Swift Observations of SN 2007C
ATel #976; S. Immler (NASA/USRA/GSFC) and P. J. Brown (PSU) on behalf of the Swift satellite team
on 15 Jan 2007; 19:18 UT
Credential Certification: Stefan Immler (firstname.lastname@example.org)
Subjects: Optical, Ultra-Violet, X-ray, Supernovae
Swift Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) started observing the type Ib SN 2007C (CBET #798, CBET #800, ATel #975) on 2007-01-13.3 UT and 2007-01-15.0 UT. The following UVOT magnitudes and upper limits (3-sigma) were measured for these two epochs: V = 15.9, 15.8, (483 s and 447 s exposure times), B = 17.1, 17.2 (483 s, 447 s), U = 18.1, 18.4 (483 s, 447 s), UVW1 [181-321nm] > 19.5, 19.5 (966 s, 896 s), UVM2 [166-268 nm] > 19.7, 19.6 (1329 s, 1226 s), and UVW2 [112-264 nm] > 20.2, 20.1 (1938 s, 1796 s). Statistical errors are 0.2 mag and systematic errors are 0.1. The magnitudes have not been corrected for extinction.
No X-ray source is detected at the position of the SN in the merged 6.9 ks XRT observation obtained simultaneously. The 3-sigma upper limit to the XRT net count rate is 2.7 E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux and luminosity of < 1.4 E-13 ergs/cm/cm/s and < 9.2 E39 ergs/s, respectively, for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of N_H = 2.61E+20 (Dickey & Lockman, 1990, ARAA 28, p215) and a distance of 23.7 Mpc (z=0.005604, NED; H_o = 71 km/s/Mpc, Omega_M = 1/3, Omega_L = 2/3).