[vsnet-grb-info 17684] GRB160228A: Further analyses on spectral lag and extended emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19121
SUBJECT: GRB160228A: Further analyses on spectral lag and extended emission
DATE:    16/02/29 20:21:35 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien at nasa.gov>

J. P. Norris (BSU), S. D. Barthelmy (GSFC), A. Y. Lien (GSFC/UMBC),
N. Gehrels (GSFC), D. Malesani (DARK/NBI), T. Sakamoto (AGU),
and E. Troja (GSFC/UMCP) report:

We report on the spectral lag analysis of the initial pulse and extended
emission measurements of GRB 160228A (Malesani et al., GCN Circ. 19107).

Using a 32-ms binned light curve (which is the shortest time bin
possible for the lag analysis in this case), the lag of the initial pulse
(~T0 to ~T0+2 s) for the 100-350 keV to 25-50 keV bands is estimated
as 75 (+100/-60) ms (with 1-sigma error).

Despite the large error bars, the lag is inconsistent with zero, and thus
the lag of the initial pulse is much more consistent with those from a long
GRBs rather than short bursts (e.g., Norris et al. 2006).

Moreover, further analysis of the initial pulse intensity shows that it is
only a factor of several more intense than the extended emission in
both the 1-s binned and 32-ms binned light curves, which is much less
prominent than the usual short GRBs with extended emission (e.g.,
Norris et al. 2006).