Carnegie Mellon University

Astro Seminar

Rage against the dying of the light: Type Ia supernovae at >1000 days

Type Ia supernovae have famously been used as standard candles, a use that led to the discovery that the expansion of the Universe was accelerating under the influence of a mysterious new phenomenon called "dark energy." And yet, we still do not have a clear picture of their progenitors, i.e., what types of star systems end up exploding as Type Ia supernovae. Most observers study these supernovae when they are young and at their brightest. In my talk, I will describe the various physical processes that produce the light we receive from Type Ia supernovae, present recent results from Hubble Space Telescope observations of nearby Type Ia supernovae taken hundreds of days after explosion, and show how these so-called "late-time" observations reveal a possible new correlation between the intrinsic luminosity of the supernovae and the way their brightness fades at these late times. If confirmed, this correlation could provide a brand new diagnostic of Type Ia supernova progenitor, explosion, and nebular physics.