A Free-Form Prediction for the Reappearance of Supernova Refsdal in the Hubble Frontier Fields Cluster MACSJ1149.5+2223

TL;DR

This paper improves a free-form lensing method to accurately predict the reappearance of Supernova Refsdal in a galaxy cluster, enabling precise timing and phase predictions for observational follow-up.

Contribution

It extends the free-form lensing technique to include local HII regions, enhancing the accuracy of supernova reappearance predictions in gravitational lensing clusters.

Findings

Predicted the reappearance date of Supernova Refsdal with 7% accuracy.

Estimated the supernova's phase at reappearance, matching its original discovery phase.

Provided a specific coordinate prediction for the supernova's reemergence.

Abstract

The massive cluster MACSJ1149.5+2223(z=0.544) displays five very large lensed images of a well resolved spiral galaxy at $z_{\rm spect}=1.491$. It is within one of these images that the first example of a multiply-lensed supernova has been detected recently as part of the Grism Lens-Amplified Survey from Space. The depth of this data also reveals many HII regions within the lensed spiral galaxy which we identify between the five counter-images. Here we expand the capability of our free-form method to incorporate these HII regions locally, with other reliable lensed galaxies added for a global solution. This improved accuracy allows us to estimate when the Refsdal supernova will appear within the other lensed images of the spiral galaxy to an accuracy of $\sim$ 7\%. We predict this supernova will reappear in one of the counter-images (RA=11:49:36.025, DEC=+22:23:48.11, J2000) and on November 1$^{st}$ 2015 (with an estimated error of $\pm$ 25 days) it will be at the same phase as it was when it was originally discovered, offering a unique opportunity to study the early phases of this supernova and to examine the consistency of the mass model and the cosmological model that have an impact on the time delay prediction.