GRB 140330A

A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU),
D.N. Burrows (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), T.
Sbarrato (INAF-OAB) and  report on behalf of the Swift-XRT team: report
on behalf of the Swift-XRT team:

We have analysed 3.2 ks of XRT data for the Fermi/LAT-detected burst
GRB 140330A, from 102.0 ks to 120.0 ks after the  Fermi/LAT trigger.
The data are entirely in Photon Counting (PC) mode. The refined XRT
position is RA, Dec = 325.4425, -64.1882 which is equivalent to:

RA (J2000): 21 41 46.19
Dec(J2000): -64 11 17.4

with an uncertainty of 4.0 arcsec (radius, 90% confidence). This
position is 7.7 arcmin from the Fermi/LAT position.  The source has a
mean count rate of 2.4e-02 ct/sec; we cannot determine at the present
time whether it is fading.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.8 (+0.7, -0.5). The
best-fitting absorption column is  9 (+17, -5) x 10^20 cm^-2,
consistent with the Galactic value of 3.5 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 3.4 x 10^-11 (4.1 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     9 (+17, -5) x 10^20 cm^-2
Galactic foreground: 3.5 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.8 (+0.7, -0.5)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020372.

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

V. Pelassa (UAH), G. Fitzpatrick (UCD), C. Meegan and N. Bhat (UAH)
report on behalf of the Fermi GBM Team:

"At 04:19:54.47 UT on 30 March 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140330A (trigger 417845997 / 140330180),
which was also detected by Konus-Wind (S. Golenetskii et al, GCN 16056
Loading...
 
 )
and localized by the Interplanetary Network (K. Hurley et al, GCN 16051
Loading...
 
 ).
The GBM on-ground location is consistent with the IPN location.
The angle from the Fermi LAT boresight is 13.6 degrees.

The GBM light curve consists of a FRED pulse with a duration (T90)
of about 34 s (50-300 keV).

The time-averaged spectrum from T0-0.768 s to T0+35.073 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.66 +/- 0.10 and
the cutoff energy, parameterized as Epeak, is 197 +/- 17 keV.
(Castor statistics 578.62 for 486 d.o.f.).
A Band function fits the spectrum equally well (Castor statistics
577.22 for 485 d.o.f.) with Epeak= 172 +/- 23 keV,
alpha = -0.57 +/- 0.13 and beta = -2.4 +/- 0.3.
This result is consistent with the analysis of the Konus observation
(S. Golenetskii et al, GCN 16056
Loading...
 
 ).

The event fluence (10-1000 keV) in this time interval is
(5.6 +/- 0.3)E-06  erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.640 s in the 10-1000 keV band
is 4.3 +/- 0.2 ph/s/cm^2.

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

G. Vianello (Stanford U.), D. Kocevski (NASA/Goddard), J. Racusin
(NASA/Goddard), R. Ojha (NASA/GSFC/UMBC/CRESST) <Roopesh.Ojha@gmail.com>,
and S. Ciprini (ASDC) report on behalf of the Fermi-LAT team:

The analysis of new data downloaded from Fermi has shown that emission from
the proposed high-energy counterpart of GRB 140330A (Vianello et al., GCN
16048
Loading...
 
 ; Pittori et al., GCN 16058
Loading...
 
 ) has continued up to at least 40 ks after
the GBM trigger. This is very unusual for a faint burst such as GRB
140330A. Also, our localization of the LAT excess has improved, and it is
now:

R.A., Dec. = 325.40, -64.13 with an error radius of 0.14 (90 % c.l.,
statistical only),

which is well outside the IPN error box (Hurley et al., GCN 16051
Loading...
 
 ).

Moreover, a search in Fermi archival data has shown a variable emission
from a source compatible with our position, which was detected in several
occasions in 2012 and 2013, and also detected on March 28 and 29, 2014.
This source has been tentatively associated with the extra-galactic radio
source PKS 2136-642 in the past (ATel #5695; Mauch et al. 2003, MNRAS, 342,
1117).

Therefore, we believe that the high-energy source detected by Fermi and by
AGILE (Pittori et al., GCN 16058
Loading...
 
 ) is unrelated to GRB 140330A.

Further analysis is ongoing.

[GCN OPS NOTE(01apr14): Per author's request, the "130330A" was changed
to "140330A" in the Subject-line iand the 1st & 3rd paragraphs.]

C. Pittori, F. Verrecchia (ASDC and INAF/OAR),
A. Bulgarelli (INAF/IASF-Bo), A. Giuliani (INAF/IASF-Mi),
M. Tavani (INAF/IAPS Rome, and Univ. Roma Tor Vergata), P. Caraveo 
(INAF/IASF-Mi), F. Lucarelli (ASDC and INAF/OAR), M. Marisaldi
(INAF/IASF-Bo), F. Longo (Univ. of Trieste and INFN Trieste), E. Del
Monte, F. Lazzarotto, I. Donnarumma, Y. Evangelista, M. Feroci,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda (INAF/IAPS
Rome), G. Barbiellini, (INFN Trieste), F. Fuschino, F. Gianotti,
M. Trifoglio, G. Di Cocco, C. Labanti, V. Fioretti, M. Galli
(INAF/IASF-Bo), S. Mereghetti, F. Perotti (INAF/IASF-Mi), M. Cardillo,
E. Striani, (INAF/IAPS Rome, and Univ. Roma Tor Vergata), A. Argan,
G. Piano, S. Sabatini, V. Vittorini (INAF/IAPS Rome), G. Pucella (ENEA
Frascati), A. Pellizzoni, A. Trois (INAF/OA Cagliari), M. Pilia
(ASTRON), S. Vercellone (INAF/IASF-Pa), P. W. Cattaneo, A. Rappoldi
(INFN Pavia), A. Morselli, P. Picozza (INFN Roma-2), M. Prest,
E. Vallazza (Universita` dell'Insubria), P. Lipari, D. Zanello (INFN
Roma-1), A. Chen (Wits University), S. Colafrancesco (INAF/OAR and Wits
University), P. Giommi, and G. Valentini (ASI),
on behalf of the AGILE Team, report:


The AGILE Gamma Ray Imaging Detector (GRID) observed an intense and
prolonged high-energy emission above 100 MeV from GRB 140330A
(Fermi-LAT detection: G. Vianello et al., GCN 16048
Loading...
 
 ).

Despite a data telemetry gap of about 30 minutes occurring during the
prompt emission of this GRB, a maximum likelihood analysis of the
AGILE-GRID data integrated from 2014-03-30 04:50 UT (1805 s since
trigger time) to 2014-03-31 08:00 UT yields a detection at a
significance level larger than 4 sigma, with an average flux of
F=(2.30 +/- 0.98) 10-6 ph/cm2/s (E > 100 MeV).

Due to the high fluence of this burst at E>100 MeV, comparable only to
the one of GRB 130427A as recorded in the AGILE database, it was
possible to derive its properties using the maximum likelihood
techniques routinely used in the standard data analysis of AGILE-GRID
point sources.

This measurement was obtained with AGILE observing a large portion of
the sky in spinning mode.

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:

The long-duration GRB 140330A
(Fermi LAT detection: Vianello, Kocevski, & Racusin, GCN 16048
Loading...
 
 ;
IPN triangulation: Hurley at al., GCN 16051
Loading...
 
 )
triggered Konus-Wind at T0=15594.217 s UT (04:19:54.217).

The burst light curve shows a single pulse from ~T0-3 s to ~T0+15 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 3.9(-0.5,+0.6)x10-6 erg/cm2,
and a 64-ms peak flux, measured from T0+0.320 s,
of 1.5(-0.4,+0.4)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 18 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.60(-0.45,+0.55),
and the peak energy Ep = 158(-24,+34) keV,
chi2 = 105/96 dof.
Fitting this spectrum with the Band model yields the same
values of alpha and Ep with an upper limit on beta of -3.3.

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 cutoff power law with the following model parameters:
the photon index alpha = -0.18(-0.45,+0.55),
and the peak energy Ep = 172(-21,+28) keV,
chi2 = 89.2/95 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140330_T15594/

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

G. Vianello (Stanford U.), D. Kocevski (NASA/Goddard), and J. Racusin (NASA/Goddard) report on behalf of the Fermi-LAT team:

At 04:19:54.47 UT on March 30, 2014, Fermi-LAT detected high-energy emission from GRB 140330A, which was also detected by Fermi-GBM (trigger 417845997).

The best LAT on-ground location is found to be

RA, Dec 325.59, -64.30 (J2000)

with an error radius of 0.2 deg (90% containment, statistical error only). This was within 15 deg from the LAT boresight at the time of the trigger.  More than 10 photons above 100 MeV and 2 photons above 1 GeV are observed within 6000 seconds after the GBM trigger. The highest-energy photon is a 4.5 GeV event, which is observed 252 seconds after the GBM trigger.

A Swift ToO has been requested and accepted for this burst.

The Fermi-LAT point of contact for this burst is Daniel Kocevski (daniel.kocevski@<mailto:xxxx@xxx.xxx>nasa.gov<http://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.