GRB 120324A
GCN Circular 13090
Subject
GRB 120324A: Swift detection of a burst
Date
2012-03-24T06:14:22Z (13 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
B.-B. Zhang (PSU), A. P. Beardmore (U Leicester), D. Grupe (PSU),
C. Guidorzi (U Ferrara), E. A. Hoversten (PSU),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:
At 05:59:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 120324A (trigger=518507). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 291.084, +24.145 which is
RA(J2000) = 19h 24m 20s
Dec(J2000) = +24d 08' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of about 90 sec. The peak count rate
was ~10500 counts/sec (15-350 keV), at ~34 sec after the trigger.
The XRT began observing the field at 06:00:26.4 UT, 75.1 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 291.0771, 24.1290 which is equivalent to:
RA(J2000) = +19h 24m 18.50s
Dec(J2000) = +24d 07' 44.4"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 61 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.
The initial flux in the 2.5 s image was 1.92e-08 erg cm^-2 s^-1 (0.2-10
keV).
No UVOT data are available at this time.
Burst Advocate for this burst is B.-B. Zhang (bbzhang AT 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 13091
Subject
GRB 120324A: UVOT Finding Chart Observation
Date
2012-03-24T06:32:25Z (13 years ago)
From
Erik Hoversten at Swift/Penn State <hoversten@astro.psu.edu>
E. A. Hoversten (PSU) and B.-B. Zhang (PSU) report on behalf of the
Swift/UVOT team:
In response to GRB120324A (Swift/BAT trigger 518507, Zhang et al. GCN Circ.
13090) at 05:59:11 UT, UVOT took a finding chart exposure of 150 seconds
with the White filter starting 84 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. Because of the density of
catalogued stars, further analysis is required to report an upper limit for any
afterglow in the sub-image. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. Because of the density of
catalogued stars, further analysis is required to report an upper limit for any
afterglow in the region. No correction has been made for the large, but uncertain
extinction expected.
GCN Circular 13092
Subject
GRB 120324A: Liverpool Telescope optical candidate
Date
2012-03-24T07:10:25Z (13 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), A. Melandri (INAF-OAB),
report on behalf of the LJMU GRB group:
The 2-m Liverpool Telescope automatically observed
Swift GRB 120324A (Zhang et al. GCN Circ. 13090)
on March 24, from 06:13:42 UT, corresponding to
14.5 minutes after the BAT trigger time.
Within the XRT error circle we detect an uncatalogued
object with 20.3 +- 0.3 mag in the r' band at the
following position
19:24:18.76 +24:07:50.1 (J2000).
At the moment we cannot make any statement about its
possible variability.
Magnitudes are calibrated against nearby USNOB-1 stars.
GCN Circular 13093
Subject
GRB 120324A: Enhanced Swift-XRT position
Date
2012-03-24T09:08:32Z (13 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1195 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 120324A, 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 = 291.07873, +24.12958 which is equivalent
to:
RA (J2000): 19h 24m 18.90s
Dec (J2000): +24d 07' 46.5"
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 13094
Subject
GRB 120324A: TAROT La Silla observatory optical observations
Date
2012-03-24T11:35:21Z (13 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 120324A detected by SWIFT
(trigger 518507) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.
The observations started 1.98h after the GRB trigger
(it was not risen when the GRB occured).
The elevation of the field increased from
11 degrees above horizon and weather conditions
were good.
We co-added a long series of exposures. We do not
detect any OT in the XRT enhanced position (Evans et al.
GCNC 13093):
start end magnitude
tgrb+1.98h tgrb+3.23h R > 19.7
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 58.0588 lat= +4.0337
and the galactic extinction in R band is about 3 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
GCN Circular 13095
Subject
GRB 120324A: Swift/UVOT Upper Limits
Date
2012-03-24T12:36:49Z (13 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (MSSL-UCL) and B.-B. Zhang (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 120324A
84 s after the BAT trigger (Zhang et al., GCN Circ. 13090).
No optical afterglow, consistent with the XRT position
(Evans et al., GCN Circ. 13093) or the uncatalogued
object reported by the Liverpool Telescope (Guidorzi et al., GCN Circ. 13092),
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
white_FC 84 234 147 >21.2
u_FC 297 547 246 >20.2
white 84 4917 569 >22.1
v 627 5329 294 >19.9
b 553 1510 89 >19.6
u 297 1493 324 >20.2
w1 676 5615 171 >19.9
m2 652 5534 216 >20.0
w2 603 5124 274 >20.8
The magnitudes in the table are not corrected for the significant Galactic extinction
due to the reddening of E(B-V) = 1.12 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 13096
Subject
GRB 120324A: Swift-BAT refined analysis
Date
2012-03-24T14:25:10Z (13 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
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), B.-B. Zhang (PSU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 120324A (trigger #518507)
(Zhang, et al., GCN Circ. 13090). The BAT ground-calculated position is
RA, Dec = 291.081, 24.140 deg, which is
RA(J2000) = 19h 24m 19.5s
Dec(J2000) = +24d 08' 23.6"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
The mask-weighted light curve shows many overlapping peaks starting
at ~T-190 sec with a weak precursor peak, the main peak at ~T+33 sec, and
ending at ~T+180 sec (and possible as long as ~T+330 sec at the 2-sigma level).
T90 (15-350 keV) is 118 +- 10 sec (estimated error including systematics).
The time-averaged spectrum from T-150.5 to T+142.5 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.34 +- 0.04. The fluence in the 15-150 keV band is 1.01 +- 0.03 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+33.68 sec in the 15-150 keV band
is 5.9 +- 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/518507/BA/
GCN Circular 13097
Subject
GRB 120324A: CQUEAN rizY Observation
Date
2012-03-24T15:47:25Z (13 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Myungshin Im, Jae-Woo Kim, and Duho Kim (CEOU/Seoul National Univ.)
We observed GRB 120324A (Zhang et al., GCN 13090) in
r,i,z,Y filters using CQUEAN camera on the 2.1m Otto-Struve
telescope at McDonald Observatory, Texas, US.
The observation started at 2012-03-24 10:31:44 UT,
or about 4.5 hours after the BAT alert.
We find a faint object in i,z,Y images at the edge of
the error circle of the enhanced XRT position
(Evans et al. GCN 13093).
The coordinate of the object is
RA=19:24:18.78, Dec=24:07:47.3 (J2000)
with an error of 0.7".
Due to high stellar density in this field, it is not clear
if this object is the optical counterpart of the GRB
Further observations are planned to check the variability
of this source. The finding chart of the object is available at
http://astro.snu.ac.kr/~mim/grb120324a/grb120324a_cquean_i.gif
We note that an optical candidate reported by
Guidorzi et al. (GCN 13092) is clearly seen in both a POSS2 image
retrieved from the Digitized Sky Survey and our CQUEAN images,
making it less likely that the object is a GRB afterglow.
We thank Karl Gebhardt and his observing team for their help
with the observation.
GCN Circular 13098
Subject
GRB 120324A: GROND observations
Date
2012-03-24T15:53:34Z (13 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
V. Sudilovsky (MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg), and
J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 120324A (Swift trigger 518507; Zhang et al.,
GCN #13090) 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 09:04 UT, approx. 3 hrs after the GRB trigger and
lasted for approx. 35 min. They were performed at an average seeing of
1.0" and at high airmass.
The source reported by Guidorzi et al. (GCN #13092) is clearly detected at
a constant brightness of r' = 20.3 +/- 0.2. The lack of fading and
location outside the enhanced XRT error circle argue against an
association with the GRB.
In addition, we detect a single source at the border of the XRT error
circle at coordinates
RA (J2000): 19h 24m 18.80s
Dec (J2000): +24d 07' 47.4" (+/- 0.5")
at a brightness of r' ~ 22.6 mag. This source has an extended morphology
and could be the host galaxy (see also Im et al., GCN 13097).
Magnitudes have been calibrated against GROND zeropoints. We note that
there is a significant Galactic foreground reddening of E(B-V) ~ 1.2 mag
(Schlegel et al. 1998).
GCN Circular 13100
Subject
Konus-Wind observation of GRB 120324A
Date
2012-03-24T17:02:59Z (13 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long GRB 120324A (Swift-BAT trigger #518507:
Zhang et al., GCN 13090; Cummings et al., GCN 13096)
triggered Konus-Wind at T0=21550.757s UT (05:59:10.757)
The light curve shows multiple peaks
with a total burst duration of ~65 s.
The emission is seen up to ~9 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB120324_T21550/
As observed by Konus-Wind the burst
had a fluence of (4.5 � 1.2)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+0.768 s,
of (3.7 � 0.9)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+41.216 s)
is best fitted in the 20 keV - 10 MeV range
with the GRB (Band) model, for which:
the low-energy photon index alpha = -1.02 (-0.10, +0.11),
the high energy photon index beta = -2.3 (-1.0, +0.3),
the peak energy Ep = 445(-80, +117) keV,
chi2 = 82.3/86 dof.
The spectrum at the maximum count rate
(measured from T0 to T0+8.448 s) is best fitted
is best fitted in the 20 keV - 10 MeV range
with the GRB (Band) model, for which:
the low-energy photon index alpha = -0.87 (-0.12, +0.15),
the high energy photon index beta = -2.6 (<-2.1),
the peak energy Ep = 504(-103, +135) keV,
chi2 = 90.9/86 dof.
All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.
GCN Circular 13101
Subject
GRB 120324A: Swift-XRT refined Analysis
Date
2012-03-24T18:14:04Z (13 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
B. Sbarufatti (INAF-OAB/PSU), 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), G. Stratta (ASDC), P. D'Avanzo
(INAF-OAB) and B.-B. Zhang report on behalf of the Swift-XRT team:
We have analysed 8.3 ks of XRT data for GRB 120324A (-B. Zhang et al.
GCN Circ. 13090), from 81 s to 29.5 ks after the BAT trigger. The data
comprise 160 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN. Circ 13093).
The late-time light curve (from T0+4.7 ks) can be modelled with a
power-law decay with a decay index of alpha=1.04 (+/-0.07).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.12 (+/-0.10). The
best-fitting absorption column is 1.10 (+0.09, -0.08) x 10^22 cm^-2,
in excess of the Galactic value of 4.5 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.07 (+/-0.14) and a
best-fitting absorption column of 1.18 (+0.13, -0.12) x 10^22 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 5.7 x 10^-11 (1.3 x 10^-10) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.18 (+0.13, -0.12) x 10^22 cm^-2
Galactic foreground: 4.5 x 10^21 cm^-2
Excess significance: 9.9 sigma
Photon index: 2.07 (+/-0.14)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00518507.
This circular is an official product of the Swift-XRT team.
GCN Circular 13174
Subject
GRB 120324A, the review of the sky area in plate archives
Date
2012-03-30T18:01:07Z (13 years ago)
From
Valentyna Golovnya at Main Astro Obs,Kyiv <golov_v@ukr.ne>
V.V.Golovnya (Main Astro Obs, Kyiv)
report:
We have undertaken the review of the sky area in vicinity of
GRB 120324A (P.A. Evans et al. GCN Circ.13093) 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 and Epson Expression 10000XL flatbed
scanners 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 Star USNOA2
19880831/190518 GUA040C001326A 16.0 14.55 1125-12506783
19890803/201455 GUA040C001494A 16.0 15.65 1125-12498949
19890803/204023 GUA040C001495 16.0 15.65 1125-12498949
19910807/205429 GUA040C001847 16.0 16.40 1125-12498743
Plates: � the plates archive identifier of DWA (D/F=400/2000,
GUA040C M=103"/mm) of the Ukrainian NAS Main Astro obs.
(Marsden's number - 83) the plate number [1].
Exp. - Duration of the maximum exposure (minutes).
LimM - Limited V mag, derived in the 24 minutes area around
the location given in P.A. Evans et al. GCN Circ.13093:
RA(J2000)= 19h 24m 18.90s, Dec(J2000)= +24d 07' 46.5"
Star USNOA2 - Comparison star.
The preview images of 4 areas together with
the 24x24 min.of arc area from SkyMap can be found in
http://gua.db.ukr-vo.org/img/grb/120324A/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 13179
Subject
GRB 120324A: CrAO optical upper limit
Date
2012-03-31T11:30:44Z (13 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev, K. Antonyuk (CrAO), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:
We observed the field of GRB 120324A (Zhang et al., GCN 13090) with AZT-11
telescope of CrAO observatory starting on March 25 (UT) 01:46:17 under
moderate weather conditions and seeing of about 2.7 arsces. Within
enhanced Swift-XRT position (Evans et al., GCN 13093) we do not detected
any optical source up to R=20.7. The source reported in (Guidorzi et al.,
GCN 13092; Im et al., GCN 13097; Sudilovsky et al., GCN 13098) is clearly
detected and have a brightness R=20.16 +/-0.25. A photometry is based on
the USNO-B1.0 star 1141-0365943 (19 24 20.29 +24 07 58.2) assuming
R=17.07:
T0+ Filter, Exposure, OT, uplim (3 sigma)
(mid, d) (s)
0.8411 R 16x180 n/d 20.7