GRB 111107A
GCN Circular 12534
Subject
GRB 111107A: Swift detection of a burst with an optical counterpart
Date
2011-11-07T01:00:10Z (14 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
M. H. Siegel (PSU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC),
B. Sbarufatti (INAF-OAB/IASFPA), C. A. Swenson (PSU) and
T. N. Ukwatta (MSU) report on behalf of the Swift Team:
At 00:50:24 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111107A (trigger=507185). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 129.484, -66.506 which is
RA(J2000) = 08h 37m 56s
Dec(J2000) = -66d 30' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single FRED-like
peak with a duration of about 15 sec. The peak count rate
was ~1600 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 00:51:28.8 UT, 64.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 129.47682,
-66.52012 which is equivalent to:
RA(J2000) = 08h 37m 54.44s
Dec(J2000) = -66d 31' 12.4"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 51 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 in excess of the Galactic value (8.93 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.6
(+2.29/-1.97) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 4.37e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 73 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 08:37:54.66 = 129.47775
DEC(J2000) = -66:31:12.3 = -66.52009
with a 90%-confidence error radius of about 0.65 arc sec. This position is 1.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.21 with a 1-sigma error of about 0.16. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.14.
Burst Advocate for this burst is M. H. Siegel (siegel 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 12535
Subject
Skynet observations of GRB 111107A
Date
2011-11-07T03:33:45Z (14 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@email.unc.edu>
A. LaCluyze, J. Haislip, K. Ivarsen, D. Reichart, M. Nysewander, J. Moore,
A. Trotter, R. Egger, A. Foster, A. Oza, T. Cromartie, E. Speckhard, and J.
A. Crain report:
Skynet observed the field of GRB 111107A, Swift trigger 507185, with the
PROMPT telescopes located at CTIO in Chile. We detect a fading optical
source within the error circle. Preliminary calibration to USNO catalog
stars yields the follow initial detections:
Tmean(min) Tmean(day) Tel Exp Filt Mag S/N
14.75 m 0.01024 Prompt4 5 x 80 s R 19.467 2.892
15.22 m 0.01057 Prompt5 4 x 80 s I 18.444 4.363
Further observations are ongoing. This message may be cited.
GCN Circular 12536
Subject
GRB 111107A: GROND observations
Date
2011-11-07T04:36:54Z (14 years ago)
From
Thomas Kruehler at Dark Cosmology Center <tom@dark-cosmology.dk>
T. Kruehler (DARK/NBI), A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg) and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of the Swift GRB 111107A (Siegel et al., GCN 12534) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPI/ESO telescope at La Silla Observatory (Chile).
Observations started on November 7, 2011, 03:28 UT as soon as the field of GRB 111107A rose above the pointing constraints of the telescope. This is roughly 2.6 hrs after the trigger.
We detect the afterglow candidate reported by Siegel et al. (GCN 12534) and LaCluyze et al. (GCN 12535). Based on an exposure time of 460 s, we estimate a preliminary r'-band magnitude (in the AB system) of:
r' = 21.3 +/- 0.1
at a midtime of 03:41 UT. The r' band magnitude has been calibrated against the GROND zeropoint.
GCN Circular 12537
Subject
GRB 111107A: Gemini-South Redshift
Date
2011-11-07T06:31:01Z (14 years ago)
From
Ryan Chornock at Harvard <rchornock@cfa.harvard.edu>
R. Chornock, E. Berger (Harvard), and D. Fox (Penn St.) report:
We obtained spectroscopy of the optical afterglow of GRB 111107A (Siegel
et al., GCN 12534; LaCluyze et al., GCN 12535; Kruehler et al., GCN
12536) using GMOS-South on the Gemini-South 8-m telescope. Observations
began at 05:05 UT (4.2 hrs after the BAT trigger). Inspection of the
first two exposures (range 4160-8140 Angstroms) reveals a damped
Lyman-alpha absorber as well as narrow absorption lines of C IV, Al II,
and C II at a common redshift of 2.893.
GCN Circular 12538
Subject
GRB 111107A: Enhanced Swift-XRT position
Date
2011-11-07T06:51:41Z (14 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1642 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 111107A, 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 = 129.47666, -66.51988 which is equivalent
to:
RA (J2000): 08h 37m 54.40s
Dec (J2000): -66d 31' 11.6"
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 12539
Subject
GRB 111107A: Swift-BAT refined analysis
Date
2011-11-07T13:02:54Z (14 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),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. H. Siegel (PSU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 111107A (trigger #507185)
(Siegel, et al., GCN Circ. 12534). The BAT ground-calculated position is
RA, Dec = 129.487, -66.520 deg, which is
RA(J2000) = 08h 37m 56.8s
Dec(J2000) = -66d 31' 12.0"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.
The mask-weighted light curve shows a FRED peak starting at ~T-1 sec,
peaking at ~T+2 sec, and returning to baseline at ~T+55 sec. At the 2-sigma
level, there is a possible peak from T+130 to T+180 sec. There is no hint
of a peak in the T+250 to T+400 sec range corresponding to the flare seen
in the XRT afterglow lightcurve. T90 (15-350 keV) is 26.6 +- 6.6 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.06 to T+32.83 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.49 +- 0.14. The fluence in the 15-150 keV band is 8.8 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.16 sec in the 15-150 keV band
is 1.2 +- 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/507185/BA/
GCN Circular 12540
Subject
GRB 111107A: Swift/UVOT Afterglow Analysis
Date
2011-11-07T14:21:50Z (14 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (MSSL-UCL) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of
GRB 111107A 73 s after the BAT trigger (Siegel et al.,
GCN Circ. 12534).
Preliminary detections and 3-sigma upper limits using the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627)
for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 73 223 147 19.45 +/- 0.10
v 615 1755 136 >18.7
b 540 1681 117 >20.0
u 285 1656 343 >19.9
w1 664 1631 117 >19.2
m2 639 5231 299 >19.7
w2 590 1730 136 >20.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.14 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 12541
Subject
GRB 111107A: APEX submm observation
Date
2011-11-07T15:30:22Z (14 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), R. J. Cumming, A. O. Henrik Olofsson, P. Bergman (OSO), Felipe McAuliffe, M. Martinez (ESO) and A. Lundgren (ESO/ALMA) report on behalf of a larger collaboration:
We have observed the field of GRB 111107A (Siegel et al., GCN 12534) using LABOCA/APEX at Chajnantor (Chile) in the 345 GHz band. The observation consisted of 241 min on source, observed between 3:41 and 10:08 UT (between 2.85 and 9.3 hr after the burst) using the imaging mode. Weather conditions were good, with precipitable water vapour ranging between 0.5 and 0.8. In a preliminary reduction we do not detect any source at the position of the afterglow. The r.m.s. of the image is ~6 mJy, giving a 3-sigma detection limit of 18 mJy.
GCN Circular 12542
Subject
GRB 111107A: VLT/X-shooter spectroscopy
Date
2011-11-07T16:32:22Z (14 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo (INAF-OAB), S. D. Vergani (INAF-OAB), H. Flores (GEPI/Obs. de
Paris), D. Malesani, D. Watson (DARK/NBI), A. J. Levan (Univ. Warwick), J. P. U.
Fynbo (DARK/NBI), report on behalf of a larger collaboration:
We observed the optical afterglow of GRB 111107A (Siegel et al., GCN
12534; LaCluyze et al., GCN 12535; Kruehler et al., GCN 12536; Kuin et
al., GCN 12540), using the X-shooter spectrograph mounted on the ESO-VLT.
Observations started on 2011 November 7.254 UT (5.26 hr after the GRB),
with a total exposure time of 1.3 hr, covering the wavelength range
3000-25000 AA.
In the spectra (reduced with archival calibration files) we detect several
absorption lines, like Ly-alpha, CIV, FeII and MgII, and the correspondent
Lyman limit absorption, at a redshift consistent with that reported by
Chornock et al. (GCN 12537).
We also note the presence of a strong intervening Mg II system at z = 1.998.
We acknowledge excellent support from the observing staff in Paranal, in
particular Valentin Ivanov, Petr Kabath, Jonathan Smoker, Claudia Cid,
Sergio Vera, Christophe Martayan and Roger Wesson.
[GCN OPS NOTE(07nov11): The afilliation of DM and DW was changed.]
GCN Circular 12543
Subject
GRB 111107A: Swift-XRT refined Analysis
Date
2011-11-07T17:40:49Z (14 years ago)
From
Binbin Zhang at PSU <bbzhang@psu.edu>
Bin-Bin Zhang (PSU) reports on behalf of the Swift-XRT team:
We have analysed 12 ks of XRT data for GRB 111107A (Siegel et al. GCN
Circ. 12534), from 55 s to 30.6 ks after the BAT trigger. The data
comprise 42 s in Windowed Timing (WT) mode (the first 7 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Osborne et
al. (GCN. Circ 12538).
The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=1.12 (+0.29, -0.27).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.15 (+0.12, -0.16). The
best-fitting absorption column is 3.5 (+6.0, -3.5) x 10^21 cm^-2, at a
redshift of 2.893, in addition to the Galactic value of 8.9 x 10^20
cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed)
0.3-10 keV flux conversion factor deduced from this spectrum is 3.3 x
10^-11 (4.5 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Galactic foreground: 8.9 x 10^20 cm^-2
Intrinsic column: 3.5 (+6.0, -3.5) x 10^21 cm^-2 at z=2.893
Photon index: 2.15 (+0.12, -0.16)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00507185.
This circular is an official product of the Swift-XRT team.
GCN Circular 12544
Subject
Continued Skynet observations of GRB111107A
Date
2011-11-07T22:21:48Z (14 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@email.unc.edu>
A. LaCluyze, J. Haislip, K. Ivarsen, D. Reichart, M. Nysewander, J. Moore,
A. Trotter, R. Egger, A. Foster, A. Oza, T. Cromartie, E. Speckhard, and J.
A. Crain report:
Skynet continued observing the field of GRB 111107A (Swift trigger 507185,
Siegel et al., GCN 12534; LaCluyze et al., GCN 12535; Kruehler et al., GCN
12536; Kuin et al., GCN 12540) with the PROMPT telescopes located at CTIO
in Chile in B, R, and I. We detect the fading optical counterpart in R and
I, with limits in B. The fading is consistent with a power-law index of
~-0.7.
Preliminary light curve can be found at the following link:
http://skynet.unc.edu/grb/grb111107a.png
Prompt4, R-band, calibrated to 12 USNO B1.0 stars
T(mean) Tmean(days) Exps Mag 1-sig MagErr
14.75 m 0.01024 5 x 80 s 19.467 +0.427/-0.311
30.93 m 0.02148 13 x 80 s 19.883 +0.360/-0.273
61.87 m 0.04296 24 x 80 s 20.319 +0.337/-0.259
118.57 m 0.08234 43 x 80 s 20.818 +0.404/-0.298
3.815 h 0.15895 94 x 80 s 21.206 +0.243/-0.200
6.619 h 0.27579 102 x 80 s 21.837 +0.357/-0.271
Prompt5, I-band, calibrated to 15 USNO B1.0 stars
T(mean) Tmean(days) Exps Mag 1-sig MagErr
15.22 m 0.01057 4 x 80 s 18.443 +0.274/-0.220
24.77 m 0.01720 5 x 80 s 18.520 +0.263/-0.212
49.60 m 0.03444 24 x 80 s 19.474 +0.262/-0.212
112.45 m 0.07809 49 x 80 s 19.898 +0.300/-0.237
3.139 h 0.13081 43 x 80 s 20.297 +0.390/-0.291
6.189 h 0.25788 130 x 80 s 20.650 +0.273/-0.220
Prompt3, B-band, calibrated to 14 USNO B1.0 stars
T(mean) Tmean(days) Exps 3-SigLimMag
88.62 m 0.06154 47 x 80 s 20.3
4.738 h 0.19743 159 x 80 s 21.6
Further observations are planned. This message may be cited.
GCN Circular 12545
Subject
GRB 111107A: Fermi GBM observation
Date
2011-11-08T21:37:43Z (14 years ago)
From
Veronique Pelassa at UAH <vero.pelassa@gmail.com>
V. Pelassa (UAH) reports on behalf of the Fermi GBM Team:
"At 00:50:25.48 UT on 07 November 2011, the Fermi Gamma-Ray Burst
Monitor triggered and located GRB 111107A (trigger 342319827 /
111107035) which was also detected by the Swift/BAT (Siegel et al.
2011, GCN 12534). The GBM on-ground location is consistent with the
Swift position. The angle from the Fermi LAT boresight is 119 degrees.
The GBM light curve consists of a FRED-like pulse with a duration
(T90) of about 12 s (50-300 keV). The time-averaged spectrum from
T0-1.024 s to T0+11.264 s is well fit by a power law function with an
exponential high-energy cutoff. The power law index is -1.38 +/- 0.21
and the cutoff energy, parameterized as Epeak, is 108 +/- 32 keV
(Castor statistics 318.55 for 365 d.o.f.).
The event fluence (10-1000 keV) in this time interval is
(1.392 +/- 0.197)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.96 s in the 10-1000 keV band is
2.6 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 12558
Subject
GRB111107A: ATCA observations - upper limit and a possible detection
Date
2011-11-17T09:28:48Z (14 years ago)
From
Paul Hancock at U of Sydney <hancock@physics.usyd.edu.au>
Paul J. Hancock, Tara Murphy (U of Sydney)
We observed GRB111107A (GCN12534) with the Australian Telescope
Compact Array (ATCA) on Nov 07 at 12 UT (~11 hours after the GRB
trigger). At 9GHz there is no sign of any emission from the GRB above
a 3� limit of 200uJy. At 5.5GHz there appears to be a 4� source at
300+/-40uJy at the UVOT location of the GRB (GCN 12538). In both cases
the measurement of the possible GRB flux is complicated by the
presence of one or more confusing radio sources in the field of view.
Further observations are planned. We thank the observatory staff for
scheduling and supporting these observations.
GCN Circular 12564
Subject
GRB111107A: Further ATCA observations - no detection
Date
2011-11-18T00:25:22Z (14 years ago)
From
Paul Hancock at U of Sydney <hancock@physics.usyd.edu.au>
Paul J. Hancock, Tara Murphy (U of Sydney)
Following the possible detection reported in GCN12558 we again
observed GRB111107A (GCN12534) with the Australian Telescope Compact
Array (ATCA) on Nov 14 from 16:54UT to 18:43UT (~7.5 days after the
GRB trigger). We detect no emission from the GRB with a 3sigma limit
of 180 uJy and 150 uJy at 5.5GHz and 9 GHz respectively. Given that
the 5.5 GHz radio luminosity of the GRB is expected to increase over
at least the first 7.5 days post burst, we conclude that the possible
4sigma detection reported in GCN12558 is a result of the nearby source
SUMSS J083735-663107. No further observations are planned. We thank
the observatory staff for scheduling and supporting these
observations.