[vsnet-grb-info 21842] GRB 190306A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23941
SUBJECT: GRB 190306A: Swift-XRT observations
DATE:    19/03/07 17:38:55 GMT
FROM:    Valerio D'Elia at ASDC  <valerio.delia at ssdc.asi.it>

D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 190306A (Shidatsu et al. GCN Circ. 23937) in a series of
observations tiled on the sky. The total exposure time is 1.2 ks,
distributed over 7 tiles; the maximum exposure at a single sky location
was 379 s. The data were collected between T0+24.2 ks and T0+25.6 ks,
and are entirely in Photon Counting (PC) mode. 

No uncatalogued X-ray sources have been detected. The 3-sigma upper
limit in the field (not including the regions where the tiles overlap)
ranges from ~0.05 to ~0.15 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 1.8e-12 to 6.1e-12 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

A previously-catalogued X-ray source has been detected, however because
it is a catalogued object it is unlikely to be the afterglow.

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00078.

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