TITLE:   GCN CIRCULAR
NUMBER:  18672
SUBJECT: GRB 151205B: further Swift-XRT observations
DATE:    15/12/06 23:59:28 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, A. Melandri (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti
(INAF-OAB/PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester),
C. Pagani (U. Leicester), A. Maselli  (INAF-IASFPA), F. E. Marshall
(NASA/GSFC) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

We have analysed 3.3 ks of Photon Counting (PC) mode XRT data for the
Swift/BAT-detected burst GRB 151205B (Marshall et al. GCN Circ. 18659),
collected between T0+3.1 ks and T0+68.9 ks. 

The first set of observations consists of 1.0 ks of data collected 
between T0+3.1 ks and T0+5.7 ks. 
No X-ray sources have been detected inside or close to the Swift/BAT
error region. The 3-sigma upper limit in the field is 7.7e-3 ct  s^-1,
corresponding to a 0.3-10 keV observed flux of 2.7e-13 erg cm^-2 s^-1
(assuming a typical GRB spectrum).

The second set of observations consists of 2.3 ks data collected 
between T0+39.8 ks and T0+68.9 ks. 
No X-ray sources have been detected inside or close to the Swift/BAT
error region. The 3-sigma upper limit in the field is 3.7e-3 ct  s^-1,
corresponding to a 0.3-10 keV observed flux of 1.3e-13 erg cm^-2 s^-1
(assuming a typical GRB spectrum).


The results of the XRT-team automatic analysis of the XRT observations,
including a position specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00666378.

This circular is an official product of the Swift-XRT team.