GRB 091102
GCN Circular 10117
Subject
GRB 091102: Swift detection of a burst
Date
2009-11-02T14:43:58Z (16 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
E. A. Hoversten (PSU), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), P.A. Curran (MSSL-UCL), C. Guidorzi (U Ferrara),
J. A. Kennea (PSU), V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB),
P. T. O'Brien (U Leicester), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU),
M. A. Stark (PSU), M. C. Stroh (PSU), T. N. Ukwatta (GSFC/GWU) and
L. Vetere (PSU) report on behalf of the Swift Team:
At 14:34:38 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 091102 (trigger=374598). Swift did not slew immediately
to the burst due to an observing constraint.
The BAT on-board calculated location is
RA, Dec 72.674, -72.510 which is
RA(J2000) = 04h 50m 42s
Dec(J2000) = -72d 30' 34"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 10 sec. The peak count rate
was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger.
Due to an observing constraint, Swift will not slew until
T0+13.6 minutes. There will be no XRT or UVOT data until
this time. We will issue another circular at when those
data are available.
Burst Advocate for this burst is E. A. Hoversten (hoversten AT astro.psu.edu).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular 10118
Subject
GRB 091102: Swift/UVOT Finding Chart Observation
Date
2009-11-02T15:09:46Z (16 years ago)
From
Erik Hoversten at Swift/Penn State <hoversten@astro.psu.edu>
E. A. Hoversten (PSU) reports on behalf of the Swift/UVOT team:
UVOT observed GRB 091102 (Hoversten et al., GCN Circ 10117) with a
finding chart exposure of 150 seconds with the White filter starting
985 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image
covers 25% of the BAT error circle. The 8'x8' region for the list of
sources generated on-board covers 100% of the BAT error
circle. Because of the density of catalogued stars, further analysis
is required to report an upper limit for any afterglow in the
region. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.07.
GCN Circular 10119
Subject
GRB 091102: ROTSE-III Optical Limits
Date
2009-11-02T15:34:52Z (16 years ago)
From
Brad Schaefer at LSU <schaefer@grb.phys.lsu.edu>
B. E. Schaefer (Louisiana State), F. Yuan (U Mich), S. B. Pandey (U Mich),
report on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to
GRB 091102 (Swift trigger 374598; Hoversten et al., GCN 10117), producing
images beginning 5.8 s after the GCN notice time. An automated response
took the first image at 14:35:04.8 UT, 26.5 s after the burst, under fair
conditions with occassional thin clouds and a bright Full Moon 96 degrees
away. We took 10 5-sec, 10 20-sec and 100 60-sec exposures. These
unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on
going.
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle, for both single images and coadding into
sets of 10. No XRT position is available. Individual images have
limiting magnitudes ranging from 13.7-16.0; we set the following specific
limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
14:35:04.8 14:35:09.8 5 14.6 26.5 N
14:35:04.8 14:37:16.8 50 15.5 26.5 Y
14:37:25.9 14:42:08.0 282 16.6 167.6 Y
GCN Circular 10120
Subject
GRB 091102: Swift/XRT localization
Date
2009-11-02T18:42:23Z (16 years ago)
From
Jamie A. Kennea at PSU/Swift-XRT <kennea@astro.psu.edu>
J.A. Kennea, C. Pagani, E.A. Hoversten (PSU), P.A. Evans and M.R. Goad (U.
Leicester) report on behalf of the Swift-XRT team:
Using 289 s of XRT Photon Counting mode data and 1 UVOT images, we find a
possible afterglow candidate with an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources to
the USNO-B1 catalogue): RA, Dec = 72.61610, -72.51970 which is equivalent
to:
RA (J2000): 04 50 27.87
Dec (J2000): -72 31 10.9
with an uncertainty of 2.2 arcsec (radius, 90% confidence), 72 arcseconds
from the BAT position reported by Hoversten et al. (GCN #10117).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
Currently we cannot confirm any fading in this afterglow candidate.
Observations are on-going.
This circular is an official product of the Swift-XRT team.
GCN Circular 10121
Subject
GRB 091102: Swift-BAT refined analysis
Date
2009-11-02T22:06:25Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), E. A. Hoversten (PSU),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 091102 (trigger #374598)
(Hoversten, et al., GCN Circ. 10117). The BAT ground-calculated position is
RA, Dec = 72.622, -72.527 deg which is
RA(J2000) = 04h 50m 29.3s
Dec(J2000) = -72d 31' 37.9"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 80%.
Because the s/c slewed for an observing constraint, the burst location
went out of the BAT FOV at T+160 sec, and then came back into the FOV
at T+900 sec. The mask-weighted light curve shows a couple slightly overlapping
peaks starting at ~T-2 sec, and ending at ~T+20 sec. There is now measurable
flux at T+900 sec when the location comes back into the FOV. T90 (15-350 keV)
is 6.6 +- 0.5 sec (estimated error including systematics).
The time-averaged spectrum from T-0.8 to T+6.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.08 +- 0.12. The fluence in the 15-150 keV band is 5.2 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.26 sec in the 15-150 keV band
is 1.4 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/374598/BA/
GCN Circular 10122
Subject
GRB 091102: BOOTES-3 observations
Date
2009-11-02T23:26:42Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (INAF-OAB), M. Jelinek,
A.J. Castro-Tirado (IAA-CSIC), P. Kubanek (IPL UV, IAA-CSIC),
J. Gorosabel, R. Cunniffe, S. Guziy (IAA-CSIC), P. Yock
(Auckland Univ.), W.H. Allen (Vintage Lane Obs.), I. Bond
(Massey Univ.), G. Christie (Stardome Obs.),
report on behalf of a larger collaboration:
"We have observed the field of GRB 091102 (Hoversten et al.
GCN 10117) with the 0.6m Yock-Allen robotic telescope
(BOOTES-3) in Bleinheim, New Zealand. The observations were
obtained with clear filter and began at 14:35:04 UT (26
seconds after the burst). As stated by Schaefer et al.
(GCN 10119) using ROTSE-III data, there is no obvious
counterpart within the BAT error box. Inspection of the XRT
error circle shows a source at the South-Western edge that
is present both in the DSS and in 2MASS. Combining early
images we detect a further low signal source, with
coordinates (J2000) 04:50:27.22, -72:31:10.3. We note
however, that this is a preliminary reduction and that the
detection cannot be secure at this point. In the following
address we provide a finding chart indicating the location
of the source:
http://www.iaa.es/~mates/091102_BOOTES3.jpg
t-t0(s) Exp(s) Mag
===============================
72 39x2 19.07+/-0.35
406 107x2 19.36+/-0.35
530 60x5 > 19.96
83 19x30 > 19.25
2708 47x60 > 20.30
===============================
For the photometry we have used the star located at the
coordinates (J2000) 04 50 26.58, -72 31 35.3, assuming a
magnitude of 16.14."
[GCN OPS NOTE(02nov09): The Subject-line was changed from 091103
to 091102.]
GCN Circular 10123
Subject
GRB 091102: GROND Upper Limits
Date
2009-11-03T04:21:46Z (16 years ago)
From
Felipe Olivares Estay at MPE <felipe@mpe.mpg.de>
R. Filgas, F. Olivares, T. Kruehler, J. Greiner, (all MPE Garching)
report on behalf of the GROND team:
We observed the field of GRB 091102 (Swift trigger 374598; Hoversten
et al., GCN #10117) simultaneously in g'r'i'z'JHK with GROND (Greiner
et al. 2008, PASP, 120, 405) mounted at the 2.2 m ESO/MPI telescope at
La Silla Observatory (Chile). Observations started on November 3 at
00:02 UT, 9.5 hours after the GRB trigger. They were performed from
the beginning of the astronomical twilight at an average seeing of 2"
and at an average airmass of 2.15.
Although the source at the South-Western edge of the 2.2" Swift/XRT
error circle (Kennea et al., GCN #10120) reported by De Ugarte Postigo
et al. (GCN #10122) is clearly seen, we do not detect the afterglow
candidate in co-added images of 49.2 min integration time in g'r'i'z'
and 40 min in JHK down to the following limiting magnitudes (all in
the AB system):
r' > 23.1 mag,
i' > 22.9 mag,
z' > 23.1 mag,
J > 20.6 mag,
H > 20.5 mag, and
K > 19.0 mag,
calibrated against GROND zeropoints and 2MASS field stars. No
corrections for the expected Galactic foreground extinction were made,
which correspond to a reddening of E(B-V)=0.14 mag in the direction of
the burst (Schlegel et al. 1998).
GCN Circular 10124
Subject
GRB 091102: Swift/UVOT Upper Limits
Date
2009-11-03T05:23:32Z (16 years ago)
From
Erik Hoversten at Swift/Penn State <hoversten@astro.psu.edu>
E. A. Hoversten (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091102
986s after the BAT trigger (Hoversten et al., GCN 10117). We do not
detect any source at the enhanced Swift XRT position (Kennea et
al. GCN 10120). UVOT magnitude 3-sigma upper limits are reported in
the following table:
Filter T_start T_stop Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------------
WHITE 986 1136 147 > 20.05
v 1267 1287 19 > 17.18
b 1193 1213 19 > 18.09
u 1168 1188 19 > 17.70
uvw1 1144 1164 19 > 17.70
uvm2 1292 1301 9 > 16.61
uvw2 1243 1263 19 > 17.79
The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.07 mag
(Schlegel et al. 1998). All photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular 10125
Subject
GRB 091102: Swift-XRT refined analysis
Date
2009-11-03T06:23:30Z (16 years ago)
From
Loredana Vetere at PSU <vetere@astro.psu.edu>
L. Vetere and E. A. Hoversten (PSU) report on behalf of the Swift-XRT
team:
We have analysed 1.4 ks of XRT data for GRB 091102 (Hoversten et al.
GCN Circ.
10117), from 988 s to 19 ks after the BAT trigger. The data are
entirely in
Photon Counting (PC) mode. The enhanced XRT position has already been
determined
by Kennea et al. (GCN Circ. 10120).
The PC light curve shows a steep drop at 1.3 ks after the BAT trigger
with a
decay index of alpha=2.9 +/- 0.6.
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law
with a photon spectral index of 2.0 (+0.8, -0.6). The best-fitting
absorption
column is 2.4 (+2.5, -1.3) x 10^21 cm^-2, consistent with the Galactic
value of
1.1 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed
(unabsorbed)
0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x
10^-11
(6.3 x 10^-11) erg cm^-2 count^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00374598.
This circular is an official product of the Swift-XRT team.
GCN Circular 10127
Subject
GRB 091102 : Faulkes Telescope South Upper Limits
Date
2009-11-03T12:07:11Z (16 years ago)
From
Zach Cano at ARI/John Moores Liverpool <zec@astro.livjm.ac.uk>
Z. Cano (Liverpool JMU), C. Guidorzi (U. Ferrara), A. Melandri, C.G.
Mundell, D.Bersier, N.R. Clay, S. Kobayashi, C.J. Mottram, R.J. Smith,
I.A. Steele (Liverpool JMU), A. Gomboc (U. Ljubljana)on behalf of a larger
collaboration report:
Following Swift detection of GRB 091102 (Hoversten et al. GCN Circ.
10117), Faulkes Telescope South (Australia) reacted automatically and
began observing at 14:37:06 UT in BVRi. We detect no new source within
the XRT error circle (Baumgartner et al., GCN 10121).
In our first R-band image, which is contemporaneous with the images taken
by A. de Ugarte Postigo et al. (GCN 10122), we do not detect their
afterglow candidate.
We have attached a finder chart of the GCN field (taken at T-To=186s):
http://www.fe.infn.it/u/guidorzi/GRB091102/091102_FTS_DM.jpg
We find the following upper limits, as calibrated against nearby USNO
object 0174-0110239:
T_exp T-T0(mid exposure) mag_limit
-----------------------------------------
30s 186 s R2 > 19.7
120s 2.07 hrs B2 > 18.7
120s 2.18 hrs I2 > 20.7
120s 2.12 hrs R2 > 20.2
GCN Circular 10129
Subject
GRB 091102: LABOCA/APEX submm observations
Date
2009-11-03T23:08:08Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (INAF-OAB), A. Lundgren,
C. de Breuck (ESO), A.J. Castro-Tirado, M. Jelinek
(IAA-CSIC) report on behalf of a larger collaboration:
We have observed the field of GRB 091102 (Hoversten et al.,
GCN 10117) with using LABOCA/APEX from Chajnantor
(Chile) at 870 um, under non optimal conditions
(PWV~2.5mm). The observation consisted of 3 hours on target,
with a total integration time of 2.2 hours and mean epoch 14.0
hours after the burst. The r.m.s of the image is 6.3 mJy and
covers the complete BAT error box. In particular, we do not
detect any new source at the location of the XRT position
(Baumgartner et al., GCN 10121).
We acknowledge excellent support from APEX staff, in particular
we thank Francisco Montenegro and Claudio Agurto.
GCN Circular 10132
Subject
GRB091102 : MOA optical upper limit
Date
2009-11-04T16:05:21Z (16 years ago)
From
Kenta Nishimoto at Nagoya U/MOA-II <nishimo@stelab.nagoya-u.ac.jp>
K. Nishimoto, D. Suzuki, T. Sako, and F. Abe (STE Lab, Nagoya Univ.)
on behalf of the MOA Collabration report:
We searched for an optical afterglow of GRB091102 (Hoversten et al. GCN
10117) starting from 14:57:07.8 UT on 2009 Nov 2 (22.5 minuts after the
burst) with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand.
In a single image of a 60sec exposure with a wideband Red filter (center
wavelength ~ 750nm and FWHM ~ 250nm), we did not find any object within
the error circle of the Swift XRT source position (GCN 10120), except a
star reported by BOOTES-3 (De Ugarte Postigo et al. GCN 10122) and GROND
(R. Filgas et al. GCN 10123), which has I mag=19.15 and the separation
of 1.6 arcsec from the center of the position.
A 5 sigma upper limit is set in the I magnitude at 20.8 mag.
This photometry was done by using the DoPhot and calibrated against the
USNO-B1.0 cataloged stars, and not corrected for the Galactic extinction.