Swift XRT Detection of Supernova 2008M in X-Rays
ATel #2478; S. Immler (NASA/CRESST/GSFC), on behalf of the Swift satellite team
on 15 Mar 2010; 21:33 UT
Credential Certification: Stefan Immler (firstname.lastname@example.org)
Subjects: X-ray, Supernovae
Using 10.1 ks of Swift X-Ray Telescope (XRT) observations of the Type II SN 2008M in ESO 121-026 (CBET #1214), obtained between 2008-01-28 and 2008-01-30, an X-ray point-source is detected at the position of the SN with a 3-sigma significance of source detection. The PSF, dead-time, and vignetting corrected XRT net count rate is (1.1+/-0.4)E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux of (5.5+/-1.9)E-14 erg/cm/cm/s and a luminosity of (8.8+/-3.0)E39 erg/s for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of N_H = 4.7E+20 (Dickey & Lockman, 1990, ARAA 28) and a distance of 36.6 Mpc (Terry, Paturel & Ekholm, 2002, A&A 393, 57).
No X-ray source is visible at this position in Swift XRT observations obtained between 2008-02-01 and 2008-02-05 (15.1 ks exposure time) down to a 3-sigma limiting flux and luminosity of <4.5E-14 erg/cm/cm/s and 7.2E39 erg, and in observations obtained between 2009-12-10 and 2010-02-14 (57.5 ks exposure time) down to a 3-sigma limiting flux and luminosity of <1.3E-14 erg/cm/cm/s and 2.1E39 erg/s, respectively.
Due to the positional coincidence and fading of the X-ray source, it is likely that the X-rays arise from the interaction of the SN shock with circumstellar material from a strong stellar wind of the progenitor.
Swift XRT Images of SN 2008M