Predicted properties of multiple images of the strongly lensed supernova SN Refsdal

TL;DR

This paper models the gravitational lensing effects of galaxy cluster MACS J1149.6+2223 on supernova SN Refsdal, predicting additional images and their properties to test and refine cluster mass models.

Contribution

It provides the first detailed prediction of multiple images of SN Refsdal, including two previously unobserved images, to improve understanding of cluster mass distribution.

Findings

Six supernova images predicted, including two new images.

One extra image appeared 17 years ago, another in about a year.

Magnification factors range from 4 to 18.

Abstract

We construct a mass model of the cluster MACS J1149.6+2223 to study the expected properties of multiple images of SN Refsdal, the first example of a gravitationally lensed supernova with resolved multiple images recently reported by Kelly et al. We find that the best-fit model predicts six supernova images in total, i.e., two extra images in addition to the observed four Einstein cross supernova images S1--S4. One extra image is predicted to have appeared about 17 years ago, whereas the other extra image is predicted to appear in about one year from the appearance of S1--S4, which is a testable prediction with near future observations. The predicted magnification factors of individual supernova images range from $\sim 18$ for the brightest image to $\sim 4$ for the faint extra images. Confronting these predictions with future observations should provide an unprecedented opportunity to improve our understanding of cluster mass distributions.