1. Discovery of peculiar X-ray characteristics of AT2018cow with Swift
Liliana Rivera Sandoval
Collaborators:
Tom Maccarone (TTU)
Alessandra Corsi (TTU)
Peter Brown (Texas A&M)
David Pooley (Trinity University)
Craig Wheeler (UT-Austin)
Artistic impression of a super luminous supernova, NASA

2. NASA’s Goddard Space Flight Center

3. AT2018cow Swift trigger Day 0 ATLAS Discovery
Accreting white dwarf
Day ATLAS Discovery
Day Swift observations: very blue object, X-ray bright
Companion
star
Discovery: 16 June 2018
Swift optical
Swift UV
First Swift data: 19 June 2018

4. The Discovery of X-ray Variability
Some optical spectra —> Core collapse Supernovae
Interaction between the supernova ejecta and a non-uniform circum-stellar medium —> X-rays spikes
Massive stars eject large
amounts of mass
Rivera Sandoval et al., 2018
AT2018cow location: spiral arm of star forming galaxy
Credit: NASA, ESA, and the Hubble SM4 ERO Team

5. No significant spectral evolution in low energy (0.3-10 keV) X-rays
X-ray Spectra
Spectral evolution
X-ray spectrum
No significant spectral evolution in low energy ( keV) X-rays
Rivera Sandoval et al., 2018

6. Contact: Liliana Rivera Sandoval, liliana.rivera@ttu.edu
Take-Home Message
Our early and extensive observations with Swift played an important role in the study of Fast Evolving Luminous Transients —> discovery of unprecedented characteristics.
AT2018cow was a very blue, X-ray bright and fast-rise time transient.
We discovered its peculiar X-ray luminosity variability.
The low energy X-ray spectrum did not significantly change.
Supernova ejecta + non-uniform circum-stellar medium may explain the Swift X-ray results.
Contact: Liliana Rivera Sandoval,