HSTbanner

AR 15050 (Archival Research)

Sun Jul 14 03:42:11 GMT 2024

Principal Investigator: Justin Pierel
PI Institution: Space Telescope Science Institute
Investigators (xml)

Title: Turning Gravitationally Lensed Supernovae into Cosmological Probes
Cycle: 25

Abstract
Recent HST observations have been critically important for two landmark discoveries of gravitationally lensed supernovae: the first multiply-imaged SN, "Refsdal", and the first Type Ia SN resolved into multiple images, SN iPTF16geu. Fitting the multiple light curves of such objects can deliver measurements of the lensing time delays, which in turn provide precise tests of lens models or unique constraints on the Hubble constant and other cosmological parameters. For both of these SNe, initial constraints on the time delays have been limited by the need to account for subtle microlensing effects. We will perform a complete reanalysis of both SN Refsdal and SN iPTF16geu, in order to refine estimates of their lensing magnifications and time delays. Our work will improve upon previous efforts by revising the data processing and photometry, and including the significant yet previously ignored effects of microlensing. Additionally, we will develop a publicly available software package in the course of this work, optimized specifically for multiply-imaged SNe. This software will be an important tool in the next decade, supporting precise time delay measurements of tens to hundreds of lensed SNe to be found with LSST and WFIRST.