GRB 071011
GCN Circular 6882
Subject
GRB 071011: Swift detection of a burst
Date
2007-10-11T12:51:21Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), O. Godet (U Leicester),
S. T. Holland (CRESST/USRA/GSFC), V. Mangano (INAF-IASFPA),
C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Romano (Univ. Bicocca & INAF-OAB), B. Sbarufatti (INAF-IASFPA),
M. Stamatikos (NASA/ORAU), E. Troja (INAF-IASFPA) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:
At 12:40:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 071011 (trigger=293924). Swift did not execute an immediate slew
because of an Earth-observing constraint, but it will at ~T+2700 sec.
The BAT on-board calculated location is
RA, Dec 8.400, +61.072 which is
RA(J2000) = 00h 33m 36s
Dec(J2000) = +61d 04' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows two peaks each of
~10 sec duration. The second peak is at ~T+48 sec.
The peak count rate was ~1800 counts/sec (15-350 keV), at ~1 sec
after the trigger.
Because of an Earth limb constraint, the spacecraft did not slew promptly
to the BAT position, and so there are no immediate XRT data products
to analyze. The UVOT is currently in safe and will not observe this burst.
Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov).
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 6883
Subject
GRB 071011: Optical afterglow candidate
Date
2007-10-11T13:58:13Z (18 years ago)
From
Daniel Perley at U.C. Berkeley <dperley@astro.berkeley.edu>
D. A. Perley, J. S. Bloom, M. Modjaz, and D. Kocevski (UC Berkeley) report:
We slewed to the afterglow position with the Keck I telescope (+LRIS)
and began taking imaging exposures at 12:50:58 UT, ten minutes after the
trigger. By visual comparsion with the DSS we identify a faint
candidate optical afterglow at the position:
RA = 00:33:47.412
dec = +61:03:34.09
Further observations of the afterglow candidate are ongoing.
GCN Circular 6886
Subject
GRB 071011: NAYUTA Optical Observation
Date
2007-10-11T16:56:46Z (18 years ago)
From
Ryo Iizuka at NHAO <iizuka@nhao.go.jp>
R. Iizuka and S. Maeno report on behalf of NHAO.
We observed the field of GRB 071011 (GCN 6882) with MINT
on the 2.0-m NAYUTA telescope at Nishi-Harima Astronomical
Observatory, Japan. We took images for a total of 3000 sec in
R-band filter on 2007 Oct 11 13:36 UT (56 minutes after the burst).
We detect the afterglow reported by GCN 6883 (Daniel Parley et al.).
We estimate a preliminary magnitude of R~22 mag relative to
USNO-B1.0 stars.
GCN Circular 6887
Subject
GRB 071011: Early Super-LOTIS Observations
Date
2007-10-11T17:36:50Z (18 years ago)
From
Grant Williams at Steward Observatory <ggwilli@mmto.org>
G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of
the Super-LOTIS Collaboration, report:
The robotic 0.6-m Super-LOTIS telescope began observing the error box of
GRB 071011 (Swift Trigger 293924, Marshall et al. GCN 6882) at 12:40:53.4 UT,
40.4 seconds after the trigger. Our initial observations include 5 x 10s
exposures, 5 x 20s exposures, and 30 x 60s exposures, all in the R-band.
The observations occurred during morning twilight at a starting airmass
of 2.16. In our earliest exposure, we do not detect the afterglow
candidate reported by Perley (GCN 6883) and confirmed by Iizuka (GCN 6886)
or any other candidates in the BAT error circle to the following
3-sigma limiting magnitude determined from nearby USNO-B1.0 stars:
t_start (UT) exp t (s) t_start-t_0 (s) Limit
--------------------------------------------------------
12:40:53.4 10.0 40.4 R > 16.90
Subsequent exposures also do not reveal any additional candidates.
Analysis is ongoing.
GCN Circular 6889
Subject
GRB 071011, Swift-BAT refined analysis
Date
2007-10-11T18:19:12Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. Sakamoto (GSFC/UMBC), S.D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), F.E. Marshall (GSFC), D. Palmer (LANL),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-119 to T+183 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 071011 (trigger #293924)
(Marshall, et al., GCN Circ. 6882). The BAT ground-calculated position is
RA, Dec = 8.395, 61.132 deg which is
RA(J2000) = 0h 33m 34.8s
Dec(J2000) = 61d 07' 57"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.
The mask-weighted light curve shows two roughly symmetric peaks. The first
starts at ~T-10 sec, peaks at ~T+1 sec, and reachs a minimum at ~T+30 sec.
The second picks up at the minimum at ~T+30 sec, peaks at ~T+46 sec, and
ends at ~T+90 sec. T90 (15-350 keV) is 61 +- 1 sec (estimated error
including systematics).
The time-averaged spectrum from T-9.5 to T+63.8 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.41 +- 0.12. The fluence in the 15-150 keV band is 2.2 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+45.98 sec in the 15-150 keV band
is 1.7 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
GCN Circular 6891
Subject
GRB 071011: XRT afterglow detection
Date
2007-10-11T18:24:21Z (18 years ago)
From
Boris Sbarufatti at INAF-IASF-Pa <sbarufatti@ifc.inaf.it>
B. Sbarufatti, V. La Parola, E. Troja, V. Mangano (INAF-IASFPA),
J. Kennea (PSU), F.E. Marshall (GSFC) report on behalf of the
Swift-XRT team.
We have analyzed the first orbit of XRT data of the Swift
observation of GRB 071011 (Marshall et al., GCN 6882), started
at 13:28:40 UT.
We have a 1600 sec exposure in PC mode. We detect a single
uncatalogued bright source within the XRT field of view,
across an hot column, at position
RA, Dec= 8.3887, +61.1325 deg which is
RA(J2000)= 0h 33m 33.30s
Dec(J2000)= +61d 07' 57.3"
with an uncertainty of 4.4 arcsec (90% containment radius). This
is 11 arcsec from the BAT refined position (Sakamoto et al,
GCN 6889). We remark that the new BAT error circle excludes the
optical afterglow candidate reported by Perley et al. (GCN 6883).
A quick look to the XRT light curve gives a flat behavior at the
level of 0.3 counts/sec. We wait for more data to improve our
analysis.
GCN Circular 6894
Subject
GRB 071011: MARGE Optical Limits
Date
2007-10-11T21:17:44Z (18 years ago)
From
Heather Swan at U.of Michigan/ROTSE <hflewell@umich.edu>
H. Swan (U Mich), I. Smith (Rice), C. Akerlof (U Mich), and M.
Skinner (Boeing) report on behalf of the MARGE collaboration:
The AEOS Burst Camera (ABC) on the AEOS telescope, located at the Maui
Space Surveillance System on Haleakala, observed the field of GRB071011
(Swift trigger 293924 (F. E. Marshall et al, GCN 6882)). The images are
unfiltered 10s exposures which started ~6 minutes after the trigger and
ended ~ 1 hour later. We see the OT candidate observed by Perley et al
(GCN 6883), but it does not fade (between 6-60 minutes).
The first image which contains the XRT position (B. Sbarufatti et al,
GCN 6891) occurred at 20 minutes after the Swift trigger. We coadded
the ABC images into sets of 10 and observe three distinct closely spaced
stellar objects within 7 arc-seconds of the XRT coordinates given in GCN
6891. These appear to be consistent with a set of unresolved stars in
the DSS plates (second epoch) suggesting that no new sources have been
found within the 3-sigma XRT error circle.
GCN Circular 6895
Subject
GRB 071011: P60 Optical Afterglow Candidate
Date
2007-10-11T23:17:00Z (18 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (Caltech) reports on behalf of a larger collaboration:
We have imaged the field of GRB071011 (Marshall et al.; GCN 6882) with the
automated Palomar 60-inch telescope (P60). Observations began at 12:43:38
UT on October 11 (205 s after the burst) and we were able to obtain 3 x 60
s images in the R, i', and z' filters before closing due to twilight.
Based on comparison with the Digital Sky Survey plates, we do not find any
new sources inside the XRT error circle (Sbarufatti et al.; GCN 6891), as
was reported by Swan et al. (GCN 6894). However, slightly outside the XRT
error circle (~ 8" away), we detect a stationary, fading source at
coordinates (J2000.0):
RA: 00:33:32.74 Dec: +61:08:04.4
In our initial R-band exposure, we measure a magnitude of R=17.92, using
several stars from the USNO-B catalog for photometric calibration. The
source fades by over a magnitude in each filter over the duration of our
observations. We therefore consider this likely to be the optical
afterglow of GRB071011.
GCN Circular 6896
Subject
GRB 071011: Kanazawa Optical limits
Date
2007-10-12T01:22:20Z (18 years ago)
From
Daisuke Yonetoku at Kanazawa U <gcn@astro.s.kanazawa-u.ac.jp>
T. Kidamura, S. Tanabe, Y. Okuma, S. Yokota, T. Nashimoto, T. Fujinaga,
H. Fujimoto, R. Edamura A. Wada, T. Murakami and D. Yonetoku
(Kanazawa Univerasity) report on behalf of the Kanazawa GRB team
The robotic Kanazawa 0.4-m telescope imaged the field of GRB 071011
(Marshall et al. GCN 6882) at 190 seconds after the burst trigger.
We observed the field in unfiltered 10x 30s exposure.
Based on comparison of our initial image with the DSS plate, we do
not detect any source inside the XRT error circle (Sbarufatti et al.
; GCN 6891, Swan et al. 6894), and also we do not detect the source
reported by Cenko (GCN 6895) . Our upper limit is ~17.6 under the poor
sky condition.
GCN Circular 6898
Subject
GRB 071011: Confirmation of P60 optical afterglow
Date
2007-10-12T01:57:39Z (18 years ago)
From
Daniel Perley at U.C. Berkeley <dperley@astro.berkeley.edu>
D. A. Perley, D. Kocevski, D. Poznanski, J. S. Bloom, and M. Modjaz (UC
Berkeley) report:
We have performed further analysis of our LRIS imaging of GRB 071011
(Marshall et al., GCN 6882).
The afterglow candidate we reported previously (GCN 6883) does not vary
by more than 0.1 magnitude between 13:01 and 14:22 UT, and is therefore
unlikely to be the optical afterglow of GRB 071011.
Our earliest-time LRIS images do not cover the position of the X-ray
source reported by Sbarufatti et al. (GCN 6891) due to the large offset
between the initial BAT position and XRT position. We returned to the
field starting at 14:10:52 UT and acquired 2x120s in R-band and 2x120s
in the RG850 filter through high airmass. No new objects are detected
within the XRT error circle to an approximate limiting magnitude (3
sigma) of R~24.5.
We do detect a source at the location reported by Cenko et al. Our
position of this source (J2000), relative to the USNO B1.0 catalog, is:
RA = 00:33:32.731
dec = +61:08:04.57
The relative astrometric uncertainty is <0.5".
We calculate a preliminary magnitude of R = 20.4 +/- 0.1 relative to
five nearby USNO stars. Comparison to the magnitude reported by Cenko
et al. (GCN 6895) indicates that the source has faded significantly and
confirms that this is the optical afterglow of GRB071011.
GCN Circular 6899
Subject
GRB 071011, Optical afterglow
Date
2007-10-12T07:10:43Z (18 years ago)
From
Shashi Bhushan Pandey at ARIES, INDIA <shashi@aries.ernet.in>
S. B. Pandey, K Misra and Rupak Roy (ARIES, NainiTal, India, on behalf of l=
arger Indian GRB collaboration)
We observed Swift GRB 071011 with 1.04m telescope NainiTal starting ~
4.0 hours after the burst (Marshall et al. GCN 6882). Observations were
performed in R_c and I_c filters.
Photometry of the co-added I_c frames (300 sec x 6) marginally detects
the afterglow candidate (I_c ~ 20.0) reported by Cenko S. B. (GCN 6895)
in comparison to nearby USNO stars.
This message may be cited.
GCN Circular 6900
Subject
GRB 071011: NAYUTA Optical Observation, correction to GCN6886
Date
2007-10-12T12:30:17Z (18 years ago)
From
Ryo Iizuka at NHAO <iizuka@nhao.go.jp>
R. Iizuka and S. Maeno report on behalf of NHAO.
We observed the field of GRB 071011 (GCN 6882) with MINT
on the 2.0-m NAYUTA telescope at Nishi-Harima Astronomical
Observatory, Japan. We took images in R-band on 2007 Oct 11 13:36 UT
(56 minutes after the burst).
We detect a source at the position reported by Cenko et al.
(GCN 6895). We estimate a preliminary magnitude relative to
the USNO B1.0 catalog. The source fades over our observations,
as was reported by Perley et al. (GCN 6898).
start(UT) exp(sec) R-mag err
--------------------------------------------
13:36:23 300 20.3 0.2
14:37:37 300 21.0 0.2
--------------------------------------------
GCN Circular 6902
Subject
GRB 071011: Swift-XRT refined analysis
Date
2007-10-12T15:07:59Z (18 years ago)
From
Boris Sbarufatti at INAF-IASF-Pa <sbarufatti@ifc.inaf.it>
B. Sbarufatti, V. Mangano, V. La Parola, E. Troja (INAF-IASFPA),
P. Evans, A. Beardmore (U Leicester), D. N. Burrows (PSU),
F. E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team
We have analysed the first orbits of Swift-XRT data obtained for
GRB 071011 (trigger=293924, GCN 6882). The observation consists
of 6.6 ks exposure in Photon Counting (PC) mode, starting 2.7 ks
after the trigger. The GRB afterglow is clearly detected inside
the XRT field of view (FoV) at a large off axis angle only in the
initial 1.6 ks. During the following 5 ks the source was outside
the FoV because of an incorrect spacecraft pointing.
Using an improved algorithm that takes into account the presence
of the underlying hot column we obtain a refined position of:
RA, Dec= 8.38816, 61.13327 (degrees)
RA(J2000)= 00h 33m 33.1s
Dec(J2000)= +61d 07' 59.77"
with an estimated uncertainty radius of 4.1 arcsec (90% containment
radius). This is 2.7 arcsec away from the previous XRT position
(GCN 6891) and 5.5 arcsec away from the optical afterglow reported
by Cenko (GCN 6895) and Perley et al. (GCN 6898). We note that the
position uncertainty of 4.1 arcseconds includes both systematic and
statistical uncertainty, but the systematic component may be
underestimated for a source this close to the edge of the field of
view.
The light curve shows a behavior consistent with a powerlaw decay
with slope -1 +/- 0.7. Due to the large uncertainty we need more
data to constrain the afterglow evolution.
The spectrum extracted from the initial 1.6 ks PC data can be
modelled with an absorbed power-law with photon index
Gamma = 2.6 +/- 0.5, and an absorbing column of
NH = (1.5 +/- 0.7)E22 cm-2, in excess with respect to the Galactic
value of 5.18E21 cm-2. The observed (unabsorbed) flux is
1.26 (6.00)E-11 ergs cm-2 s-1.
All errors are quoted at 90% confidence level.
Additional X-ray observations planned for Oct 14-15 should help
improve both the counterpart position accuracy and the measurement
of the decay rate and spectral parameters.
This circular is an official product of the Swift-XRT team.
GCN Circular 6904
Subject
GRB 071011: Xinglong TNT Optical afterglow observations
Date
2007-10-12T19:51:41Z (18 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L.P. Xin, M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,
Y. Urata, and W.K. Zheng on behalf of EAFON report:
We have observed GRB 071011 beginning at 12:46:05.3 UT,
353s after the burst with TNT 80cm and EST 1m telescopes
at xinglong Observatory, A series of Whiete, R and V band
images were obtained, preliminary analysis shows the
optical afterglow reported by S. B. Cenko (GCN 6895), faded
continuly. Derived from USNO-A2.0 R magnitude,
We find the early time White band magnitude:
---------------------------------------------------
(sec after the burst ) magnitude merr
363.053 17.88143 0.08
407.981 18.02971 0.09
498.701 18.28329 0.10
657.677 18.52271 0.10
834.797 19.55457 0.08
Further analysis is under going.
This message may be cited.
GCN Circular 6905
Subject
GRB 071011: Optical Limit after 13.95hrs
Date
2007-10-13T01:54:53Z (18 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im, I. Lee (Seoul National University), and Y. Urata
(Saitama University) on behalf of the EAFON team:
Using the Mt. Lemmon (Arizona, US) 1.0m telescope
operated by the Korea Astronomy Space Science Institute,
we observed the field of GRB071011 (GCN 6882,
Barthelmy et al.) beginning at 02:37:30 UT on Oct 12,
or 13.95 hrs after the trigger.
A stacked image of 11, 5 min frames in the R-band
does not show the OT reported by Cenko et al. (6895),
Perley et al. (6898), Pandey et al. (6899), Iizuka
et al. (6900), and Xin et al. (6904).
Using USNO B1.0 R2mag of stars for photometric calibration,
we place the upper limit of the OT as R > 21.9 mag
(3-sigma, 6" aperture mag) 13.95 hrs after the trigger.
It appears that the OT faded beyond the R limit.
t_start (UT) Filter exp (sec) R-mag
-----------------------------------------------------
02:37:30 R 11x300 > 21.9mag (3-sigma)
We will report later, a more careful analysis of the BVRI
images taken during the same period.
GCN Circular 6914
Subject
VLA non-detection of GRB 071011
Date
2007-10-14T17:45:25Z (18 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
P. Chandra (UVA/NRAO) and D. A. Frail (NRAO) report on behalf of the
Caltech-NRAO-Carnegie GRB Collaboration:
"We observed the field centered on the P60 position (GCN#6895) of the
Swift burst
GRB 0701011 (GCN#6882) using the VLA at a frequency of 8.46 GHz
and starting at 4.03 UT on Oct 13, 2007. We do not detect any radio
emission
at P60 position of the afterglow (GCN#6895). The flux density at
afterglow position is -14 � 60 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 6922
Subject
GRB 071011: MITSuME Optical Observations
Date
2007-10-16T14:41:48Z (18 years ago)
From
Nobuyuki Kawai at Tokyo Tech <nkawai@hp.phys.titech.ac.jp>
D. Kuroda, K. Yanagisawa, M. Yoshida (NAOJ), T. Ishimura, and N. Kawai
(Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB071011 (Marshall et al., GCN 6882) with
the 3-color 50cm MITSuME Telescope at Okayama Astrophysical
Observatory, and 3-color 105cm Telescope at Ishigakijima Astronomical
Observatory. The observations started at 12:50:06 Oct.11 (9m53s after
the trigger) at Okayama, and at 13:04:15 Oct.11 (24m02s after the
trigger) at Ishigakijima.
In the co-added images of Ic and Rc bands (Okayama), and
Ic, Rc, and V bands (Ishigakijima), we detected the optical
afterglow reported by Cenko et al. (GCN 6895).
We estimate the magnitudes relative to the USNO B1.0 catalog.
The results are followings.
### Results at Okayama ###
start end Exposure Ic mag Rc mag
-------------------------------------------------------
12:50:06 13:00:06 10 x 60 s 18.2 +/- 0.4 19.0 +/- 0.3
13:02:48 13:12:48 10 x 60 s 19.2 +/- 0.4 19.5 +/- 0.4
13:15:26 13:25:26 10 x 60 s 19.3 +/- 0.4 --
-------------------------------------------------------
### Results at Ishigakijima ###
start end Exposure Ic mag Rc mag V mag
-----------------------------------------------------------------------
13:04:15 13:19:14 5 x 60 s 18.6 +/- 0.2 20.1 +/- 0.2 --
13:25:17 13:58:09 5 x 60 s 19.1 +/- 0.4 19.9 +/- 0.2 --
13:04:15 13:58:09 10 x 60 s -- -- 21.0 +/- 0.5
------------------------------------------------------------------------