Swift/XRT monitoring of SN2011dh: evidence for fading
ATel #3420; R. Margutti, A. Soderberg (Harvard University)
on 9 Jun 2011; 20:38 UT
Credential Certification: Raffaella Margutti (firstname.lastname@example.org)
Subjects: X-ray, Supernovae
We have analyzed 24 ks of Swift/XRT data of SN1011dh (Silverman
et al. 2001, Atel #3398; Reiland et al. 2011, CBET #2736)
collected in the time period June 3-7. In agreement with
Campana & Burrows (2011, Atel #3414) we find that the source is
detected at an average level of ~6 E-03 c/s.
We furthermore find that the source has faded from ~1.3 E-02 c/s
to ~3 E-03 c/s, with a power-law decay index of alpha~ -1.8 (+0.6,-0.6
90% c.l.) The probability of a chance fluctuation is below 0.01%
(binomial test), thus we conclude that the observed decay
is statistically significant.