Swift follow-up observations of the optical transient AT2018cow/ATLAS18qqn - update
ATel #11739; L. E. Rivera Sandoval, T. Maccarone (Texas Tech University)
on 20 Jun 2018; 14:33 UT
Credential Certification: Liliana Rivera Sandoval (liliana.rivera@ttu.edu)
Subjects: Optical, Ultra-Violet, X-ray, Transient
Using the ~0.9ks Swift observations (from 2018-06-19T10:34:53 to 2018-06-19T13:38:52) of the optical transient AT2018cow/ATLAS18qqn, we have fitted an absorbed power law model using wilm abundances (Wilms et al. 2000) and VERN cross-sections (Verner et al. 1996) to the X-ray spectrum and obtained the following values nh = 5.2 +/- 4.7 E20 cm2, photon index 1.6 +/- 0.1 and flux 2.6 +/- 0.3 E-11 erg/cm2/s in the 0.3-10 keV band. In Atel #11737, where we reported on ~0.5 ks Swift observations, the reported error in nh should be 8.0 instead of 0.08. Errors are at 90% confidence interval.
We thank the Swift team for approving and executing our ToO.