Speaker: Steve Lawrence (Hofstra University)

Host: Charlotte Wood

Title: Reflections of a Violent Past: Light echoes from Supernova 2016adj in the Dust Lane of Centaurus A.

Abstract: The bright galaxy Centaurus A (NGC 5128) is remarkable for being one of the closest examples of a giant elliptical, an AGN and a radio galaxy. Despite being a giant elliptical, it has massive dust lanes and recent star formation, making it the poster child for the theory of galactic cannibalism. In February 2016, a significantly-reddened core-collapse supernova, SN 2016adj, was discovered in the dust lane, prompting us to begin following it with the Hubble Space Telescope to search for light echoes.  I will present a multi-band sequence of HST difference imaging documenting the emergence and evolution of multiple light echoes spanning +34 to +1991 days past the epoch of B-band maximum.  I will discuss the geometry and distribution of four echoing dust sheets detected by our program and review our plans to characterize the grain properties of the dust from the cannibalized galaxy.