probable GRB.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Sun 26 Oct 03 08:51:20 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 2882, Seq_Num: 3
GRB_DATE: 12938 TJD; 299 DOY; 03/10/26
GRB_TIME: 20143.24 SOD {05:35:43.24} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 136 [cnts/s] on a 5.200 [sec] timescale
SC_-Z_RA: 30 [deg]
SC_-Z_DEC: 12 [deg]
SC_LONG: 204 [deg East]
WXM_CNTR_RA: 49.677d {+03h 18m 42s} (J2000),
49.735d {+03h 18m 56s} (current),
48.923d {+03h 15m 42s} (1950)
WXM_CNTR_DEC: +28.366d {+28d 21' 58"} (J2000),
+28.380d {+28d 22' 47"} (current),
+28.184d {+28d 11' 04"} (1950)
WXM_MAX_SIZE: 30.00 [arcmin] diameter
WXM_LOC_SN: 6 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 2.9 Y= 2.4 [sig/noise]
WXM_LC_SN: X= 4.3 Y= 5.0 [sig/noise]
SUN_POSTN: 210.20d {+14h 00m 48s} -12.30d {-12d 18' 09"}
SUN_DIST: 155.70 [deg]
MOON_POSTN: 219.78d {+14h 39m 07s} -14.62d {-14d 37' 25"}
MOON_DIST: 163.44 [deg]
MOON_ILLUM: 1 [%]
GAL_COORDS: 158.26,-24.22 [deg] galactic lon,lat of the burst
ECL_COORDS: 54.71,9.73 [deg] ecliptic lon,lat of the burst
COMMENTS: Definite GRB.
COMMENTS: WXM error box is circular; not rectangular.
COMMENTS: Burst_Validity flag is true.
- GCN notice #2427
D. Budi(University of Tokyo), T. Nakamura(NAOJ), F. Yoshida(NAOJ),
T. Aoki and Y. Urata on behalf of KISO GRB Team report;
" We have observed the entire HETE-2 error circle of GRB031026 (=
H2882) with Kiso observatory 1.05 m Schmidt telescope (Kiso
Observatory, Institute of Astronomy, the University of Tokyo). We
obtained Rc-band data sets (300 sec x 3 frames), starting at Oct 26
11:28 UT. The limiting magnitude for each images is about 18 mag.
Comparison with DSS II red images, no new object was detected down to
the limiting magnitude.
Further observation and analysis are in progress."
This message may be cited.
- GCN notice #2428
M.C. Nysewander, J.A. Moran, D. Reichart (Univ. of North Carolina) & M.
Schwartz (Tenagra Observatories) on behalf of the FUN GRB collaboration
report:
We began observations in Ic of the error box of HETE trigger 2882
(GRB 031026) at 09:30:10 UT (3.9 hrs after the burst) with the 32-inch
Tenagra II telescope. 99% of the error box was covered in four pointings,
with a total integration time of 1350s per pointing.
Comparison to the POSS2 Red & IR images yields no candidates down
to the approximate limiting magnitude of the plates, which we estimate to
be Ic ~ 19.
- GCN notice #2429
GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
N. Butler, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley
on behalf of the HETE Science Team;
T. Donaghy, C. Graziani, E. Fenimore, M. Galassi, M. Matsuoka, T.
Sakamoto, Y. Shirasaki, M. Suzuki, T. Tamagawa, K. Torii, A. Yoshida,
Y. Nakagawa, R. Satoh, Y. Urata, T. Yamazaki and Y. Yamamoto, on
behalf of the HETE WXM Team;
G. Crew, J. Doty, A. Dullighan, G. Prigozhin, R. Vanderspek, J.
Villasenor, J. G. Jernigan, G. Azzibrouck, J. Braga, R. Manchanda,
and G. Pizzichini, on behalf of the HETE Operations and HETE
Optical-SXC Teams;
M. Boer, J-F Olive, J-P Dezalay, C. Barraud, and K. Hurley on behalf
of the HETE FREGATE Team;
report:
At 05:35:43.25 UTC (20143.25 s UT) on 26 October 2003, the HETE
FREGATE and WXM instruments detected event H2882, a faint, long-hard
GRB.
The burst triggered FREGATE in the 25-400 keV energy band. Ground
analysis of the WXM data provided a localization that was reported in
a GCN Notice at 08:51:20 UT, 3.26 hours after the burst. The WXM
ground localization SNR was 6. The WXM localization can be expressed
as a 90% confidence circle, with a radius of 15 arcminutes, centered
at:
WXM-Ground: R.A. = +03h 18m 42s, Dec. = +28d 21' 58" (J2000).
An automated fit of a cutoff power-law spectrum has been performed
for H2882. The fit of the model to the data is posted at
http://space.mit.edu/HETE/Bursts/GRB031026
From the automated fit, the calculated values of Epeak and the burst
fluence (25-100 keV) posted at the above website are:
--Epeak = 330 keV
--Fluence = 2.3e-06 erg/cm^2
--Duration(t90) = 114.2 seconds
Also posted at the above website are the following data, in the
formats described by Vanderspek (GCN 2421):
--Fregate light curve and ascii data tables (energy bands A[7-30
keV], B[7-80 keV], and C[30-400 keV])
--Color-color plot location of H2882 relative to other HETE-localized bursts
--Signal-to-noise histogram location of H2882 in Fregate Band C
relative to other HETE-localized bursts
We note that the counts ratio (Band_B/Band_A > 1.8) for H2882 is one
of the most extreme values yet measured by HETE.
This message may be cited.
- GCN notice #2432
GRB 031026 (=H2882): Evidence for High Redshift from Prompt Emission
J-L. Atteia, G. Ricker, K. Hurley, J. G. Jernigan, N. Kawai, D.
Lamb, and S. Woosley, on behalf of the HETE Science Team;
C. Barraud, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the
HETE FREGATE Team;
T. Donaghy, C. Graziani, E. Fenimore, M. Galassi, M. Matsuoka, T.
Sakamoto, Y. Shirasaki, M. Suzuki, T. Tamagawa, K. Torii, A. Yoshida,
Y. Nakagawa, R. Satoh, Y. Urata, T. Yamazaki and Y. Yamamoto, on
behalf of the HETE WXM Team;
J. Villasenor, N. Butler, G. Crew, J. Doty, A. Dullighan, G.
Prigozhin, R. Vanderspek, G. Azzibrouck, J. Braga, R. Manchanda, and
G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC
Teams;
report:
Careful spectral analysis of the prompt X-ray and gamma-ray emission
of GRB 031026 (Butler et al; GCN 2429) confirms that this burst has a
very hard spectrum. This is unusual for relatively faint, long GRBs
like GRB 030126.
We have computed a "pseudo-redshift" for GRB 031026, based on the
spectral properties of its prompt high energy emission, using the
prescription of Atteia (2003) (see A&A, 407, L1, for the definition
of pseudo-redshift, or pseudo-z). We determine a value of 14 for the
pseudo-z. This value is the highest one amongst the 40 HETE GRBs for
which pseudo-z's have been calculated; only 3 of the 40 have
pseudo-z's greater than 4:
GRB 020305, pseudo-z = 5.9
GRB 010612, pseudo-z = 9.5
GRB 031026, pseudo-z = 14.
For the 10 HETE GRBs with spectroscopic redshifts for which
calculation of a pseudo-z has been possible, the pseudo-z is always
within a factor of two of the spectroscopic redshift. However, this
agreement reflects to some degree the fact that the prescription used
to calculate the pseudo-z's was optimized for these 10 bursts, and it
has not been possible as yet to predict the pseudo-z's of an
independent set of GRBs. Furthermore, the 10 HETE bursts included in
this fit span the redshift range z = 0.2 to z= 3.5, and thus no
calibration of the pseudo-z prescription has yet been possible for a
redshift as large as the pseudo-z value we find for GRB 031026.
Nevertheless, we believe that it is important to report the pseudo-z
we find for GRB 031026, given the possible importance of this burst.
Considering the unusually hard spectrum yet small peak flux of GRB
031026, potentially revealing a source at very high redshift, we urge
observers to perform deep observations of the HETE localization error
circle for this burst (see GCN 2429 for more details) at other than
optical wavelengths. If the source of this burst truly lies at a
very high redshift (z > 7), its optical afterglow could be
undetectable as a result of absorption by the Lyman alpha forest, yet
X-ray and/or IR observations might reveal a counterpart. Furthermore,
at a fixed time of observation after the GRB, the effect of
cosmological time dilation for a very high redshift could in
principle increase the spectral flux in a given frequency band to
such a degree that the afterglow would appear dramatically brighter
than might otherwise be anticipated. Thus, a z=7 afterglow observed
at 8 days after the burst could be as bright (e.g. in a fixed X-ray
or IR band) as would a z=1 afterglow observed at 1 day after the
burst (Lamb and Reichart 2000; Ciardi and Loeb 2000).
This result may be cited.
- GCN notice #2433
M. C. Nysewander, J. A. Moran, C. Zdanowicz, D. Reichart (U. North
Carolina) and M. Schwartz (Tenagra Observatories) report on behalf of the
FUN GRB Collaboration:
We twice observed the error circle of GRB 031026 (Bulter et al., GCN 2429)
with the 32-inch Tenagra II telescope beginning 3.9 hours (Nysewander et
al., GCN 2428) and 25.7 hours after the burst. We covered 99% of the error
circle in four pointings with a total integration time per pointing of 1350
sec for the first epoch and 1500 sec for the second epoch.
Using the image subtraction routine ISIS2 (Alard 2000), we find no
transients to the limiting magnitude of our first epoch image, which we
measure to be Ic = 20.4 mag (3 sigma) using five USNO-B1 stars for
calibration.
Assuming R_V = 3.1, the Galactic extinction along the line of sight is A_Ic
= 1.5 mag.
- GCN notice #2436
GCN Circular
Title: Lulin optical follow-up observations of GRB031026
A.C. Chen, H.C. Ting, H.C. Lin, K.Y. Huang, D. Kinoshita,W.H. Ip(NCU)
Y. Urata and T. Tamagawa (RIKEN) report:
"We have observed the entire region of HETE-2 error circle of
GRB031026 (N. Butler et al. GCN2429) with 1.0-m telescope Lulin
observatory (Institute of Astronomy, National Central University,
Taiwan) at 26.48-26.72 Oct 2003, corresponding 6-12 hours after the
burst. We have imaged 9 fields by CCD camera (10'x10' field of view).
These average limiting magnitudes is about 20.9 (SN=3, compared with
USNO-A2.0 red magnitudes). Comparing with Digitized Sky Survey (DSS2)
image, there are no new object down to the limiting magnitude."
The observation is summarized as follows:
---------------------------------------------------------------------
Field RA DEC Start filter Exp.(sec) Limit mag.
time(UT)
1 03:17:55.5 +28:31:40 11:33 R 300 x 3 21.2
2 03:17:56.8 +28:21:41 11:57 R 300 x 3 20.5
3 03:17:58.1 +28:11:42 12:23 R 300 x 3 20.0
4 03:19:27.2 +28:22:14 12:42 R 300 x 3 20.3
5 03:19:26.0 +28:32:13 13:01 R 300 x 3 21.1
6 03:19:28.4 +28:12:15 13:20 R 300 x 3 21.2
7 03:18:42.0 +28:21:58 17:02 R 300 x 1 21.3
8 03:18:40.8 +28:31:57 17:09 R 300 x 1 20.9
9 03:18:43.2 +28:11:59 17:18 R 300 x 1 21.5
---------------------------------------------------------------------
This message may be cited.
- GCN notice #2440
F. Bertoldi (MPIfR Bonn), D.A. Frail (NRAO), E. Berger (Caltech),
K.M. Menten (MPIfR Bonn), S. Kulkarni (Caltech) report:
We have imaged a ca. 13 arcmin radius field around the WXM localization of
GRB031026 (Butler et al. GCN 2429), using the Max-Planck Millimeter
Bolometer array at the IRAM 30m telescope. We do not find any source
with a 250 GHz (1.2 mm) flux density >16 mJy (4 sigma upper limit)
within 10 armin of this position. The observations were conducted
between UT Oct 10.9 and Nov 2.2. Further details and maps can be found
at
http://www.mpifr-bonn.mpg.de/staff/bertoldi/projects/grb031026
We wish to thank the IRAM staff for their flexibile scheduling of the
telescope, which made these observations possible.
This result may be cited.
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