Detection of X-Ray Emission from SN 2005ip with Swift
ATel #1004; S. Immler (NASA/USRA/GSFC) and D. Pooley (UC Berkeley) on behalf of the Swift satellite team
on 15 Feb 2007; 07:14 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Stefan Immler (firstname.lastname@example.org)
Subjects: Optical, Ultra-Violet, X-ray, Supernovae
Referred to by ATel #: 1228
Swift Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) started observing the type II SN 2005ip in NGC 2906 (CBET #275, IAUC # 8628 ) on 2007-02-14.08 UT. The following UVOT magnitudes were measured for SN 2005ip: V = 18.5 (747 s exposure time), B = 18.7 (747 s), U = 18.1 (747 s), UVW1 [181-321nm] = 17.7 (1516 s), UVM2 [166-268 nm] = 18.4 (356 s), and UVW2 [112-264 nm] = 18.4 (3000 s). Statistical and systematic errors are approximately 0.1 mag each. The magnitudes have not been corrected for extinction.
An X-ray source is detected at the optical/UV position of SN 2005ip at a 5.9-sigma level of confidence in the merged 8.9 ks Swift XRT observation obtained simultaneously with the UVOT. The XRT net count rate is (5.4+/-0.9) E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux of (1.5+/-0.3) E-13 ergs/cm/cm/s and a luminosity of (1.6+-/0.3) E40 ergs/s for an adopted thermal plasma spectrum with a temperature of kT = 1 keV typical for the late X-ray emission of SNe, a Galactic foreground column density of N_H = 3.7E+20 (Dickey & Lockman, 1990, ARAA 28, 215) and a distance of 30 Mpc (z = 0.007138, De Vaucouleurs et al. 1991, Third Reference Catalogue of Bright Galaxies, v3.9; Ho = 71, O_M = 1/3, O_L = 2/3). No X-ray source is seen at the position of the nucleus of the host galaxy NGC 2906 (offset 15 arcsec). The high X-ray luminosity of SN 2005ip is similar to those of type IIn SNe at late times, such as SNe 1988Z, 1995N, and 1998S.