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GCN Circular 19974

Subject
GRB 161001A, Swift-BAT refined analysis (likely a short GRB)
Date
2016-10-01T16:29:32Z (8 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),

J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),

H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),

J. P. Norris (BSU), K. L. Page (U Leicester)

D. M. Palmer (LANL), T. Sakamoto (AGU),

M. Stamatikos (OSU), T. N. Ukwatta (LANL)

(i.e. the Swift-BAT team):


Using the data set from T-274 to T+962 sec from the recent telemetry downlink,

we report further analysis of BAT GRB 161001A (trigger #714404)

(Page, et al. GCN Circ. 19967Not found
 
 
).  The BAT ground-calculated position is

RA, Dec = 71.923, -57.261 deg which is

  RA(J2000)  =  04h 47m 41.5s

  Dec(J2000) = -57d 15' 39.8"

with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).

The partial coding was 78%.


The mask-weighted light curve shows several overlapping pulses

that stars at ~T-0.3, and ends at ~T+3 s. The highest peak occurs at

~ T+1.6 s. T90 (15-350 keV) is 2.6 +- 0.4 sec (estimated error including

systematics).


The time-averaged spectrum from T-0.2 to T+3.1 sec is best fit by a simple

power-law model.  The power law index of the time-averaged spectrum is

1.14 +- 0.09.  The fluence in the 15-150 keV band is 6.7 +- 0.4 x 10^-7 erg/cm2.

The 1-sec peak photon flux measured from T+1.40 sec in the 15-150 keV band

is 3.5 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence

level.


Using a 16-ms binned light curve, the lag analysis finds a lag of

7 (+/- 13) ms for the 100-350 keV to 25-50 keV band, and -7.5 (+26, -19) ms

for the 50-100 keV to 15-25 keV band, which is consistent with

those of a short GRB.


The results of the batgrbproduct analysis are available at

http://gcn.gsfc.nasa.gov/notices_s/714404/BA/