GRB 111117A
GCN Circular 12625
Subject
GRB 111117A: Refined GMG observation
Date
2011-12-07T12:48:44Z (14 years ago)
From
Dong Xu at Weizmann Inst <dong.dark@gmail.com>
D. Xu (WIS) reports on behalf of a larger collaboration:
We re-processed 1x600s R-band and 3x600s z-band images (Zhao et al.,
GCN 12560), starting 1.960 hrs post-burst, with calibration frames
available later on. The R-band non-detection remains unchanged.
However, in the stacked z-band image an optical source was weakly
detected, with its position consistent with the NOT position (Andersen
et al., GCN 12563), the refined XRT position (Melandri et al., GCN
12565), as well as the refined Chandra position (Berger et al., GCN
12588), and to the magnitude of z=22.9+/-0.3, calibrated with nearby
SDSS stars. The z-band afterglow faded and was not detected by
following GROND observation (Schmidl et al., GCN 12568).
GCN Circular 12588
Subject
GRB 111117A: Refined Chandra Astrometry
Date
2011-11-23T20:58:42Z (14 years ago)
From
Edo Berger at Harvard <eberger@cfa.harvard.edu>
E. Berger, W. Fong (Harvard), T. Sakamoto (GSFC/UMBC), and E. Troja
(NASA/GSFC/ORAU) report:
"We re-analyzed the Chandra observation of the short GRB 111117A (Sakamoto
et al. GCN 12580) for the purpose of clarifying and refining the astrometry
relative to the location of the host galaxy (using an optical image from
Magellan/IMACS: Fong et al. GCN 12566). Using 4 objects in common to the
Chandra data and the IMACS image (which is itself tied to USNO-B with 0.25"
rms) we find a correction to the native Chandra astrometry of:
dRA = -0.54+/-0.17"
dDEC = +0.34+/-0.14"
substantially improved relative to the 0.6" systematic uncertainty of the
native Chandra astrometry (Sakamoto et al. GCN 12580). With this
correction, the position of the X-ray counterpart of GRB 111117A is (J2000):
RA = 00:50:46.257
DEC = +23:00:40.01
with a statistical uncertainty of about 0.13" in each coordinate.
Relative astrometry compared to the centroid of the host galaxy indicates a
projected angular offset of 1.0". Although the redshift of the host galaxy
is not known at the present, this roughly corresponds to 6-8 kpc at
redshifts of z>0.5 (typical of short GRB offsets: Fong et al. 2010, ApJ,
708, 9)."
GCN Circular 12586
Subject
GRB 111117A, the review of the sky area in plate archives
Date
2011-11-23T14:21:21Z (14 years ago)
From
Valentyna Golovnya at Main Astro Obs,Kyiv <golov_v@ukr.ne>
V.V. Golovnya, L.M. Kizyun (Main Astro Obs, Kyiv) report:
We have undertaken the review of the sky area of GRB 111117A
(W. Fong et al. GCN Circ.12566) on astronegatives, collected
in Ukrainian NAS Main astronomical observatory plate archive
(1976-1996). All the plates with the possible object
appearance are digitized using Microtek ScanMaker 9800XL TMA
flatbed scanner and have been placed into Golosiiv Plate
Archive database DBGPA with open access to them.
The list of plates is given in the table:
YYYYMMDD TimeUT --Plates-- Exp. LimMag USNOA2
19860910 231743 GUA040C001009 16.0 15.20 1125-00304111
19860927 221901 GUA040C001012B 14.0 15.20 1125-00304111
19870917 230117 GUA040C001118A 16.0 15.20 1125-00304111
19880821 010032 GUA040C001325A 16.0 13.70 1125-00304597
19911009 205736 GUA040C001853A 15.5 15.20 1125-00304111
Plates-the plate's identifier in GUA040C archives
of DWA (D/F=400/2000, M=103"/mm) of the Ukrainian NAS
Main Astro obs in Kyiv (Marsden's number - 83)[1].
Exp. - Duration of the maximum exposure (minutes).
LimMag - Limited V mag, derived in the 10 minutes area around
the location given in W. Fong et al. GCN Circ.12566:
RA(J2000): 00h 50m 46.24s, Dec(J2000): +23d 00' 41.04"
USNOA2 - Comparison star.
The preview images of 11 areas together with
the 10x10 min.of arc area from SkyMap can be found in
http://gua.db.ukr-vo.org/img/grb/111117A/index.html
The images with full resolution are available via e-mail on
demand.
References:
1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0),
http://gua.db.ukr-vo.org
GCN Circular 12580
Subject
GRB 111117A: Chandra detection of the afterglow
Date
2011-11-21T21:40:47Z (14 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
T. Sakamoto (GSFC/UMBC), E. Troja (NASA/GSFC/ORAU), N. Gehrels (GSFC),
J. Norris (BSU), S. D. Barthelmy (GSFC), J. L. Racusin (GSFC),
N. Kawai (Tokyo Tech), A. Fruchter (STScI)
A Chandra ToO observation of GRB 111117A (Mangano et al., GCN Circ. 12559;
Sakamoto et al., GCN Circ. 12561) started on November 20 12:39 UT (~3 days
after the GRB trigger) for a total of 19.8 ksec. The X-ray afterglow of the
burst in the 0.3-8 keV band was detected at a position RA, Dec 12.69286, +23.01108
which is equivalent to:
RA (J2000) = 00 50 46.29
Dec(J2000) = 23 00 39.9
The 1-sigma statistical error is 0.09 and 0.15 arcsec on RA and Dec respectively.
The systematic error of the Chandra aspect solution is 0.6 arcsec (radius, 90%
containment; i.e, http://cxc.harvard.edu/cal/ASPECT/celmon/) which dominates
the localization uncertainty. The detection significance is 3.9 sigma (7.8 net source
counts and 0.2 estimated background counts) by the ciao wavdetect software.
The Chandra location is consistent with the enhanced XRT error circle (Melandri et al.,
GCN Circ. 12565) and the reported optical afterglow/host galaxy candidate from the NOT
observation (Andersen et al., GCN Circ. 12563). However, we note that the optical
candidate reported from the Magellan observation (Fong et al., GCN Circ 12566) is
offset by 1.3 arcsec from the Chandra location.
We would like to thank Harvey Tananbaum and the Chandra operation team for rapidly
approving and making this observation.
GCN Circular 12577
Subject
GRB 111117A: Gemini Afterglow Limits
Date
2011-11-21T10:02:31Z (14 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (UC Berkeley) and A. Cucchiara (UC Santa Cruz / UCO Lick)
report on behalf of a larger collaboration:
We obtained a second epoch of imaging of the X-ray afterglow error circle
of the short-hard GRB111117A (Mangano et al., GCN 12559) with the Gemini
Multi-Object Spectrograph mounted on the 8-m Gemini South telescope.
Observations were taken in the r' filter beginning at 1:18 UT on 2011 Nov
20 (~ 2.5 days after the Swift trigger).
The host galaxy candidate (Andersen et al., GCN 12563; Fong et al., GCN
12566) is well detected in our stacked image, and has maintained a
constant brightness (within uncertainties) when compared with our first
epoch of GMOS imaging (Cucchiara et al., GCN 12567). Using the HOTPANTS
image subtraction software package, we have differenced the two images and
estimate a limit on the afterglow flux of r' > 25.5 mag at our first epoch
(calculated with respect to several SDSS stars in the field).
GCN Circular 12576
Subject
GRB 111117A: optical upper limit in CrAO
Date
2011-11-20T15:51:37Z (14 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev, N. Pit (CrAO), A. Pozanenko (IKI) report on behalf of larger
GRB follow-up collaboration:
We observed field of the Swift GRB 111117A (Mangano et al. GCN 12559)
with AZT-11 telescope of CrAO in R filter between Nov. 17 (UT) 16:11:05 -
17:14:24, i.e. starting ~ 4 h after burst trigger. We took several images of
180 exposure under variable weather conditions and mean seeing (FWHM) of
about 2.7". We do not detect any source within XRT position (Melandri et
al. GCN 12565). A photometry is based on the USNO B1.0 1130-0013895 star
(00:50:46.48 +23:01:28.8) assuming R=16.98:
T0+ Filter, Exposure, OT, UpperLimit
(mid, d) (s)
0.1879 R 22x180 n/d 20.6
GCN Circular 12573
Subject
GRB 111117A: Fermi GBM observation
Date
2011-11-19T15:35:22Z (14 years ago)
From
Suzanne Foley at MPE <sfoley@mpe.mpg.de>
S. Foley (MPE) and P. Jenke (UAH)
report on behalf of the Fermi GBM Team:
"At 12:13:42.03 UT on 17 November 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 111117A (trigger 343224824 / 111117510)
which was also detected by the Swift/BAT
(Mangano et al. 2011, GCN 12559).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 12 degrees.
Moreover, this burst was bright enough to result in a Fermi spacecraft
autonomous rapid repoint (ARR) maneuver.
The GBM light curve consists of two pulses
with a duration (T90) of about 0.5 s (50-300 keV).
The time-averaged spectrum from T0-0.128 s to T0+0.384 s is
well fit by a power law function with an exponential high-energy cutoff.
The power law index is -0.69 (+0.17/- 0.15) and the lower limit on
the cutoff energy, parameterized as Epeak, is 370 keV.
The event fluence (10-1000 keV) in this time interval is
(6.7 +/- 0.2)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.128 s in the 10-1000 keV band
is 2.8 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 12572
Subject
GRB 111117A: further NOT observations
Date
2011-11-19T10:35:25Z (14 years ago)
From
Giorgos Leloudas at Dark Cosmology Centre <giorgos@dark-cosmology.dk>
Giorgos Leloudas, Daniele Malesani (DARK) and Dong Xu (WIS) report on behalf of a larger collaboration:
We have continued observing GRB 111117A (Mangano et al., GCN 12559) using ALFOSC on the Nordic Optical Telescope (NOT).
In addition, we have made a more careful analysis of the data reported in Andersen et al. (GCN 12563).
Our R-band photometry, calibrated to USNO B1, can be summarized in the following table:
Stack mid-time R
5x300 s 7.93 hr 23.36+-0.15
5x300 s 9.88 hr 23.98+-0.24
8x300 s 36.38 hr 23.74+-0.20
If we instead stack all the images obtained during the first night (10x300s, mid-time 8.91 hr after the GRB), we obtain R = 23.81+-0.17.
Based on the NOT observations only, we suggest that there is some evidence of fading (albeit at low significance) between the observations obtained at 7.93 hr and later, indicating that at that time there was some contribution from the GRB afterglow to the underlying host galaxy light.
We are grateful to the NOT observers, Kristian Vida (Konkoly Observatory) and
Heidi Korhonen (U. Copenhagen) for obtaining these observations.
GCN Circular 12571
Subject
GRB 111117A: EVLA observations
Date
2011-11-19T01:10:01Z (14 years ago)
From
Wen-fai Fong at CFA <wfong@cfa.harvard.edu>
W. Fong, B. A. Zauderer and E. Berger (Harvard) report:
"We observed the position of the short GRB 111117A (GCN 12559) with the
EVLA beginning 2011 November 18.0 UT (11.8 hours post-burst) at a mean
frequency of 5.8 GHz. In two hours of observations, we do not detect any
radio source within the enhanced XRT position (GCN 12565) down to a 3-sigma
limit of ~34 microJy."
GCN Circular 12570
Subject
GRB 111117A: TNG observations
Date
2011-11-18T11:32:21Z (14 years ago)
From
Andrea Melandri at INAF-OAB <andrea.melandri@brera.inaf.it>
A. Melandri, D. Fugazza, S. Covino (INAF-OAB) and E. Palazzi (INAF-
IASFBo)
on behalf of a larger collaboration report:
We observed the field of GRB 111117A (Mangano et al. GCN 12559) with
the 3.6m TNG equipped with the Dolores camera. A sequence of 6x300s
images were acquired starting on Nov 17.801 UT (i.e. ~7 hours after
the burst event).
No obvious fading object is detected inside the refined XRT error
circle (Melandri et al. GCN 12565), while the extended object
previously reported by Andersen et al. (GCN 12563), Fong et al. (GCN
12566), Cucchiara et al. (GCN 12567) and Schmidl et al. (GCN 12568) is
clearly visible in our coadded image.
Calibrating against a set of USNO-B1 stars of the field we find R =
23.1 +/- 0.2, consistent with the value found by Andersen et al. (GCN
12563). We caution about the possible fading of this object, as
reported by Fong et al. (GCN 12566), because the apparent difference
of magnitude could be related to the different calibration system.
Since this object is extended also in our image and it does not seem
to vary, it is more likely the host galaxy of GRB 111117A.
We thank the TNG staff for their support, in particular Aldo Fiorenzano.
GCN Circular 12569
Subject
GRB 111117A: Swift/UVOT Upper Limits
Date
2011-11-18T11:04:27Z (14 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (MSSL-UCL) and V. Mangano (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 111117A
137 s after the BAT trigger (Mangano et al., GCN Circ. 12559).
No optical afterglow consistent with the XRT position
(Melandri et al., GCN Circ. 12565) or the optical position
(Andersen et al., GCN Circ. 12563 & Fong et al., GCN Circ. 12566) is
detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u_FC 137 387 246 >20.4
v 443 1241 97 >19.3
b 392 1191 117 >20.0
u 137 1315 490 >20.7
w1 493 1290 97 >20.4
m2 468 1117 78 >19.5
w2 419 1217 97 >21.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 12568
Subject
GRB 111117A: GROND observations
Date
2011-11-18T11:02:44Z (14 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
S. Schmidl, A. Rossi, D. A. Kann, (all TLS Tautenburg) and J. Greiner (MPE
Garching) report on behalf of the GROND team:
We observed the field of GRB 111117A (Swift trigger #507901, Mangano et al.,
GCN 12559) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla
Observatory (Chile).
Observations started at 02:01 UT on November 18, 13.8 hr after the GRB
trigger. They were performed at an average seeing of 1".8 and an average
airmass of 1.7 .
We detect the afterglow/host candidate that was reported by Andersen et
al. (GCN 12563, R = 23.1 � 0.3), Fong et al. (GCN 12566, r = 23.9 � 0.15)
and Cucchiara et al. (GCN 12567, r' = 23.99 � 0.11) in the g' and r' band.
Based on the first 75 min of total exposures in g'r'i'z' and 60 min in
JHK, we estimate preliminary magnitudes (all in AB system) of
g' = 24.08 � 0.15,
r' = 24.08 � 0.16,
i' > 23.9,
z' > 23.4,
J > 21.7,
H > 21.3 and
K > 19.5.
Our r'-band magnitude is in agreement with Fong et al. and Cucchiara et al.
Magnitudes are calibrated against SDSS as well as 2MASS field stars
and are not corrected for the expected Galactic foreground extinction
corresponding to a reddening of E_(B-V)=0.03 mag in the direction of the
burst (Schlegel et al. 1998).
GCN Circular 12567
Subject
GRB 111117A: Gemini host observation
Date
2011-11-18T05:36:11Z (14 years ago)
From
Antonino Cucchiara at LBNL <acucchiara@lbl.gov>
A. Cucchiara (UCSC/UCO Lick) and S. B. Cenko (UC Berkeley) report
on behalf of a large collaboration:
On November 18.07 UT we observed the field of the short-hard
GRB 111117A (Mangano et al., GCN 12559) with the Gemini-South
telescope equipped with the GMOS instrument.
In our 30 minutes co-added image in r' band we clearly detect the
source identified by Andersen et al. and Fong et al.(GCN 12563,
12566): this object appear to be elongated in the SW-NE direction,
suggesting it is indeed the host of GRB 111117A.
Using several SDSS (DR8) objects in the field we obtain a value of
r' = 23.99 +/- 0.11 for this galaxy brightness, consistent
with the one reported by the Magellan Telescope.
We thank the Gemini-South staff for performing these observations,
in particular Pascale Hibon.
GCN Circular 12566
Subject
GRB111117A: Magellan IMACS observations
Date
2011-11-18T04:35:38Z (14 years ago)
From
Wen-fai Fong at CFA <wfong@cfa.harvard.edu>
W. Fong, N. Sanders, D. Milisavljevic and E. Berger (Harvard) report:
We imaged the location of the short GRB 111117A (GCN 12559) with IMACS on
the Magellan/Baade 6.5-m telescope starting on 2011 November 18.07 UT (13.5
hrs post-burst) in 1.0" seeing. In a stack of 4x300 sec r-band exposures,
we detect an extended source at the edge of the enhanced XRT error circle
(GCN 12565) at a position of:
RA = 00:50:46.24
Dec = +23:00:41.04
(J2000)
with an uncertainty of ~0.5" in each coordinate. This is consistent with
the source position reported by Andersen et al. (GCN 12563, R = 23.1 +/-
0.3).
We calculate the extended source to have a magnitude of r = 23.9 +/- 0.15.
The fainter magnitude implies that the source reported by Andersen et al.
has faded between 7.9 and 13.5 hours post-burst.
GCN Circular 12565
Subject
GRB 111117A: Swift-XRT refined Analysis
Date
2011-11-18T01:27:07Z (14 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/IASFPA), G. Stratta
(ASDC), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), O.M. Littlejohns
(U. Leicester) and V. Mangano report on behalf of the Swift-XRT team:
We have analysed 7.0 ks of XRT data for GRB 111117A (Mangano et al.
GCN Circ. 12559), from 89 s to 30.1 ks after the BAT trigger. The data
comprise 18 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The best available XRT position (using the
promptly downlinked event data, the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 12.6926,
23.0109 which is equivalent to:
RA (J2000): 00 50 46.22
Dec(J2000): +23 00 39.2
with an uncertainty of 2.1 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.33 (+0.14, -0.13).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+/-0.4). The
best-fitting absorption column is 2.2 (+1.1, -1.0) x 10^21 cm^-2, in
excess of the Galactic value of 3.7 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 3.5 x 10^-11 (5.8 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.2 (+1.1, -1.0) x 10^21 cm^-2
Galactic foreground: 3.7 x 10^20 cm^-2
Excess significance: 3.4 sigma
Photon index: 2.2 (+/-0.4)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00507901.
This circular is an official product of the Swift-XRT team.
GCN Circular 12563
Subject
GRB 111117A: NOT observations
Date
2011-11-17T22:57:59Z (14 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
Michael I. Andersen (DARK), Antonio de Ugarte Postigo (IAA-CSIC and DARK),
Giorgos Leloudas (DARK), Johan P. U. Fynbo (DARK) report on behalf of a
larger collaboration:
Using ALFOSC on the Nordic Optical Telescope (NOT) we have obtained R-band
(6 x 300 s) imaging of the field of the Swift GRB 111117A (Mangano et
al., GCN 12559), starting on 2011 November 20:49:50 UT (mean epoch 7.88
hours after the burst trigger). The seeing during the observations was
around 0.9".
In a preliminary reduction we detect a source with a magnitude of R=23.1 +/- 0.3
(based on USNO-B1.0 photometry) at the coordinates (J2000.0 +/- 1"):
R.A.: 00:50:46.28
Dec.: +23:00:40.3
This is formally 3.6" from the XRT position and thus outside the
XRTerror circle reported in GCN 12559. However we note that it is
within the automatically generated SPER error box
(http://www.swift.ac.uk/sper/507901/).
We therefore suggest that this object is the host galaxy or afterglow of
GRB 111117A.
We are grateful to the NOT observers, Kristian Vida (Konkoly Observatory) and
Heidi Korhonen (U. Copenhagen) for obtaining these observations.
GCN Circular 12562
Subject
GRB 111117A: Chandra ToO observation scheduled
Date
2011-11-17T21:07:23Z (14 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
T. Sakamoto (GSFC/UMBC), N. Gehrels (GSFC), E. Troja (NASA/GSFC/ORAU),
J. Norris (BSU), S. D. Barthelmy (GSFC), J. L. Racusin (GSFC),
N. Kawai (Tokyo Tech), A. Fruchter (STScI)
The Chandra ToO observation has been approved for GRB 111117A
(Mangano et al., GCN Circ. 12559; Sakamoto et al., GCN Circ. 12561).
The observation has been tentatively scheduled on November 20 12:48 UT
for 20 ksec.
This is the approved ToO program in AO-13 to identify a Swift short GRB
afterglow in X-rays by a sub-arcsecond position from Chandra
(PI: Sakamoto, #501616). The main goal is to identify the host galaxy
of GRB 111117A by the sub-arcsecond X-ray position which is very likely
to be able to obtain from the Chandra observation. Therefore, we strongly
encourage deep optical observations of the field.
GCN Circular 12561
Subject
GRB 111117A: Swift-BAT refined analysis of a short hard burst
Date
2011-11-17T20:12:02Z (14 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), V. Mangano (INAF-IASFPA),
J. Norris (BSU), D. M. Palmer (LANL), G. Sato (ISAS), 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+395 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 111117A (trigger #507901)
(Mangano, et al., GCN Circ. 12559). The BAT ground-calculated position is
RA, Dec = 12.702, 23.021 deg, which is
RA(J2000) = 00h 50m 49.9s
Dec(J2000) = +23d 00' 11.0"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows two peaks, the first starts at ~T+0.00,
peaks at ~T+0.15 and ends at ~T+0.30 sec. The second starts at ~T+0.35,
peaks at ~T+0.50, and ends at ~T+0.60 sec. T90 (15-350 keV) is 0.47 +- 0.09 sec
(estimated error including systematics).
The spectral lag is 0.6 +/- 2.4 msec using the 100-350 and 25-50 keV bands
with 4-ms binning of the raw lightcurves. This clearly indicates a short burst.
The time-averaged spectrum from T-0.016 to T+0.520 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
0.65 +- 0.22. The fluence in the 15-150 keV band is 1.40 +- 0.18 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.00 sec in the 15-150 keV band
is 1.35 +- 0.20 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/507901/BA/
[GCN OPS NOTE(17nov11): Per author's request, the missing position uncertainty
was added (1.7 arcmin).]
GCN Circular 12560
Subject
GRB 111117A: GMG upper limit
Date
2011-11-17T16:54:52Z (14 years ago)
From
Dong Xu at Weizmann Inst <dong.dark@gmail.com>
X.-H. Zhao (YNAO), D. Xu (WIS), J.-R. Mao, J.-M. Bai (YNAO) report:
We observed the field of GRB 111117A (Mangano et al., GCN 12559) at
the 2.4m Gao-Mei-Gu telescope (GMG) equipped with YFOSC. The weather
was not optimistic but 1x600s R-band and 3x600s z-band images were
obtained, starting at 14:11:16 UT, 17 Nov. 2011 (i..e, 1.960 hrs after
the burst). No afterglow was detected within the XRT error circle for
both filters, to a 3sigma upper limit of R~22.2 mag, calibrated with
the USNO B1 catalog.
We thank Gui-Hua He, Jian-Quan He, and Yu-Xin Xin for performing these
observations.
GCN Circular 12559
Subject
GRB 111117A: Swift detection of a short hard burst
Date
2011-11-17T12:27:17Z (14 years ago)
From
David Burrows at PSU/Swift <burrows@astro.psu.edu>
V. Mangano (INAF-IASFPA), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),
O. M. Littlejohns (U Leicester), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), S. R. Oates (UCL-MSSL),
C. Pagani (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), E. Sonbas (GSFC/USRA/Adiyaman Univ.),
R. L. C. Starling (U Leicester), C. A. Swenson (PSU) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:
At 12:13:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111117A (trigger=507901). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 12.702, +23.021 which is
RA(J2000) = 00h 50m 49s
Dec(J2000) = +23d 01' 16"
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 0.6 sec. The peak count rate
was ~6140 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 12:14:58.7 UT, 76.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 12.6925, 23.0103 which
is equivalent to:
RA(J2000) = 00h 50m 46.19s
Dec(J2000) = +23d 00' 36.9"
with an uncertainty of 2.6 arcseconds (radius, 90% containment). This
location is 50 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. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.70 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 3
(+2.73/-2.30) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 250 seconds with the U filter starting
136 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 100% of the
XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The
8'x8' region for the list of sources generated on-board covers 100% of the XRT
error circle. The list of sources is typically complete to about 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.03.
Burst Advocate for this burst is V. Mangano (vanessa AT ifc.inaf.it).
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.)