TITLE:   GCN CIRCULAR
NUMBER:  9385
SUBJECT: GRB 090515: Swift/BAT spectral lag results
DATE:    09/05/17 19:35:45 GMT
FROM:    Tilan Ukwatta at GSFC/GWU  <tilan.ukwatta@gmail.com>

T. N. Ukwatta (GWU/GSFC), J. Norris (U. Denver), N. Gehrels (GSFC),
S. D. Barthelmy (GSFC) (for the Swift-BAT team):

For GRB 090515 (Beardmore et al. GCN 9356), the BAT team has analyzed
spectral lags for the data from T-0.05 sec to T+0.1 sec using non-mask
weighted light curves with 1 msec time binning. The spectral lags
were measured between standard canonical BAT energy bands: channel 1
(15-25 keV), 2 (25-50 keV), 3 (50-100 keV) and 4 (100-350 keV) are
given below.

Lag Ch3-Ch1 : 3.9 (+2.4, -2.1) msec
Lag Ch3-Ch2 : 3.0 (+1.0, -1.0) msec
Lag Ch4-Ch2 : 2.8 (+1.1, -1.4) msec
Lag Ch4-Ch3 : 1.0 (+1.0, -1.0) msec

Furthermore, Bayesian block analysis, on the light curve time range
from T+10 sec to T+230, yields that there is no apparent
extended emission for this burst.