When: December 11, 2017 @1:30-2:30pm
Where: WRF Data Science Studio, The Seminar Room

Strongly Lensed Supernovae

In 1964, Norwegian astronomer Sjur Refsdal showed that time delays between the multiple images of strongly lensed supernovae (LSNe) could be used to measure the Hubble constant (H0). Today, more than 50 years later, only two LSNe have been found. I will describe novel techniques for discovering LSNe that will increase the expected yields of upcoming surveys by ~10x, leading to O(10-20) events from the Zwicky Transient Facility and O(1000) from the Large Synoptic Survey Telescope. This unprecedented sample will enable sub-percent constraints on H0, the value of which is currently in tension at the 3.4 sigma level. I will also describe H0TDOGS (H0 from Time Delay Observations of Gravitationally-lensed Supernovae), a new collaboration dedicated to observing LSNe. I will discuss the effects of microlensing on time delays from Type Ia LSNe, and present a method for controlling them to ~1% precision. Finally, I will show that with the proper computational and observational infrastructure, LSNe can enable exciting new observations—such as shock breakout in strongly lensed Type IIP supernovae—based on predicting the reappearance of lensed images.

Danny Goldstein is a fifth-year graduate student in the Astronomy Department at UC Berkeley. His work focuses on strongly lensed supernovae. You can find his CV here.