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GCN Circular 28845

GRB 201105A: Swift detected burst and BAT refined analysis
2020-11-06T01:13:41Z (3 years ago)
Amy Lien at GSFC <>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
N. J. Klingler (PSU), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), K. K. Simpson (PSU),
M. Stamatikos (OSU),T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

At 2020-11-05 05:31:10 UT, the Swift Burst Alert Telescope (BAT)
triggered and located GRB 201105A (trigger=1004239).
The burst occurred during GCN downtime, and the initial
circular (Simpson et al.) may have been lost.
We thus include information from that circular here as well.

The GRB location is Sun-constrained until 2020-12-27,
so no XRT or UVOT data are available.

Using the data set from T-239 to T+963 sec from the recent
telemetry downlink, the BAT ground-calculated position is
RA, Dec = 245.610, 12.734 deg which is
   RA(J2000)  =  16h 22m 26.4s
   Dec(J2000) = +12d 44' 03.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%

The BAT mask-weighted light curve shows a FRED-like pulse that starts
at ~T-3 s and peaks at ~T+1 s. The main structure ends at ~T+40 s,
with a tail emission that lasts till ~T+100 s. T90 (15-350 keV)
is 33.82 +- 4.03 sec (estimated error including systematics).

The time-averaged BAT spectrum from T-2.85 to T+72.11 sec is best
fit by a simple power-law model.  The power law index of the
time-averaged spectrum is 1.08 +- 0.03.  The fluence in the
15-150 keV band is 1.2 +- 0.02 x 10^-5 erg/cm2. The 1-sec peak
photon flux measured from T+0.76 sec in the 15-150 keV band is
13.9 +- 0.5 ph/cm2/sec.  All the quoted errors are at
the 90% confidence level.

The results of the batgrbproduct analysis are available at

Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 AT 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:
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