Discovery of X-rays from the Type IIP supernova ASASSN 16at with Swift
ATel #8588; Dirk Grupe (Morehead State University), Subo Dong (KIAA-PKU), B. J. Shappee (Carnegie Observatories), Tom Holoien, Kris Stanek, Chris Kochanek (Ohio State University), Jose L. Prieto (UDF), & Raffaella Margutti (New York University)
on 25 Jan 2016; 21:31 UT
Credential Certification: Dirk Grupe (firstname.lastname@example.org)
Subjects: X-ray, Supernovae
We report on the discovery of an X-ray source in the galaxy UGC 08041 which is most-likely associated with Type IIP supernova ASASSN-16at (ATEL #8566) with Swift. Up to 2016 January 25, 6 days after the discovery, Swift accumulated 9.6 ks of data. We found a source at RA(2000)=12 55 15.33, Dec(2000)=+00 06 02.2, with an uncertainty of 4.5 arcsec. This position is 3.7 arcsec away from the optical position reported by Bock et al. (ATEL 8655).
The source is detected at a level of (1.69+0.48-0.43)e-3 counts/s (uncertainties determined by the method described by Kraft et al. 1991, ApJ 374, 344), which converts to a flux in the 0.3-10 keV band of (8.45+2.45-2.15)e-17 W/m2. Although the low number of counts does not allow for spectral fitting, a hardness ratio determined from these counts gives a value of HR = (H-S)/(H+S)=0.21+/-0.25 applying the Bayesian method as described in Park et al. (2006, ApJ 652, 610). Here S and H refer to the 0.3-1.0 and 1.0-10 keV energy bands, respectively.
We would like to thank Neil Gehrels for approving our Swift ToOs and the Swift Science Operations Team for performing the observations. We also acknowledge the use of the Swift XRT product tool at the University of Leicester (Evens et al., 2009, MNRAS 397, 1177).