GRB 141011A

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:

"At 06:46:20.36 UT on 11 October 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 141011A (trigger 434702783 / 141011282).

The trigger resulted in an Autonomous Repoint Request (ARR)
that was accepted and the spacecraft slewed to the GBM in-flight location.

The on-ground calculated location, using the GBM trigger
data, is RA = 254.9, DEC = -8.3 (J2000 degrees,
equivalent to 16h 59m, -08d 18'), with an uncertainty
of 2.7 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 32 degrees.

The GBM light curve consists of a short structured pulse
with a duration (T90) of about 0.1 s (50-300 keV).
The time-averaged spectrum from T0-0.16 s to T0+0.080 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.50 +/- 0.09 and
the cutoff energy, parameterized as Epeak, is 603 (+78/-63)keV

The event fluence (10-1000 keV) in this time interval is
(1.05 +/- 0.05)E-06 erg/cm^2. The 0.016-sec peak photon flux measured
starting from T0-0.16 s in the 10-1000 keV band
is 70 +/- 4 ph/s/cm^2.

A Band function fits the spectrum equally well with 
Epeak= 573 (+90/-75) keV, alpha = -0.5 +/- 0.1 and beta = -2.7 (+0.4/-4.2).

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

S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley on behalf of the IPN,

J. Goldsten, on behalf of the MESSENGER NS GRB team,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team,

V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa,
on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, report:

The short-duration, hard-spectrum, bright GRB 141011A (von Kienlin, GCN 
Circ. 16905
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 ) has been observed by Fermi (GBM trigger 434702783), 
Konus-Wind, MESSENGER (GRNS), Mars Odyssey (HEND), Swift (BAT), and 
INTEGRAL (SPI-ACS), so far, at about 24380 s UT (06:46:20). The burst 
was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   257.939 (17h 11m 45s)  -9.681 ( -9d 40' 52")
  Corners:
   257.903 (17h 11m 37s)  -9.336 ( -9d 20' 10")
   257.999 (17h 12m 00s)  -9.336 ( -9d 20' 09")
   257.975 (17h 11m 54s) -10.026 (-10d 01' 34")
   257.878 (17h 11m 31s) -10.027 (-10d 01' 36")
  ---------------------------------------------
The error box area is 236 sq. arcmin, and its maximum
dimension is 42 arcmin (the minimum one is 6 arcmin).

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB141011_T24377/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.

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

The short-duration, hard-spectrum GRB 141011 (Fermi-GBM detection: von 
Kienlin, GCN Circ. 16905
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 ; IPN triangulation: Golenetskii et al., GCN 
Circ. 16906
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 ) triggered Konus-Wind at T0=24377.666 s UT (06:46:17.666).

The burst light curve shows a short pulse with
a total duration of ~0.1 s.
The emission is seen up to ~4 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB141011_T24377/

As observed by Konus-Wind, the burst
had a fluence of 1.24(-0.20,+0.02)x10^-6 erg/cm2,
and a 2-ms peak flux, measured from T0-0.012 s,
of 7.1(-1.7,+0.7)x10^-5 erg/cm2/s
(both in the 20 keV - 1.2 MeV energy range).

Modeling the K-W 3-channel time-integrated spectrum
(from T0-0.014 s to T0+0.048 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields
alpha = 0.1(-0.4, +0.4), and
Ep = 521(-75,+120) keV.

All the quoted errors are estimated at the 1 sigma confidence level.
All the quoted values are preliminary.