Gamma-ray Burst 140529A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #16340
  J. R. Cummings on behalf of the Swift-BAT science team
  At 09:28:06 the IPN detected GRB 140529A. Swift was slewing at this time. A mosaic of images from BAT event data shows a very strong detection at RA, Dec 228.816, -41.044, which is

  RA (J2000)   15h 15m 15.8s 	
  Dec (J2000) -41d 02' 39"
  
  with an estimated 90% uncertainty radius of 1.5 arcmin.
  
  
  The burst consisted of a single FRED peak about 5 seconds long.  The maximum
  count rate in BAT was about 5000 counts/sec.
  
  
  A Swift TOO has been requested.
  
   GCN Circular #16342 
  
  
  P.A. Evans (U. Leicester) and J.L. Racusin (GSFC) report on behalf of
  the Swift-XRT team:
  
  
  We have analysed 2.5 ks of XRT data for the ground-detected GRB 140529A
  (Cummings, GCN. Circ. 16340) from 65.0 ks to 75.4 ks after the BAT
  trigger time. The data are entirely in Photon Counting (PC) mode.  An
  X-ray source is detected within the Swift/BAT error circle. Using 1098
  s of PC mode data and 1 UVOT image, we find an enhanced XRT position
  (using the XRT-UVOT alignment and matching UVOT field sources to the
  USNO-B1 catalogue): RA, Dec = 228.78202, -41.05295 which is equivalent
  to:
  RA (J2000): 15h 15m 07.68s
  Dec(J2000): -41d 03' 10.6"
  
  with an uncertainty of 3.3 arcsec (radius, 90% confidence). This
  position is 97 arcsec from the Swift/BAT position. 
  
  
  In the first two spacecraft orbits, totalling 1.2 ks of data, the
  source is present with a count rate of 0.012+/-0.004 ct/sec. In the
  final orbit, with 1.3 ks of data the source is not detected, with a
  3-sigma upper limit of 0.0045 ct/sec. We thus conclude that this was
  the afterglow of GRB 140529A.
  
  
  The results of the XRT-team automatic analysis are available at
  http://www.swift.ac.uk/xrt_products/00020383.
  
  
  This circular is an official product of the Swift-XRT team.
  
   GCN Circular #16343 
  
  
  S. R. Oates (IAA-CSIC, MSSL-UCL) and J.L. Racusin (GSFC) 
  report on behalf of the Swift/UVOT team:
  
  
  The Swift/UVOT began settled observations of the field of the ground-detected 
  GRB 140529A 65ks after the BAT trigger (Cummings, GCN. Circ. 16340).
  No optical afterglow consistent with the XRT position 
  (Evans et al., GCN Circ. 16342) 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 initial exposures are:
  Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
  
  white             65040       69412          287         >21.0
  u                 65017       74873         1635         >21.0
  
  The magnitudes in the table are not corrected for the Galactic extinction
  due to the reddening of E(B-V) = 0.13 in the direction of the burst
  (Schlegel et al. 1998).
  
   GCN Circular #16345 
  
  
  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, soft spectrum GRB 140529A (Cummings, GCN 16340)
  triggered Konus-Wind at T0=34086.312 s UT (09:28:06.312).
  The burst light curve shows a single peak with a total duration of ~3 s.
  The emission is seen up to ~1 MeV.
  
  
  As observed by Konus-Wind, the burst had a fluence of 
  2.6(-0.3,+0.3)x10^-6 erg/cm2,
  and a 64-ms peak flux, measured from T0+0.248 s, of 1.7(-0.4,+0.4)x10^-6 
  erg/cm2/s
  (both in the 20 keV - 10 MeV energy range).
  
  
  The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s)
  is best fit in the 20 keV - 1 MeV range
  by a power law with exponential cutoff model:
  dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
  with  alpha = -1.50(-0.45,+0.54),
  and Ep = 52(-31,+17) keV, chi2 = 66/50 dof.
  Fitting by a GRB (Band) model yields the same alpha and Ep,
  and an upper limit on the high energy photon index: beta < -2.92 (chi2 = 
  66/49 dof).
  
  
  The Konus-Wind light curve of this GRB is available at
  http://www.ioffe.ru/LEA/GRBs/GRB140529_T34086/
  
  
  All the quoted errors are at the 90% confidence level.
  All the quoted values are preliminary.
  
   GCN Circular #16346 
  
  
  J. R. Cummings, S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
  N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
  C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
  M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
  (i.e. the Swift-BAT team):
  
  
  We report further analysis of GRB 140529A (Cummings, GCN Circ. #16340). The
  best BAT position is RA, Dec 228.810,-41.042 which is
  RA (J2000)    15h 15m 14.4s
  Dec (J2000)  -41d 02' 33"
  
  with an estimated 90% uncertainty radius of 1.2 arcmin.  This is 16 arcsec
  from the previously reported BAT position and 85 arcsec from the position of
  the XRT source reported in Evans et al. (GCN Circ #16342).  The partial coding
  was about 18%.
  
  
  The maskweighted lightcurve shows a single FRED peak with an estimated T90
  of 4.5 +- 0.5 seconds.
  
  
  The best fit to the spectrum from 15-150 keV is a powerlaw with an exponential
  cutoff.  The photon index is 0.85 +- 0.35 with a cutoff energy of 75 +- 10 keV.
  The best simple powerlaw fit has a photon index of 1.66 +- 0.08.  The total
  fluence from 15-150 keV in5.0 seconds was (2.2 +- 0.1) x 10^-6 ergs/cm^2.  The
  1-second peak flux in the energy range 15-150 keV was 11.5 +- 0.7 photons/cm^2.
  
  
  Because this was not a normal onboard trigger, the usual automated BAT data
  products are not available.