V. Mangano, V. La Parola, E. Troja, G. Cusumano,
T. Mineo (INAF-IASFPA), A. Parsons (GSFC), J. Kennea (PSU)
on behalf of the Swift-XRT team
We have analyzed the first two orbits of data of GRB060614
(Parsons et al 2006, GCN 5252).
The XRT data set consists of 370 s exposure in Windowed
Timing (WT) in the first orbit followed by 2.1 ks exposure
in Photon Counting (PC) mode in the second orbit.
The refined position of the source is
RA (2000) = 21h 23m 32.00s
Dec (2000) = -53d 01' 39.4"
with an uncertainty of 3.7 arcsec (90% containment).
This position is 7.7 arcsec from the on board
XRT position, 3.5 arcsec from the UVOT afterglow
position and 51.7 arcsec from the BAT position
(Parsons et al. 2006, GCN 5252).
The 0.2-10 keV X-ray light curve shows an
exponential decay with a characteristic decay time
of 75 s during all the first orbit, and a nearly
flat behaviour at the level of 0.2 counts/s during
the second orbit that starts 4500 s after the trigger.
The WT light curve is highly piled-up, with an initial
(corrected) count rate of about 1300 counts/s.
From the present data we cannot give any reliable prediction
for the light curve evolution in the next hours. Further
data will be avaliable after the end of the Malidi gap
(2006 June 15, 1:27 UT).
The WT data show strong spectral evolution with time,
with an average photon index of 1.65 +/- 0.04 in the
time interval 90-270 s from the trigger and an
average photon index of 2.95 +/- 0.11 in the time
interval 270-460 s. WT spectra show evidence of
absorption at the level of (1.3 +/- 0.3)e21 cm^-2,
in excess with respect to the Galactic N_H of 3.e20 cm^-2.
The PC spectrum extracted from the second orbit of data
is well fitted by an absorbed power law with photon index
1.8 +/- 0.2 and N_H consistent with the Galactic value.
The average 0.2-10 keV unabsorbed flux during the
second orbit is 9.3e-12 erg cm^-2 s^-1.
This Circular is an official product of the Swift XRT Team.