GRB 081001
GCN Circular 8305
Subject
GRB081001: SuperAGILE Localization of a long GRB
Date
2008-10-01T22:55:08Z (17 years ago)
From
Marco Feroci at IASF/INAF <feroci@iasf-roma.inaf.it>
F. Lazzarotto, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), A. Giuliani, S. Vercellone, A. Chen,
S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, P.
Caraveo (INAF/IASF Milan), A. Bulgarelli, F. Gianotti,
M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi,
M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V.
Vittorini, A. Argan, A. Trois (INAF/IASF Rome), G. Barbiellini,
F. Longo (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2),
M. Prest, E. Vallazza (Universita` dell'Insubria), P. Lipari,
D. Zanello (INFN Roma-1), and P. Giommi, C. Pittori, B. Preger,
P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI),
on behalf of the AGILE Team, report:
"SuperAGILE detected a gamma ray burst on 1st October 2008, at 21:17:42
UT. The event had a duration of about 40 s in the 20-60 keV energy range,
with a first 10-s long bright peak, followed by a second broad peak about
20s apart. Assuming a Crab-like energy spectrum, the peak flux on 1-s
timescale was about 6 ph/cm2/s or 5E-07 erg/cm2/s (20-60 keV).
The burst position was reconstructed as (RA, Dec)
(276.576 deg, -8.754 deg), which is:
RA(J2000) = 18h 26m 18.34s
Dec(J2000) = -8d 45' 14.65"
with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.
An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."
This message may be cited.
GCN Circular 8306
Subject
GRB081001: optical limit from ASH-Centurion
Date
2008-10-02T02:24:13Z (17 years ago)
From
Martin Jelinek at Inst.Astrophys.Andalucia,Granada <mates@iaa.es>
Martin Jelinek, Rene Duffard, Pablo Santos Sanz
and Alberto J. Castro Tirado (IAA CSIC Granada)
report on behalf of a larger collaboration:
We observed the errorbox of the SuperAGILE
GRB081001 (Lazzarotto et al., GCN 8305) with the
40cm ASH-Centurion telescope at Cerro Burek in
Argentina starting at 23:28 UT.
The combined 600s unfiltered image with exposure
mid-time 2.30h after the GRB trigger does not
reveal any new source down to limiting magnitude
of ~19.0 in comparison to the Digitized Sky
Survey.
This message may be cited.
GCN Circular 8307
Subject
GRB 081001: Swift-XRT position
Date
2008-10-02T16:14:48Z (17 years ago)
From
Kim Page at U.of Leicester <kpa@star.le.ac.uk>
K.L. Page (U. Leicester) and H.A. Krimm (CRESST/GSFC/USRA) report on
behalf of the Swift-XRT team:
Swift-XRT started observing the field of the SuperAGILE GRB 081001
(Lazzarotto et al., GCN Circ. 8305) 15.5 ks after the trigger. A single,
fading source was identified within the SuperAGILE error circle, which we
identify as the X-ray afterglow.
Using 4307 s of XRT Photon Counting mode data and 4 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 =
276.59076, -8.71903 which is equivalent to:
RA (J2000): 18 26 21.78
Dec (J2000): -08 43 08.5
with an uncertainty of 2.0 arcsec (radius, 90% confidence).
This circular is an official product of the Swift-XRT team.
GCN Circular 8308
Subject
GRB 081001: Swift UVOT Observations
Date
2008-10-02T17:29:21Z (17 years ago)
From
Erik Hoversten at Swift/Penn State <hoversten@astro.psu.edu>
E. A. Hoversten (PSU), and H.A. Krimm (CRESST/GSFC/USRA) report on
behalf of the Swift UVOT team:
The Swift/UVOT began observations of the field of GRB 081001 14.5 ks
after the SuperAGILE dectection (Lazzarotto et al., GCN
Circ. 8305). No afterglow is detected within the Swift XRT error
circle (Page et al., GCN 8307) in any of the observed UVOT filters.
UVOT magnitude 3-sigma upper limits are reported in the following
table:
Filter T_start T_stop Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------------
v 16285 22214 350 > 19.84
b 15213 21209 416 > 20.90
u 14997 20992 416 > 20.51
uvw1 14568 20776 834 > 20.84
uvm2 16502 16696 191 > 19.81
uvw2 15431 22064 1670 > 21.65
The quoted upper limits have not been corrected for the large expected
Galactic extinction along the line of sight of E(B-V) = 2.63 mag
(Schlegel et al., 1998). All photometry is on the UVOT photometry system
described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular 8310
Subject
GRB 081001: Observations from OSN
Date
2008-10-03T01:29:37Z (17 years ago)
Edited On
2024-11-18T09:54:39Z (7 months ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
A. de Ugarte Postigo (ESO, Santiago), F. Aceituno, M. Jelínek,
J. Gorosabel and A.J. Castro-Tirado (IAA-CSIC, Granada) on
behalf of a larger collaboration report,
We have observed the field of the SuperAGILE GRB 081001
(Lazzarotto et al., GCN 8305) and in particular the Swift/XRT
error box (Page et al., GCN 8307) from the 1.5m OSN telescope
at Sierra Nevada Observatory in Granada (Spain). The
observation consisted of 3x300s I-band exposures with a mean
time of Oct 2.8348 UT (22.7 hours after the burst). We detect just
one source on the edge of the XRT error box, located at the
following coordinates (J2000 +/- 0.7"):
R.A.: 18:26:21.65
Dec.: -08:43:07.6
With a magnitude of I = 19.90+/-0.26 as compared to several
USNO-B1 stars. A finding chart (with the object is marked as A)
can be found in:
http://www.sc.eso.org/~adeugart/GRB/081001/081001.gif
No variability can be established at this point. Rechecking of the
unfiltered image reported by Jelínek et al. (GCN 8306) does not
show any significant emission at the location of the object. Further
observations would be needed in order to determine any relation
of this source with the GRB.
GCN Circular 8322
Subject
GRB 081001: Further observations from OSN
Date
2008-10-04T01:07:27Z (17 years ago)
Edited On
2024-11-18T10:08:42Z (7 months ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
A. de Ugarte Postigo (ESO, Santiago), F. Aceituno, M. Jelínek,
J. Gorosabel and A.J. Castro-Tirado (IAA-CSIC, Granada) on
behalf of a larger collaboration report,
We have observed again the field of GRB 081001 (Lazzarotto et
al., GCN 8305, Page et al., GCN 8307) from the 1.5m OSN
telescope at Sierra Nevada Observatory in Granada (Spain). In a
combined 5x300s exposure in I-band we still detect the source
reported in our previous GCN (de Ugarte Postigo et al. GCN
8310) with no variation in brightness indicating that it is
probably unrelated with the GRB. No further source is detected
within the XRT error box. The 3-sigma limiting magnitudes of
the images obtained from OSN are I > 20.7 0.95 days after the
burst and I > 21.2 1.94 days after the burst.
GCN Circular 8353
Subject
Konus-Wind observation of GRB 081001
Date
2008-10-10T14:05:56Z (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, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:
The GRB 081001 localized by SuperAGILE
(Lazzarotto et al., GCN 8305) triggered Konus-Wind
at T0=76663.649 s UT (21:17:43.649).
The burst light curve shows a main pulse with a duration of ~6 s
followed by a much weaker pulse at T0+~30 s with a duration of ~10 s.
As observed by Konus-Wind the burst
had a fluence of 9.70(-0.86, +1.00)x10^-6 erg/cm2,
and a 64-ms peak flux measured from T0+0.688 s
of 5.63(-1.12, +1.16)x10^-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).
The spectrum of the main pulse
(from T0 to T0+8.448 s) is well 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 = -0.99(-0.18, +0.21),
and Ep = 239(-32, +45) keV (chi2 = 54.9/61 dof).
Fitting by GRBM (Band) model yields:
the low-energy photon index is alpha = -0.95(-0.21, +0.48),
the high energy photon index beta < -2.14,
the peak energy Ep = 227(-70, +52) keV (chi2 = 54.1/60 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.rssi.ru/LEA/GRBs/GRB081001_T76663/