CANCELLED

Special Astrophysics Seminar

RAISIN: Type IA SN in the Near-IR

Robert P. Kirshner

Chief Program Officer, Gordon and Betty Moore Foundation
Clowes Research Professor of Science, Harvard University

Twenty years ago, tracing the history of cosmic expansion with type Ia supernovae led to the surprising discovery of cosmic acceleration. Since then, the size of supernova samples at all redshifts has grown so that systematic errors, not statistical ones, limit our knowledge of dark energy. Observations of supernovae in the near infrared are less vulnerable to systematic errors introduced by dust extinction and empirical evidence shows they are also better stand candles when observed in the rest-frame infrared. I will describe a sample of SN Ia discovered by Pan-STARRS and by Dark Energy Survey that were followed up in the rest-frame infrared with the Hubble Space Telescope. This “RAISIN” sample is small enough that statistical errors dominate, but it presages the very large near-infrared supernova sample that will be observed with WFIRST.