[vsnet-grb-info 2933] GRB060213: Swift XRT observations and possible afterglow candidate

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4770
SUBJECT: GRB060213:  Swift XRT observations and possible  afterglow candidate
DATE:    06/02/17 18:53:47 GMT
FROM:    David Morris at PSU/Swift-XRT  <morris at astro.psu.edu>

D. C. Morris (PSU), J. A. Kennea (PSU), C. Pagani (PSU) report on behalf 
of the Swift XRT Team:

Swift responded to the IPN trigger of GRB060213 (Pal'shin et al., GCN 
4762) and has observed the entire IPN error polygon with the XRT during 
observations spanning T+174ks to T+285ks. We have analyzed the entire 
XRT ground-linked dataset. In 9ks of data we find a single, faint, 
uncatalogued source within the IPN localization at the following position:

RA(J2000): 09 26 24.5
Dec(J2000): -09 06 58.5

with an estimated uncertainty of 10 arcseconds (90% containment). The 
source is detected at 2.6 sigma and the flux at T+3days from the 
GRB060213 trigger is 2e-13+/-5e-14 ergs/cm2/s. We note that this source 
does not show evidence of fading during the 1.25 day window of XRT 
observations and appears slightly extended to the east, which both 
suggest the possibility that it may be a faint serendipitous object and 
not the GRB afterglow. However, we also note that it is not uncommon for 
a GRB afterglow at this late stage to have a fairly flat lightcurve 
consistent with the observed counting statistics, and we therefore 
cannot rule this out as an afterglow candidate.  Further observations 
will be required to determine conclusively whether this source is fading.

No other point source is detected above a limiting flux of 1e-13 
ergs/cm2/s anywhere in the IPN localization, or in the broader 
surrounding region covered by the XRT field of view during the 
observations.

No further observations are planned for at least the next four days; 
however, we tentatively plan further observations in approximately a 
week to determine whether the source is fading.

The XRT image of the field can be viewed at 
http://www.swift.psu.edu/images/GRB060213.jpg

This circular is an official product of the Swift XRT Team.