[vsnet-grb-info 13595] GRB 130603B: First epoch of XMM-Newton observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14922
SUBJECT: GRB 130603B: First epoch of XMM-Newton observations
DATE:    13/06/25 01:10:04 GMT
FROM:    Wen-fai Fong at CFA  <wfong at cfa.harvard.edu>

W. Fong, G. Migliori, R. Margutti, and E. Berger (Harvard) report:

"We observed the short-duration GRB 130603B (Melandri et al., GCN 14735)
with XMM-Newton + EPIC-pn starting on 2013 June 06.22 UT (2.57 d after the
burst) for a total of 24 ksec. We clearly detect the X-ray afterglow at the
position of the enhanced XRT error circle (Evans et al., GCN 14739) at a
significance level of about 6-sigma.

Taken together with the Swift/XRT afterglow light curve for t>4000 sec
(Kennea et al., GCN 14749), these observations indicate a single power-law
decline with index alpha_X=-1.83+/-0.15.  Therefore, the XMM observations
rule out the presence of a break at  t~4000 sec to 2.57 d, in contrast to
the suggested X-ray and optical break at ~8 hr (Tanvir et al., arXiv:
1306.4971)."