GRB 140323A

A. Klotz, D. Turpin (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. 
Coward (UWA),
M. Boer, B. Gendre, K. Siellez, H. Dereli, O. Bardho (UNS-CNRS-OCA),
A. Williams (PO-UWA), R. Martin (PO-UWA)
report:

We imaged the field of GRB 140323A detected by SWIFT
(trigger 592916) with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia.

The observations started 1.0 hour after the GRB trigger.
The elevation of the field was at 27 degrees above
horizon and weather conditions were good.

We co-added a series of exposures. We do not
detect any optical candidate in the XRT error box
provided by Troja et al. (GCNC 16027) at the
limiting magnitude of:

 From t0+1.0h to t0+1.6h Rlim=20.8

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=306.3802 lat=-36.7801

W. Iwakiri(RIKEN), M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, H. Ueno,
S. Sugimoto, S. Koyama, S. Takeda, T. Nagayoshi (Saitama U.),
M. Yamauchi, N. Ohmori, M. Akiyama, R. Kinoshita (Univ. of Miyazaki),
M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa (Hiroshima U.),
K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.),
Y. Hanabata (ICRR), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA),
Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo)
on behalf of the Suzaku WAM team, report:


The long GRB 140323A (Swift/BAT trigger #592916 ; Troja et al., GCN
16027
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 ; Sakamoto et al., GCN 16029
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 ; Fermi-GBM detection : Yu and von
Kienlin, GCN 16032
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 ; Fermi-LAT detection: Vianello et al., GCN 16034
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 ;
Konus-Wind detection : Golenetskii et al., GCN16035
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 ) triggered the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 10:23:12.262 UT (=T0).

The observed light curve shows a multi-peaked structure in two main
episodes lasting from T0-15 s to T0+95 s with a duration (T90) of about
90 seconds. The fluence in 100 - 1000 keV was 1.36 (+/- 0.12) x10^-6 erg/cm^2.
The 1-s peak flux measured from T0+6 s was 2.17 (+0.35, -0.45)
photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-10 s to
T0+95 s is well fitted in 200 keV to 5 MeV by a single power-law with a
photon index of 2.64 (+0.34, -0.28) (chi^2/d.o.f = 12.5/14).

All the quoted errors are at statistical 90% confidence level, in which
the systematic uncertainties are not included.

The light curves for this burst will be available at:

http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline
on behalf of the Konus-Wind team, report:

A long-duration GRB 140323A (Swift-BAT trigger 592916:
Troja et al., GCN 16027
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 ; Sakamoto et al., GCN 16029
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 ;
Fermi-GBM detection: Yu & von Kienlin, GCN 16032
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 ;
Fermi-LAT detection: Vianello et al., GCN 16034
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 )
triggered Konus-Wind at T0=37392.356 s UT (10:23:12.356).

The burst light curve shows multiple peaks in two major bursting episodes.
A total duration of the burst is ~130 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence
of 3.1(-0.4,+0.7)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0+5.376 s, of 3.2(-0.6,+0.7)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+106.752 s)
is best fit in the 20 keV - 18 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.09 (-0.15,+0.31),
the high energy photon index beta = -3.0 (-7.0,+0.6),
the peak energy Ep = 127 (-24,+16) keV,
chi2 = 93.4/97 dof.

The spectrum near the maximum count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 18 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.79 (-0.18,+0.20),
the high energy photon index beta = -2.7 (-6.0,+0.3),
the peak energy Ep = 184 (-24,+31) keV,
chi2 = 96.8/87 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140323_T37392/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

G. Vianello (Stanford), F. Longo and E. Bissaldi (University and
INFN Trieste) report on behalf of the Fermi-LAT team:

On March 23, 2014, Fermi-LAT detected high-energy emission from
GRB 140323A, initially detected by Swift (Troja et al., GCN 16027
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 )
and also detected by Fermi-GBM (Yu et al., GCN 16032
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 ).
We note that the GBM and the Swift trigger times are different.
Here we will use as a reference the GBM trigger time,
i.e. 10:22:53.12 UT.

The data from the Fermi-LAT show a significant increase
in the event rate within 10 degrees of the Swift location.
More than 11 photons above 100 MeV and 3 photons above 1 GeV
are observed within 1000 seconds from the GBM trigger time.
The highest-energy photon is a 2.5 GeV event,
which is observed ~220 seconds after the trigger.

The best LAT on-ground location is found to be

RA, Dec 356.46, -79.87 (J2000)

with an error radius of 0.19 deg (90% containment, statistical
error only). This is 0.09 deg from the Swift/XRT localization
(GCN 16028
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 ) and is consistent with it.
The source was 31 deg from the LAT boresight
at the time of the trigger.

The Fermi-LAT point of contact for this burst is
Daniel Kocevski (daniel.kocevski@nasa.gov).

The Fermi-LAT is a pair conversion telescope designed
to cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration
between NASA and DOE in the U.S. and many scientific
institutions across France, Italy, Japan and Sweden.

B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC),
M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), A.P. Beardmore
(U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester)
and E. Troja report on behalf of the Swift-XRT team:

We have analysed 6.3 ks of XRT data for GRB 140323A (Troja  et al. GCN
Circ. 16027
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 ),  from 90 s to 34.5 ks after the  BAT trigger. The data
comprise 650 s in Windowed Timing (WT) mode (the first 6 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. 16028
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 ).

The late-time light curve (from T0+5.7 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.30 (+/-0.09).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.73 (+/-0.06). The
best-fitting absorption column is  5.0 (+/-0.4) x 10^21 cm^-2, in
excess of the Galactic value of 7.9 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.00 (+/-0.12) and a
best-fitting absorption column of 5.3 (+/-0.7) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.2 x 10^-11 (6.8 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     5.3 (+/-0.7) x 10^21 cm^-2
Galactic foreground: 7.9 x 10^20 cm^-2
Excess significance: 10.8 sigma
Photon index:	     2.00 (+/-0.12)

If the light curve continues to decay with a power-law decay index of
1.30, the count rate at T+24 hours will be 0.033 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.4 x
10^-12 (2.3 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/00592916.

This circular is an official product of the Swift-XRT team.

Subject: GRB 140323A: Fermi GBM observation

Hoi-Fung Yu and Andreas von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 10:22:53.12 UT on 23 March 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140323A (trigger 417262976 / 140323433),
which was also detected by Swift/BAT and XRT (Troja et al. 2014, GCN 16027
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 ).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 31 degrees.

The GBM light curve consists of multiple peaks in two main episodes
with a duration (T90) of about 111 s (50-300 keV).
The time-averaged spectrum from T0-2.560 s to T0+138.755 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.09 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 142 +/- 4 keV

The event fluence (10-1000 keV) in this time interval is
(3.15 +/- 0.05)E-05 erg/cm^2. The 1.024 s peak photon flux measured
starting from T0+25.0884 s in the 10-1000 keV band
is 9.7 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

M. Jelinek, J. C. Tello, R. Cunniffe, S. Jeong, O. Lara-Gil, J. Gorosabel
(IAA-CSIC Granada), P. Kub�nek (IP-ASCR Praha), M. Wildi (Obs. Vermes),
Ph. Yock (Univ. of Auckland), W. H. Allen (Vintage Lane Observatory) and
A. J. Castro-Tirado (IAA-CSIC), on behalf of a larger collaboration,
report:

"Following the detection of GRB 140323A by Swift (Troja et al., GCNC
16027), the 0.6m YA robotic telescope at the BOOTES-3 astronomical station
in Blenheim (New Zealand), responded ito the Swift BAT alert #592916. The
co-add of the second set of unfiltered images starting at 10:26:15 UT and
ending at 10:35:02 UT (i.e. 184-710 s postburst) reveals no optical
afterglow at the enhanced Swift XRT position (Osborne et al., GCNC 16028)
down to 18.5 mag. A first set only provides a shallower limit."

M. De Pasquale (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140323A
106 s after the BAT trigger (Troja et al., GCN Circ. 16027
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 ).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 16028
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 ) 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           106          256          147         >20.4
u_FC               319          569          246         >19.5
white              106          793          186         >20.5
v                  649         5918          216         >19.1
b                  574        12334          773         >20.2
u                  319         6532          462         >19.9
w1                 698         6328          216         >19.5
m2                5923        16174          725         >20.4
w2                 798          818           19         >17.9

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).

T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), J. Tueller (GSFC),
T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+693 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140323A (trigger #592916)
(Troja, et al., GCN Circ. 16027
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 ).  The BAT ground-calculated position is
RA, Dec = 356.975, -79.916 deg which is
    RA(J2000)  =  23h 47m 54.1s
    Dec(J2000) = -79d 54' 57.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 12%.

The mask-weighted light curve shows a complex structure.  Low-level emission
starts around T-60 sec, then the first episode runs from T-20 to T+55 sec, and
is a slow rise and fall with multiple sub-peaks superimposed.  The second
episode has a similar shape and runs from T+60 to T+110 sec, followed by
more low-level emission out to T+140 sec.  The second episode is spectrally
softer than the first. T90 (15-350 keV) is 104.9 +- 2.6 sec (estimated error
including systematics).

The time-averaged spectrum from T-7.09 to T+117.37 sec is best fit by a
power law with an exponential cutoff.  This fit gives a photon index 1.35 +- 0.17,
and Epeak of 127.1 +- 59.2 keV (chi squared 50.15 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 1.6 +- 0.0 x 10^-05 erg/cm2
and the 1-sec peak flux measured from T+6.42 sec in the 15-150 keV band is
6.2 +- 0.7 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.64 +- 0.04 (chi squared 59.02 for 57 d.o.f.).  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/592916/BA/

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 876 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 140323A, 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 = 356.95962, -79.90455 which is equivalent
to:

RA (J2000): 23h 47m 50.31s
Dec (J2000): -79d 54' 16.4"

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.

E. Troja (NASA/GSFC/UMCP), V. D'Elia (ASDC),
H. A. Krimm (CRESST/GSFC/USRA), C. J. Mountford (U Leicester),
K. L. Page (U Leicester) and T. N. Ukwatta (MSU) report on behalf of
the Swift Team:

At 10:23:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140323A (trigger=592916).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 356.888, -79.917 which is 
   RA(J2000) = 23h 47m 33s
   Dec(J2000) = -79d 55' 00"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 120 sec.  The peak count rate
was ~6700 counts/sec (15-350 keV), at ~89 sec after the trigger. 

The XRT began observing the field at 10:24:49.4 UT, 97.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 356.9593,
-79.9050 which is equivalent to:
   RA(J2000)  = 23h 47m 50.23s
   Dec(J2000) = -79d 54' 17.9"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 62 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 consistent with the Galactic value of 7.93
x 10^20 cm^-2 (Willingale et al. 2013). 

The initial flux in the 0.1 s image was 1.95e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 105 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
0.14. 

Burst Advocate for this burst is E. Troja (eleonora.troja 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.)