Type: Talk
Session: Transient and Variable Star Science I
Author: Prajakta Mane

Abstract: Gravitationally lensed type Ia supernovae (SNe Ia) are uniquely suited to infer the Hubble constant, an important problem in cosmology. In addition to obtaining accurate time delays, the standard candle nature of SNe Ia also provides additional constraints on the model of the lensing object. Finding such supernovae in the ground-based imaging data from the upcoming Vera Rubin Observatory is a challenge. The multiply lensed images of a SN Ia can be identified as newly appearing sources in difference imaging. However, these images are expected to be unresolved for a majority of the systems. We use the Rubin science pipelines' difference imaging (DI) module and devise the strategy to identify such lensed supernovae. In our preliminary results, the employed DI pipeline recovers about 70% of lensed SNe Ia injected in the real imaging data from the Hyper-Suprime Cam Survey, a precursor to Rubin LSST. We also investigate and assess the suitability of the color-magnitude diagram (Quimby et al. 2014) as a rapid diagnostic tool for screening genuine (un-)resolved lensed SNe Ia. We find that the color-magnitude space can help identify promising lensed SNe Ia regardless of if we catch the supernovae during the rising or the falling part of their light curve. The contamination from the core-collapse supernovae is found to not be too high. We also look at variations in the applicable color-magnitude criteria with respect to different source redshift bins and present comparison with the real populations of type Ia and core-collapse supernovae.