GRB 121211A
GCN Circular 14057
Subject
GRB 121211A: Swift detection of a burst with an optical counterpart
Date
2012-12-11T14:00:52Z (13 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
V. Mangano (INAF-IASFPA), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
M. M. Chester (PSU), V. D'Elia (ASDC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), S. T. Holland (STScI), J. A. Kennea (PSU),
A. Maselli (INAF-IASFPA), K. L. Page (U Leicester),
B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU),
E. Sonbas (NASA/GSFC/Adiyaman Univ.), R. L. C. Starling (U Leicester)
and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team:
At 13:47:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 121211A (trigger=541200). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 195.544, +30.161 which is
RA(J2000) = 13h 02m 11s
Dec(J2000) = +30d 09' 40"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows multiple peaks
with a total duration of about 180 sec. The peak count rate
was ~800 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 13:48:32.3 UT, 89.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 195.5332, 30.1489 which is equivalent to:
RA(J2000) = +13h 02m 7.97s
Dec(J2000) = +30d 08' 56.0"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 55 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 96 seconds after the BAT trigger. There is a candidate afterglow in
the list of sources generated on-board at
RA(J2000) = 13:02:08.01 = 195.53339
DEC(J2000) = +30:08:54.9 = 30.14858
with a 90%-confidence error radius of about 1.10 arc sec. This position is 1.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.49. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.01.
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.)
GCN Circular 14058
Subject
GRB 121211A - Faulkes Telescope North afterglow confirmation
Date
2012-12-11T14:34:34Z (13 years ago)
From
Jure Japelj at U. of Ljubljana,Slovenia <jure.japelj@fmf.uni-lj.si>
J. Japelj, D. Kopa�� (U. Ljubljana), C. Guidorzi (U. Ferrara), C. Mundell,
F. Virgili (Liverpool JMU) report on behalf of a large collaboration:
The 2-m Faulkes Telescope North automatically began observing
GRB 121211A (Mangano et al. GCN Circ. 14057) on Dec 11 2012,
13:50:46 UT corresponding to 224 seconds post burst trigger. We confirm
the presence of a fading source at the optical afterglow candidate position
reported by Mangano et al. GCN Circ. 14057. In the first 3x10 s exposure,
we measure a preliminary R magnitude of 17.9 +- 0.3, calibrated against
nearby USNO-B1 stars.
GCN Circular 14059
Subject
GRB 121211A: Keck/LRIS redshift
Date
2012-12-11T18:38:05Z (13 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech), J. X. Prochaska (UCO/Lick), and A. N. Morgan (UC
Berkeley) report:
We slewed with the Keck I telescope (+LRIS) to the location of GRB
121211A (Mangano et al., GCN 14057) immediately following the GCN
notice. The optical transient (Mangano et al.; Japelj et al., GCN
14058) was identified on the guider camera and longslit exposures began
at 14:01 UT, 14 minutes after the GRB trigger. After a single short
observation in low resolution we acquired 2x860s exposures on the blue
and red side. The spectral range extends from 3150-5630 and 5790-7440
Angstroms.
We identify FeII (2344, 2374, 2382, 2586, 2600) and possible FeII* and
MnII at a redshift of z=1.023, as well as a marginal detection of MgII
(2796, 2804) at the same redshift using the short initial exposure,
which covers the dichroic gap. We suggest this as the redshift of GRB
121211A.
GCN Circular 14060
Subject
GRB 121211A: Enhanced Swift-XRT position
Date
2012-12-11T21:08:53Z (13 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 2289 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 121211A, 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 = 195.53315, +30.14869 which is equivalent
to:
RA (J2000): 13h 02m 7.96s
Dec (J2000): +30d 08' 55.3"
with an uncertainty of 1.6 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 14061
Subject
GRB 121211A: Swift-XRT refined Analysis
Date
2012-12-12T02:01:06Z (13 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
D.N. Burrows (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), A. Maselli (INAF-IASFPA), A.
Melandri (INAF-OAB), J.A. Kennea (PSU), M.C. Stroh (PSU) and V. Mangano
report on behalf of the Swift-XRT team:
We have analysed 12 ks of XRT data for GRB 121211A (Mangano et al. GCN
Circ. 14057), from 95 s to 29.5 ks after the BAT trigger. The data
comprise 203 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN. Circ 14060).
The late-time light curve (from T0+3.9 ks) can be modelled with a
power-law decay with a decay index of alpha=0.77 (+/-0.07).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.15 (+/-0.04). The
best-fitting absorption column is 2.85 (+/-0.13) x 10^21 cm^-2, in
excess of the Galactic value of 9.5 x 10^19 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.11 (+0.15, -0.14)
and a best-fitting absorption column of 1.4 (+0.4, -0.3) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.5 x 10^-11 (5.0 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.4 (+0.4, -0.3) x 10^21 cm^-2
Galactic foreground: 9.5 x 10^19 cm^-2
Excess significance: 6.4 sigma
Photon index: 2.11 (+0.15, -0.14)
If the light curve continues to decay with a power-law decay index of
0.76, the count rate at T+24 hours will be 0.025 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.9 x
10^-13 (1.3 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00541200.
This circular is an official product of the Swift-XRT team.
GCN Circular 14062
Subject
GRB 121211A: MITSuME Okayama Optical Observation
Date
2012-12-12T02:38:27Z (13 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 121211A (Mangano et al., GCNC 14057)
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 2012-12-11 16:29:09 UT (~2.7 h after the burst).
We detected the previously reported afterglow (Japelj et al., GCNC 14058)
in all the three bands.
Photometric results and three sigma upper limit of the OT are listed below.
We used SDSS catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
-----------------------------------------------------------------------
0.15443 17:29:25 6360.0 >20.5 20.4 0.2 19.6 0.3
0.23818 19:30:01 6360.0 20.9 0.3 21.1 0.3 20.1 0.3
------------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 14063
Subject
GRB 121211A: Swift/UVOT Detection
Date
2012-12-12T03:15:42Z (13 years ago)
From
Margaret Chester at PSU <chester@astro.psu.edu>
M. M. Chester (PSU) and V. Mangano (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 121211A
97 s after the BAT trigger (Mangano et al., GCN Circ. 14057). A source
consistent with the enhanced Swift-XRT position (Osborne et al. GCN
Circ.
14060) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 13:02:07.99 = 195.53328 (deg.)
Dec (J2000) = +30:08:54.6 = 30.14849 (deg.)
with an estimated uncertainty of 0.52 arc sec. (radius, 90% confidence).
The following table provides preliminary detections and 3-sigma upper
limits for the finding charts and summed exposures using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373).
The lack of a detection in uvw2 is consistent with the redshift of
1.023 reported by Perley et al. (GCN Circ. 14059).
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 97 247 147 18.4 +/- 0.1
white 4103 5738 393 19.9 +/- 0.1
v 4514 6148 393 >19.9
b 3899 5533 393 20.4 +/- 0.2
u_FC 255 297 41 18.3 +/- 0.3
u 5128 5328 197 19.6 +/- 0.2
w1 10576 11476 886 20.6 +/- 0.2
m2 4718 10569 1082 20.6 +/- 0.2
w2 4309 5943 393 >21.1
The magnitudes in the table are not corrected for the Galactic
extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 14067
Subject
GRB 121211A: Swift-BAT refined analysis
Date
2012-12-12T13:36:02Z (12 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), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), V. Mangano (INAF-IASFPA), D. M. Palmer (LANL),
T. Sakamoto (AGU), 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 recent telemetry downlinks,
we report further analysis of BAT GRB 121211A (trigger #541200)
(Mongano, et al., GCN Circ. 14057). The BAT ground-calculated position is
RA, Dec = 195.575, 30.173 deg, which is
RA(J2000) = 13h 02m 18.0s
Dec(J2000) = +30d 10' 24.4"
with an uncertainty of 4.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 23%.
The mask-weighted light curve shows a peak starting at ~T-5 sec, peaking at
~T+2 sec, and returning to baseline at ~T+5 sec. Then a second set of peaks
starts at ~T+20 with the main emission from T+105 to ~T+200 sec.
T90 (15-350 keV) is 182 +- 39 sec (estimated error including systematics).
The time-averaged spectrum from T-0.48 to T+196.77 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.36 +- 0.26. The fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.07 sec in the 15-150 keV band
is 1.0 +- 0.3 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/541200/BA/
GCN Circular 14075
Subject
GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
Date
2012-12-13T01:05:47Z (12 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,
of Los Alamos National Laboratory report:
The RAPTOR network of robotic optical telescopes made observations of Swift
trigger 541200 (Mangano, et al., GCN 14057). The burst location was within
the field of our wide-field monitor located in Maui, HI, which began a 10 s
integration of the location at 03:47:00.17 UT, 2.8 s before the Swift trigger
time and during the gamma-ray emitting interval. During the period that the
BAT was detecting gamma-ray emission, from ~T-5 s to ~T+200 s (Barthelmy,
et al., GCN 14067), we have a total of twenty 10 s exposures with limiting
magnitudes of R~9.8. We do not detect the optical counterpart in any of
our images. Our 3-sigma limiting magnitudes are based on a comparison of
our unfiltered image to the Tycho-2 V-band catalog.
GCN Circular 14077
Subject
GRB 121211A: RATIR Optical and NIR Observations
Date
2012-12-13T04:12:26Z (12 years ago)
From
Nat Butler at UC berkeley <natxbutler@gmail.com>
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB),
Ori Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino
Cucchiara (UCSC), Eleonora Troja (GSFC), Enrico Ramirez���Ruiz (UCSC),
Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes��s Gonz��lez
(UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:
We observed the field of GRB 121211A (Mangano, et al., GCN 14057) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir from 2012 Dec 12.48 to 2012 Dec
12.58 UTC (21.8 to 24.1 hours after the BAT trigger), obtaining a
total of 1.8 hours exposures in the r' and i' bands and 0.67 hours of
exposure in the Z, Y, J, and H bands.
In comparison with SDSS DR8 and 2MASS, we derive the following
detections and upper limits (3-sigma) in the AB magnitude system:
r' 22.9 +/- 0.2
i' 23.2 +/- 0.2
Z 22.1 +/- 0.4
Y >21.3
J >21.9
H >21.1
These magnitudes are not corrected for Galactic extinction in the
direction of the GRB.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro M��rtir.
GCN Circular 14078
Subject
GRB 121211A: Fermi GBM observation
Date
2012-12-13T09:02:10Z (12 years ago)
From
Hoi-Fung Yu at MPE <sptfung@mpe.mpg.de>
David Yu (MPE) reports on behalf of the Fermi GBM Team:
"At 13:47:03.59 UT on 11 December 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 121211A (trigger 376926426 / 121211574)
which was also detected by the Swift/BAT (Mangano et al. 2012, GCN 14057).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 74 degrees.
The GBM light curve consists of a double peaked pulse
with a duration (T90) of about 5.4 s (50-300 keV).
The time-averaged spectrum from T0-3.072 s to T0+1.536 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.30 +/- 0.34 and
the cutoff energy, parameterized as Epeak, is 95.96 +/- 12.60 keV.
The event fluence (10-1000 keV) in this time interval is
(4.825 +/- 0.507)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.768 s in the 10-1000 keV band
is 2.402 +/- 0.202 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 14080
Subject
GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
Date
2012-12-13T22:56:58Z (12 years ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB)
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Enrico Ramirez���Ruiz (UCSC), Jos�� A. de Diego (UNAM),
Leonid Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 121211A (Mangano, et al., GCN 14057) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir for a second time from 2012 Dec 13.46 to 2012 Dec
13.57 UTC (45.2 to 47.8 hours after the BAT trigger), obtaining a total of
1.8 hours exposures in the r' and i' bands, 1.2 hours exposure in the Z and
J bands, and 10 minutes exposure in the Y and H bands.
For a source spatially coincident with the UVOT position (Chester et al.,
GCN 14063), in comparison with SDSS DR8 and 2MASS, we derive the following
detections and upper limits (3-sigma) in the AB magnitude system:
r' 23.8 +/- 0.3 (delta= -0.9 +/- 0.4)
i' 24.0 +/- 0.4 (delta= -0.8 +/- 0.4)
Z >22.4
Y >21.8
J >21.3
H >20.6
The delta values give the fade in 24 hours relative to the values quoted in
GCN 14077. These magnitudes are not corrected for Galactic extinction in
the direction of the GRB.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.