GRB 201105A

B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
626247072 at 05:31:07 on 05 Nov. 2020 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 247.4+/-0.4 deg
Decl.(2000.0) = 12.6+/-0.5 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB201105230/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB201105230/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB201105230/json

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
http://gcn.gsfc.nasa.gov/notices_s/1004239/BA/

Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 AT
gmail.com). 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: http://www.swift.psu.edu/)

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 201105A
(Fermi-GBM detection: Biltzinger et al., GCN Circ. 28842
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 ,
Bissaldi & Lesage, GCN Circ. 28843
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 ;
Swift-BAT trigger #1004239: Markwardt et al., GCN Circ. 28845
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 )
triggered Konus-Wind at T0=19865.464 s UT (05:31:05.464).

The burst light curve shows a single FRED-like pulse
which starts at ~T0-2.4 s and has a total duration of ~29.6 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/GRB201105_T19865/

As observed by Konus-Wind, the burst
had a fluence of 7.88(-0.85,+0.79)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.624 s,
of 1.59(-0.30,+0.30)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+26.368 s)
is best fit in the 20 keV - 4 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.55(-0.12,+0.13),
the high energy photon index beta = -2.11(-0.17,+0.11),
the peak energy Ep = 286(-31,+42) keV
(chi2 = 92/71 dof).

The spectrum near the maximum count rate
(measured from T0+2.304 to T0+4.096 s)
is best fit in the 20 keV - 4 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.43(-0.18,+0.20),
the high energy photon index beta = -2.05(-0.18,+0.12),
the peak energy Ep = 305(-48,+66) keV
(chi2 = 51/60 dof).

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