# A targeted search for strongly lensed supernovae and expectations for targeted searches in the Rubin era

**Authors:** Peter Craig, Kyle O'Connor, Sukanya Chakrabarti, Steven A. Rodney, Justin R. Pierel, Curtis McCully, Ismael Perez-Fournon  
**arXiv:** [2111.01680](https://arxiv.org/abs/2111.01680)  
**Date:** 2021-11-02  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2111.01680v1/

## Key points

- The study focuses on the detection of gravitationally lensed supernovae (glSNe)
- glSNe are important for time delay cosmology and supernova physics
- The authors present the Las Cumbres Observatory Lensed Supernova Search (LCOLSS), a targeted survey designed to detect glSNe in known strong-lensing systems
- LCOLSS targeted 112 galaxy-galaxy lensing systems with high expected supernova rates based on estimated star formation rates
- No plausible glSN was detected during two years of observing
- The analysis measures the detection efficiency of these observations and performs a Monte Carlo simulation using predicted supernova rates to determine the expected number of glSN detections
- Expected number of detections and 68% Poisson confidence intervals:
- N_SN = 0.20, [0,2.1]
- N_Ia = 0.08, [0,2.0]
- N_CC = 0.12, [0,2.0]
- for all supernovae, Type Ia supernovae and core-collapse (CC) supernovae respectively
- These results align with the absence of any detection in the survey

## Summary

The study focuses on the detection of gravitationally lensed supernovae (glSNe), which are important for time delay cosmology and supernova physics. To address this challenge, the authors present the Las Cumbres Observatory Lensed Supernova Search (LCOLSS), a targeted survey designed to detect glSNe in known strong-lensing systems. Using cadenced $r^\prime$-band imaging, LCOLSS targeted 112 galaxy-galaxy lensing systems with high expected supernova rates based on estimated star formation rates. However, no plausible glSN was detected during two years of observing. The analysis measures the detection efficiency of these observations and performs a Monte Carlo simulation using predicted supernova rates to determine the expected number of glSN detections. The results suggest an expected number of detections and $68\%$ Poisson confidence intervals: $N_{SN} = 0.20, [0,2.1]$, $N_{Ia} = 0.08, [0,2.0]$, $N_{CC} = 0.12, [0,2.0]$ for all supernovae, Type Ia supernovae and core-collapse (CC) supernovae respectively; aligning with the absence of any detection in the survey.