GRB 111123A
GCN Circular 12587
Subject
GRB 111123A: Swift detection of a burst
Date
2011-11-23T18:33:53Z (14 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), M. M. Chester (PSU), V. D'Elia (ASDC),
N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), A. Y. Lien (NASA/GSFC/ORAU),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
P. T. O'Brien (U Leicester), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), T. Sakamoto (NASA/UMBC),
C. J. Saxton (UCL-MSSL), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), R. L. C. Starling (U Leicester),
G. Stratta (ASDC), G. Tagliaferri (INAF-OAB),
E. Troja (NASA/GSFC/ORAU), T. N. Ukwatta (MSU) and B.-B. Zhang (PSU)
report on behalf of the Swift Team:
At 18:13:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111123A (trigger=508319). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 154.851, -20.642 which is
RA(J2000) = 10h 19m 24s
Dec(J2000) = -20d 38' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a few overlapping peaks
from T-10 to T+30 sec and then a strong peak from T+60 to T+160 sec,
with a total duration of about 170 sec. The peak count rate was ~1400 counts/sec
(15-350 keV), at ~3 sec after the trigger.
The XRT began observing the field at 18:15:00.5 UT, 99.4 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 154.8464,
-20.6453 which is equivalent to:
RA(J2000) = 10h 19m 23.14s
Dec(J2000) = -20d 38' 43.1"
with an uncertainty of 3.3 arcseconds (radius, 90% containment). This
location is 20 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. The XRT
light curve shows correlated activity with BAT, rising to peak followed
by fading.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.78
x 10^20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 8.48e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 109 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 19.6 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 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.05.
Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT 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 12589
Subject
GRB 111123A: GMG optical observation
Date
2011-11-24T02:23:25Z (14 years ago)
From
Dong Xu at Weizmann Inst <dong.dark@gmail.com>
D. Xu (WIS), X.-H. Zhao, J.-R. Mao, J.-M. Bai (YNAO) report:
We observed the field of GRB 111123A (Stamatikos et al., GCN 12587)
with the 2.4m Gao-Mei-Gu (GMG) telescope equipped with YFOSC, and
obtained 3x600s R-band and 3x600s I-band images, starting at 21:00:56
UT on Nov. 23rd (i.e., 2.793 hrs after the burst).
Within the XRT SPER error circle (http://www.swift.ac.uk/sper/), no
optical source was detected in the stacked I-band image, and a weak
and compact source was found in the stacked R-band image at
coordinates
RA(J2000) = 10:19:23.10
Dec(J2000) = -20:38:41.72
with an uncertainty of ~1" in each coordinate. We caution that the
above source may be ascribed to background fluctuation. In this sense,
we derive R>~23.7 mag, calibrated with the #0693-0243590 star
(R1=17.95 and R2=17.60) in the USNO B1 catalog.
Deeper and NIR observations are encouraged.
We are grateful to Chuan-Jun Wang, De-Qing Wang, and Yan-Dong Lang for
performing these observations.
[GCN OPS NOTE(24nov11): Per author's request, Mao was added to the author list.]
GCN Circular 12590
Subject
GRB 111123A: Enhanced Swift-XRT position
Date
2011-11-24T05:02:34Z (14 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.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 2720 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 111123A, 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 = 154.84638, -20.64469 which is equivalent
to:
RA (J2000): 10h 19m 23.13s
Dec (J2000): -20d 38' 40.9"
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 12591
Subject
GRB 111123A: MITSuME Okayama Optical upper limits
Date
2011-11-24T05:49:35Z (14 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 111123A (Stamatikos et al., GCNC 12587)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2011-11-23 18:30:27 UT (~17 min after
the burst). We did not find any new point source within the enhanced
XRT circle (Goad, et al., GCNC 12590) in all the three bands.
Three sigma upper limits of the OT are listed below. We used
GSC2.3 catalog for flux calibration.
T0+[day] MID-UT T-EXP[sec] g' Rc Ic
------------------------------------------------------
0.01541 18:35:32 540.0 >18.9 >18.9 >18.3
0.04573 19:19:12 5820.0 >20.4 >20.2 >19.6
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 12592
Subject
GRB 111123A: Swift-XRT refined Analysis
Date
2011-11-24T09:34:05Z (14 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
G. Stratta (ASDC), D.N. Burrows (PSU), J.A. Kennea (PSU), M.C. Stroh
(PSU), O.M. Littlejohns (U. Leicester), J.P. Osborne (U. Leicester),
K.L. Page (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and
M. Stamatikos report on behalf of the Swift-XRT team:
We have analysed 11 ks of XRT data for GRB 111123A (Stamatikos et al.
GCN Circ. 12587), from 88 s to 35.6 ks after the BAT trigger. The data
comprise 656 s in Windowed Timing (WT) mode (the first 9 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 Goad et al.
(GCN. Circ 12590).
The late-time light curve (from T0+4.2 ks) can be modelled with a
power-law decay with a decay index of alpha=0.86 (+/-0.10).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.715 (+/-0.026). The
best-fitting absorption column is 2.62 (+0.10, -0.09) x 10^21 cm^-2,
in excess of the Galactic value of 5.8 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.43 (+0.19, -0.18)
and a best-fitting absorption column of 2.0 (+/-0.4) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.1 x 10^-11 (5.8 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.0 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 5.8 x 10^20 cm^-2
Excess significance: 7.4 sigma
Photon index: 2.43 (+0.19, -0.18)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00508319.
This circular is an official product of the Swift-XRT team.
GCN Circular 12593
Subject
GRB 111123A: TNG NIR detection of the afterglow candidate
Date
2011-11-24T12:33:57Z (14 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
D. Fugazza (INAF-OAB), V. D'Elia (INAF-OAR), P. D'Avanzo, A. Melandri
(INAF-OAB) and E. Palazzi (INAF-IASFBo) on behalf of a larger
collaboration report:
We observed the field of GRB 111123A (Stamatikos et al. GCN 12587) with
the 3.6m TNG equipped with the NICS near-infrared camera. A sequence of
JHK band images were acquired starting on Nov 24.238 UT (i.e. ~11.5 hours
after the burst event).
An object is detected in a stacked 20 min exposure image inside the
enhaced XRT error circle (Goad et al. GCN 12590) at the following
coordinates (J2000):
R.A. = 10:19:23.14
Dec. = -20:38:41.0
with an uncertainty of ~ 0.3", consistent with the position of the object
reported by Xu et al. (GCN 12589). The source has a magnitude K=19.4 +/-
0.3 (calibrated against the 2MASS catalogue). The source is not detected
in the shorter exposures (10 min) J and H-band images down to the
following 3sigma upper limits: J>19.7, H>20.5. At the present stage, it is
not possible to say anything about source variability.
We thank the TNG staff for their support, in particular Luca Di Fabrizio.
GCN Circular 12594
Subject
GRB 111123A: correction to GCN 12593
Date
2011-11-24T13:58:56Z (14 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo (INAF-OAB) on behalf of a larger collaboration report:
The TNG NIR 3sigma upper limits of GRB 111123A reported in Fugazza et al.
(GCN 12593) has been written in the wrong order. The correct values are:
J>20.5
H>19.7
(calibrated against the 2MASS catalogue). We confirm the K-band detection.
We apologize for the confusion that our previous report may have caused.
GCN Circular 12595
Subject
GRB 111123A, GROND observations
Date
2011-11-24T16:04:07Z (14 years ago)
From
Ana Nicuesa at TLS Tautenburg <ana@tls-tautenburg.de>
A. Rossi, A. Nicuesa Guelbenzu, S. Klose (all Tautenburg), P. Afonso
(American River College), and J. Greiner (MPE) report on behalf of the
GROND team:
We observed the field of GRB 111123A (Stamatikos, GCN 12587)
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 on La Silla. Observations
started at 6:30 UT on November 24, about 12 hr after the burst, and
continued for about 1.5 hr. They were performed at an average seeing of 1
arcsec and an average airmass of 1.5.
We do not detect the source discovered by Xu et al. (GCN 12589; see
also Fugazza et al. GCN 12593). At a mean time of November 24, 7:10 UT,
we measure the following preliminary upper limits (AB magnitudes):
g' > 24.5,
r' > 24.6,
i' > 23.7,
J > 21.2,
H > 20.9,
K > 19.9.
The data are calibrated against GROND zeropoints and 2MASS field stars.
GCN Circular 12596
Subject
GRB 111123A - NOT optical observations
Date
2011-11-24T17:38:19Z (14 years ago)
From
Annalisa De Cia at U of Iceland <annalisa@raunvis.hi.is>
A. De Cia (U. of Iceland), D. Xu (WIS), N.R. Tanvir (U. of Leicester), G. Leloudas, D. Malesani (DARK), G. Maciejewski (U. Nicolaus Copernicus), A. de Ugarte Postigo (IAA/CSIC), J.P.U. Fynbo (DARK) and P. Jakobsson (U. of Iceland) report:
We observed the field of GRB 111123A (Stamatikos et al., GCN 12587, Fugazza et al. 12593) with the NOT equipped with ALFOSC at the end of the night in La Palma, when the humidity dropped below the observability threshold. Observations were carried out in the R filter for 30 minutes, starting at 5:59 UT, with a mean time of 12.02 hours after the GRB trigger.
No significant source was detected at the position of the candidate optical afterglow (Xu et al., GCN 12589) down to R>~24.4 mag, calibrated against USNO-B1stars.
GCN Circular 12597
Subject
GRB 111123A: Swift/UVOT Upper Limits
Date
2011-11-24T20:37:04Z (14 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <Stephen.T.Holland@nasa.gov>
S. T. Holland (CRESST/USRA/GSFC) and M. Stamatikos (OSU/NASA/GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 111123A starting 90 s
after the BAT trigger (Stamatikos et al., 2011, GCNC 12587). Settled
observations started at 110 s. We do not detect an optical afterglow
at the location of the optical and near-infrared afterglow (Xu et al.,
2011, GCNC 12589; Fugazza et al., 2011, GCNC 12593) in any of the UVOT
filters. Preliminary 3-sigma upper limits for detecting a source in
the finding charts and in the co-added images, are
Filter TSTART TSTOP EXPOSURE Mag
---------------------------------------------------
white (FC) 110 260 147 >21.2
u (FC) 268 518 246 >20.3
white (FC) 871 934 62 >20.1
---------------------------------------------------
v 598 5999 430 >20.2
b 524 6711 325 >20.7
u 268 6614 678 >20.8
uvw1 647 6409 432 >20.6
uvm2 622 6204 432 >20.6
uvw2 573 5795 432 >20.9
white 110 5589 445 >21.7
---------------------------------------------------
The quoted magnitudes and upper limits have not been corrected
for the Galactic extinction along the line of sight to this burst of
E_{B-V} = 0.05 mag (Schlegel et al. 1998, ApJS, 500, 525).
GCN Circular 12598
Subject
GRB 111123A, Swift-BAT refined analysis
Date
2011-11-26T00:24:19Z (14 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
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+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 111123A (trigger #508319)
(Stamatikos, et al., GCN Circ. 12587). The BAT ground-calculated position is
RA, Dec = 154.845, -20.639 deg which is
RA(J2000) = 10h 19m 22.9s
Dec(J2000) = -20d 38' 19.9"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 81%.
The mask-weighted light curve shows two episodes. The first episode is starting
at T-10 sec, and peaking at T+10 sec with possible two or three overlapping pulses.
The second episode shows a gradual increases after the end of the initial episode,
peaks at T+150 sec, and ends at T+170 sec. The low level emission continues
up to T+~300 sec. T90 (15-350 keV) is 290.0 +- 88.1 sec (estimated error including
systematics).
The time-averaged spectrum from T-8.7 to T+481.3 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.68 +- 0.07. The fluence in the 15-150 keV band is 7.3 +- 0.3 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+146.30 sec in the 15-150 keV band
is 0.9 +- 0.1 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/508319/BA/
GCN Circular 12613
Subject
GRB 111123A: optical upper limit in CrAO
Date
2011-12-04T16:11:41Z (14 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
We observed the field of GRB 111123A (Stamatikos et al. GCN 12587) with
Shajn telescope of CrAO observatory on Nov. 25 between (UT) 02:48 and 03:44
under a mean seeing of 2.0 arsces and large airmass. We took several frames
with exposure of 60 s in I-band. Within enhanced Swift-XRT position (Goad et
al. GCN 12590) we do not detected the optical counterpart (Xu et al., GCN
12589; Fugazza et al., GCN 12593). A photometry is based on the USNO B1.0
star 0693-0243552 (10 19 20.57, -20 39 18.7, J2000) assuming I=16.85.
T_start UT T0+ Filter, Exposure, OT, uplim (3 sigma)
(mid, d) (s)
02:48:33 1.89584 I 49x60 n/d 22.2
GCN Circular 12615
Subject
GRB 111123A: optical upper limit in CrAO: correction to the GCN circ. 12613
Date
2011-12-04T16:57:12Z (14 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
The text of the GCN circular #12613 should be corrected as following. I
apologize for possible inconvenience.
V. Rumyantsev, (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:
We observed the field of GRB 111123A (Stamatikos et al. GCN 12587) with
Shajn telescope of CrAO observatory on Nov. 25 between (UT) 02:48 and 03:44
under a mean seeing of 2.0 arsces and large airmass. We took several frames
with exposure of 60 s in I-band. Within enhanced Swift-XRT position (Goad et
al. GCN 12590) we do not detected the optical counterpart (Xu et al., GCN
12589; Fugazza et al., GCN 12593). A photometry is based on the USNO B1.0
star 0693-0243552 (10 19 20.57, -20 39 18.7, J2000) assuming I=16.85.
T_start UT T0+ Filter, Exposure, OT, uplim (3 sigma)
(mid, d) (s)
02:48:33 1.89584 I 49x60 n/d 22.2
GCN Circular 14273
Subject
GRB 111123A: Keck-I host detection and VLT/X-shooter redshift
Date
2013-03-08T10:59:57Z (12 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu, D. Malesani, T. Kruehler, J. P. U. Fynbo (DARK/NBI), D. A.
Perley (Caltech), P. Goldoni (APC/Univ. Paris 7 and SAp/CEA), L. Kaper
(U. Amsterdam), A. de Ugarte Postigo (IAA-CSIC and DARK/NBI), N. R.
Tanvir (U. Leicester) report on behalf of the X-shooter GTO GRB
collaboration:
We observed the field of GRB 111123A (Stamatikos et al., GCN 12587)
using the Keck-I telescope equipped with the LRIS instrument.
Observations were carried out on 2013 February 10 (~444 days after the
burst), simultaneously in the g and I bands, for a total exposure time
of 750 and 720 s, respectively.
An extended source with g=25.83 (AB) and I = 23.55 (Vega) is detected
at the position of the optical and NIR afterglow (Xu et al., GCN
12589; Fugazza et al., GCN 12593), where the positional error radius
of the optical afterglow has been reduced from ~1.0" to ~0.3" through
a refined analysis. We thus consider the source to be the host galaxy
of GRB 111123A.
A spectrum of this source was taken on 2013 March 07 with the ESO VLT
equipped with the X-shooter spectrograph, featuring NIR/VIS/UVB three
arms and covering the wavelength range 3000-25000 AA. The exposure
time was 4x600 s. In the NIR arm, we detect four emission lines,
interpreted as [O III] (5007), [NeIII] (3869), [O II] (3727), and
Hbeta (a marginal detection), all at a common redshift z = 3.1516. In
the UVB arm, the host continuum is detected down to ~5100 AA, thus
corresponds to the onset of the Lyman alpha forest at the proposed
redshift.
We acknowledge excellent support from the observing staff at Mauna Kea
and Paranal, in particular Emanuela Pompei, Claudio Melo, and Andres
Pino.