GRB 091029
GCN Circular 10137
Subject
GRB 091029: Observations from Stardome Observatory
Date
2009-11-05T08:44:38Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
G. W. Christie (Stardome Obs., New Zealand),
S. Dong (IAS, Princeton), A. de Ugarte
Postigo (INAF-OAB, Italy) and T. Natusch
(Stardome Obs., New Zealand) report:
We observed the field of GRB 091029 (Swift
trigger 372210, Grupe et al. GCN 10097) with
the Stardome 0.4m telescope located in
Auckland (New Zealand) starting at 07:55UT,
3.90 hours after BAT trigger. We used a SG530
filter that transmits wavelengths above 5300
Angstroms and a SBIG ST-L-6303E CCD (KAF-6303E
detector).
A nearly continuous series of 300s images was
taken until 16:30UT under mostly clear
conditions (seeing: 1.6-2.5"). These were
co-added making 15 stacks of 6 images (1800s
exposure each).
The fading afterglow (Filgas et al., GCN 10098;
LaCluyze et al., GCN 10099; de Ugarte Postigo
et al., GCN 10104; Marshall et al. GCN 10108)
was clearly detected in all images over the
observing period, yielding the following psf
photometry(DOPHOT):
UT (mid) delT R1 Err (statistical)
29.32713 3.901 19.34 0.09
29.34906 4.428 19.32 0.08
29.37120 4.959 19.43 0.08
29.39311 5.485 19.46 0.08
29.41503 6.011 19.67 0.08
29.43360 6.456 19.57 0.08
29.45862 7.057 19.73 0.08
29.50946 8.277 19.93 0.12
29.53164 8.809 19.94 0.09
29.56044 9.501 20.16 0.09
29.59390 10.304 20.21 0.11
29.61620 10.839 20.21 0.13
29.63853 11.375 20.36 0.16
29.66081 11.910 20.41 0.17
where delT is the mid-exposure time in hours
since trigger. Photometric calibration was
done against USNOB1 0340-0030262 RA (J2000.0):
04h 00m 38.61s, DEC( J2000.0): -55d 55' 37.3"
assuming R1=16.40.
The mean power-law index over this interval
was -0.94 (+/-0.05). Astrometry of the images
gave the afterglow position (UCAC2) as:
RA (J2000.0) = 04h 00m 42.62s
DEC (J2000.0) = -55d 57' 20.2"
with an uncertainty of 0.18"
This position is in agreement with Marshall et
al. (GCN 10108) and Grupe et al. (GCN 10097).
GCN Circular 10111
Subject
GRB 091029, SMARTS optical/IR afterglow observations
Date
2009-10-29T23:30:19Z (16 years ago)
From
Bethany Cobb at UC Berkeley <bcobb@astro.berkeley.edu>
B. E. Cobb (UC Berkeley) reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained
optical/IR imaging of the error region of GRB 091029 (GCN 10097, Grupe et
al.) with a mid-exposure time of 50 minutes post-burst (2009-10-29 04:43
UT). Total summed exposure times amounted to 36 minutes in I and 30
minutes in J. Imaging was done under poor (2.5") seeing conditions.
The afterglow of GRB 091029 (e.g. GCN 10097, Grupe et al.; GCN 10098,
Filgas et al.; GCN 10099, LaCluyze et al.) is detected in our images.
Preliminary comparison to USNO-B1.0 stars in I and 2MASS stars in J
indicates the following afterglow magnitudes:
time post-burst I mag J mag
50 minutes 17.9+/-0.1 17.6+/-0.1
In individual I-band images, the afterglow fades by ~0.4 magnitudes
between 30 and 69 minutes post-burst. During this time, the afterglow
exhibits a shallow decay rate of alpha ~ -0.4+/-0.1 (where afterglow flux
is proportional to t^alpha), which is consistent with the decay rate
measured by LaCluyze et al. (GCN 10099).
GCN Circular 10108
Subject
GRB091029: Swift/UVOT observations
Date
2009-10-29T21:13:14Z (16 years ago)
From
Frank Marshall at GSFC <marshall@milkyway.gsfc.nasa.gov>
F. E. Marshall (GSFC) and D. Grupe (PSU) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091029
91 sec. after the BAT trigger (Grupe et al., GCN Circ. 10097).
We detect the optical afterglow at the refined UVOT position
RA, Dec 60.17745, -55.95557, which is
RA (J2000) 04:00:42.59
Dec (J2000) -55:57:20.0
with an estimated uncertainty of 0.55 arcsec (radius, 90% confidence).
This position is consistent with the enhanced XRT position (Goad
et al., GCN 10102). The detection in the white, v, b and u filters and
not in the UV filters is consistent with the redshift
of 2.752 (Chornock et al., GCN 10053).
The afterglow brightened by a factor of 4 between the first two
observations in the white filter, which had mean observing times
of T+166 s. and T+594s. The afterglow then decayed following
an approximately power law form with a decay index of -0.45.
This decay form lasted until at least T+8231 s.
A similar optical light curve was reported by LaCluze et al.
(GCN Circ. 10099 and 10107).
Preliminary magnitudes and 3 sigma upper limits are reported below.
Filter T_start(s) T_stop(s) Exposure(s) Mag Err
------------------------------------------------------------------------
white 91 240 147 20.22 +/- 0.13
white 584 603 19 18.75 +/- 0.14
v 635 654 19 17.81 +/- 0.26
b 559 578 19 19.04 +/- 0.28
u 303 552 19 18.42 +/- 0.08
uvw1 684 1280 58 > 19.32
uvm2 1930 1949 19 > 18.74
uvw2 611 1206 58 > 20.45
-------------------------------------------------------------------------
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 photometric system
described in Poole et al. (2008, MNRAS, 383,627).
GCN Circular 10107
Subject
GRB 091029: Skynet/PROMPT Continued Observations of Fading
Date
2009-10-29T20:37:05Z (16 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@physics.unc.edu>
A. LaCluyze, D. Reichart, J. Haislip, K. Ivarsen, R. Egger, A. Foster, J.
Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M.
Nysewander report:
Skynet continued to observe the afterglow (Grupe et al., GCN 10097) of GRB
091029 (Grupe et al., GCN 10097) with three of the 16" PROMPT telescopes at
CTIO in BRI.
After peaking in brightness 5 - 6 minutes after the trigger (LaCluyze et
al., GCN 10099) the afterglow continued to fade as a power-law of index
approximately -0.5 (LaCluyze et al., GCN 10099) until at least 4.7 hours
after the trigger.
At 4.7 hours after the trigger, the afterglow's magnitude was I = 18.52 +/-
0.06 (statistical) +/- 0.41 (systematic; calibrated to 125 USNO B1 stars).
Skynet's most recent BRI light curve, calibrated to USNO B1 stars, can be
found here:
http://skynet.unc.edu/grb/grb091029.png
GCN Circular 10106
Subject
GRB 091029: Swift XRT refined analysis
Date
2009-10-29T19:46:14Z (16 years ago)
From
Dirk Grupe at PSU/Swift-XRT <grupe@astro.psu.edu>
D. Grupe (PSU) reports on behalf of the Swift-XRT team:
We have analyzed the first 7 orbits of XRT data of GRB 091029
(Grupe et al. GCN Circ. 10097). The data comprise 69 s in Windowed
Timing (WT) mode and 15727 s in Photon Counting (PC) mode. The
enhanced XRT position has already been determined by Goad et al.
(GCN circ. 10102).
A spectrum formed from the WT mode data can be fitted with an
absorbed power-law with a photon spectral index of 2.30+/-0.08
with an absorption column density consistent with the Galactic
value of 1.14 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode
spectrum (excluding the flare around 300 s after the burst) results
in a slightly flatter X-ray spectrum with Gamma = 2.00+/-0.07.
The light curve (excluding the flares) can be modelled with a
double broken power-law decay with an initial decay slope
alpha-1 = 3.76+0.21-0.19 with the first break at 358+48-31 s
after the trigger followed by a plateau phase with a decay slope
alpha-2 = -0.17+/-0.22 and a second break at 3640+3450-1270 s.
After this break the decay slope is alpha-3 = 0.76+0.06-0.05.
If the afterglow continues to decay with a slope of 0.76, the
predicted count rates 24, 48, and 72 hours after the trigger are
0.033 counts s^-1 or 1.12e-12 ergs s^-1 cm^-2,
0.020 counts s^-1 or 6.80e-13 ergs s^-1 cm^-2,
0.014 counts s^-1 or 4.76e-13 ergs s^-1 cm^-2, respectively.
This circular is an official product of the Swift-XRT team.
GCN Circular 10104
Subject
GRB 091029: BOOTES-3 observations
Date
2009-10-29T15:07:01Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (INAF-OAB), J. Gorosabel (IAA-CSIC),
P. D'Avanzo (INAF-OAB), P. Kubanek (IPL UV, IAA-CSIC),
M. Jelinek, R. Cunniffe, S. Guziy, A.J. Castro-Tirado (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 afterglow of GRB 091029 (Grupe et
al. GCN 10097) using the 0.6m Yock-Allen robotic telescope
(BOOTES-3). A 24x60s combined unfiltered exposure with
mid epoch October 29.450 UT (6.9 h after the burst) shows the
afterglow at a magnitude of R = 18.5 +/- 0.2 as compared to
USNO-B1 star n. 0340-0030266 (RA, Dec = 04:00:39.53,
-55:56:55.17, R2 = 16.66).
A finding chart can be found at:
http://www.brera.inaf.it/utenti/deugarte/GRB/091029/b3_091029.jpg
Further analysis is ongoing.
[GCN OPS NOTE(30oct09): Per author's request, "B.A. Allen"
was changed to "W.H. Allen".]
GCN Circular 10103
Subject
GRB 091029: Swift-BAT refined analysis
Date
2009-10-29T13:30:45Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (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 091029 (trigger #374210)
(Grupe, et al., GCN Circ. 10097). The BAT ground-calculated position is
RA, Dec = 60.166, -55.954 deg, which is
RA(J2000) = 04h 00m 40.0s
Dec(J2000) = -55d 57' 12.7"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
The mask-weighted light curve shows three overlapping peaks, the first starting
at ~T-10 sec, peaking at T+2, +20, and +26 sec, and ending at ~T+70 sec.
T90 (15-350 keV) is 39.2 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T-1.8 to T+60.2 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.46 +- 0.27,
and Epeak of 61.4 +- 17.5 keV (chi squared 49.9 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+19.12 sec in the 15-150 keV band is
1.8 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.88 +- 0.06 (chi squared 57.4 for 57 d.o.f.). 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/374210/BA/
GCN Circular 10102
Subject
GRB 091029: Enhanced Swift-XRT position
Date
2009-10-29T09:22:39Z (16 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 4524 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 091029, 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 = 60.17793, -55.95556 which is equivalent
to:
RA (J2000): 04h 00m 42.70s
Dec (J2000): -55d 57' 20.0"
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
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).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 10100
Subject
GRB 091029: Gemini-South Redshift
Date
2009-10-29T07:49:19Z (16 years ago)
From
Ryan Chornock at UC Berkeley <chornock@astro.berkeley.edu>
R. Chornock, D. A. Perley, and B. E. Cobb (UC Berkeley) report on behalf of a
larger collaboration:
We obtained optical spectra of the afterglow of GRB 091029 (Grupe et al., GCN
10097; Filgas et al., GCN 10098; LaCluyze et al., GCN 10099) using GMOS on
Gemini-South. Our spectra cover the wavelength range of 3900-8100 angstroms
with the R400 grating. Our first 600s exposure, starting at 06:06 UT on Oct. 29
(2.2 hr after the BAT trigger) reveals absorption lines from Lyman-alpha, C II,
C IV, Si II, and Si IV at a common redshift of 2.752, which we identify as
the redshift of the GRB. The afterglow is still quite bright (R~17.8 mag at
t=2.02 hr) in the acquisition image.
We would like to thank German Gimeno and the Gemini staff for their assistance.
GCN Circular 10099
Subject
GRB 091029: Skynet/PROMPT Observations of Peak and Fading
Date
2009-10-29T06:56:42Z (16 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@physics.unc.edu>
A. LaCluyze, D. Reichart, K. Ivarsen, J. Haislip, R. Egger, A. Foster, J.
Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M.
Nysewander report:
Skynet observed the Swift/BAT localization of GRB 091029 (Grupe et al., GCN
10097) with three of the 16" PROMPT telescopes at CTIO beginning 46 seconds
after the trigger in BRI through variable winds.
We detect the afterglow (Grupe et al., GCN 10097) in all filters.
The afterglow peaked in brightness approximately 5 - 6 minutes after the
trigger, after which it has been fading with a power-law index of about
-0.5.
GCN Circular 10098
Subject
GRB 091029: GROND Detection of the Optical/NIR Afterglow
Date
2009-10-29T04:42:35Z (16 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
Robert Filgas (MPE Garching), Adria Updike (Clemson University), and
Jochen Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 091029 (Swift trigger 374210; Grupe et al.,
GCN #10097) 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 at 03:57 UT on Oct 29, 4.5 min after the GRB trigger,
and are continuing. They were performed at an average seeing of 1.6" and
at an average airmass of 1.22.
We found a single point source within the 4.8 Swift-XRT error circle
reported by Grupe et al. (GCN #10097) at
RA (J2000.0) = 04h 00m 42.7 s
DEC (J2000.0) = -55d 57' 19
with an uncertainty of 0.5".
Based on the first 5.3 min of total exposures in g'r'i'z' and 6.7 min in
JHK, we estimate preliminary magnitudes (all in AB system) of
g' = 17.72 +- 0.1 mag,
r' = 17.45 +- 0.1 mag,
J = 17.00 +- 0.08 mag.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.02 mag in the
direction of the burst (Schlegel et al. 1998).
GCN Circular 10097
Subject
GRB 091029: Swift detection of a burst with an optical counterpart
Date
2009-10-29T04:05:12Z (16 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
D. Grupe (PSU), J. R. Cummings (NASA/UMBC),
F. E. Marshall (NASA/GSFC), C. Pagani (PSU), D. M. Palmer (LANL),
M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC),
T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the
Swift Team:
At 03:53:22 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 091029 (trigger=374210). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 60.183, -55.994 which is
RA(J2000) = 04h 00m 44s
Dec(J2000) = -55d 59' 37"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a double-peaked
structure with a duration of about 50 sec. The peak count rate
was ~3000 counts/sec (15-350 keV), at ~18 sec after the trigger.
The XRT began observing the field at 03:54:41.9 UT, 79.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 60.17774, -55.95574 which
is equivalent to:
RA(J2000) = 04h 00m 42.66s
Dec(J2000) = -55d 57' 20.7"
with an uncertainty of 4.4 arcseconds (radius, 90% containment). This
location is 138 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.14e+20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 1.80e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 90 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 04:00:42.58 = 60.17742
DEC(J2000) = -55:57:20.0 = -55.95555
with a 90%-confidence error radius of about 0.70 arc sec. This position is 2.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
20.31 with a 1-sigma error of about 0.18. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02.
Burst Advocate for this burst is D. Grupe (grupe 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.)