X-ray Swift observations of SN 2018cow

TL;DR

This paper reports on Swift X-ray observations of SN 2018cow, revealing variable X-ray emission likely caused by interaction with a non-uniform circumstellar medium, providing insights into the progenitor's environment.

Contribution

First detailed analysis of Swift X-ray data showing variability and potential circumstellar interaction in SN 2018cow.

Findings

Detected X-ray variability on timescales of days.

Evidence suggests interaction with a non-uniform circumstellar medium.

Supports the idea of a luminous-blue-variable-like progenitor.

Abstract

Supernova (SN) 2018cow (or AT2018cow) is an optical transient detected in the galaxy CGCG 137-068. It has been classified as a SN due to various characteristics in its optical spectra. The transient is also a bright X-ray source. We present results of the analysis of ~62ks of X-ray observations taken with the Neil Gehrels Swift Observatory over 27 days. We found a variable behavior in the 0.3-10 keV X-ray light curve of SN 2018cow, with variability timescales of days. The observed X-ray variability could be due to the interaction between the SN ejecta and a non-uniform circumstellar medium, perhaps related to previous mass ejections from a luminous-blue-variable-like progenitor.