{
  "circularId": 45930,
  "subject": "GRB 261011A: Swift-BAT refined analysis",
  "eventId": "GRB 261011A",
  "createdOn": 1791851986095,
  "body": "S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha\n(GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss\n(GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T.\nSakamoto (AGU) (i.e. the Swift-BAT team):\n\nUsing the data set from T-179 to T+723 sec from the recent telemetry\ndownlink, we report further analysis of BAT GRB 261011A (trigger #1516664)\n(Cenko et al., GCN Circ. 45896).  The BAT ground-calculated position is\nRA, Dec = 21.911, -21.550 deg which is\n   RA(J2000)  =  01h 27m 38.7s\n   Dec(J2000) = -21d 33' 00.7\"\nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The\npartial coding was 29%.\n\nThe mask-weighted light curve shows a multi-peaked structure that starts\n~T+100 s and ends at ~T+210 s. T90 (15-350 keV) is 78.90 +- 18.49 sec\n(estimated error including systematics). Note that the particularly unusual\nlight curve mentioned in the original circular (Cenko et al., GCN Circ.\n45896) is no longer visible in the ground analysis. Further investigation\nshows that there were some noisy detectors producing coincidental\npulse-like structures around the GRB time, and thus those pulses seen in\nthe raw light curve prior to ~T+100 s are not astrophysical.\n\nThe time-averaged spectrum from T+103.61 to T+208.74 sec is best fit by a\nsimple power-law model.  The power law index of the time-averaged spectrum\nis 1.50 +- 0.07.  The fluence in the 15-150 keV band is 6.3 +- 0.3 x 10^-06\nerg/cm2. The 1-sec peak photon flux measured from T+171.74 sec in the\n15-150 keV band is 3.0 +- 0.4 ph/cm2/sec.  All the quoted errors are at the\n90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttps://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1516664\n",
  "submittedHow": "email",
  "submitter": "Amy <yarleen@gmail.com>"
}