Testing Progenitor Models Using the Late-Time Light Curve of Supernova 1992A

TL;DR

This study uses late-time HST images of supernova SN1992A to measure cobalt isotope ratios, aiming to distinguish progenitor models of Type Ia supernovae, but uncertainties limit definitive conclusions.

Contribution

It provides cobalt isotope ratio measurements for SN1992A and compares them with SN2011fe to test progenitor models using late-time light curves.

Findings

SN2011fe ratio confirmed at 0.026±0.004

SN1992A ratio measured at 0.034±0.010

Uncertainties prevent clear differentiation of progenitor models

Abstract

The dominant radioactive energy source powering Type Ia supernova light curves is expected to switch from the decay of $^{56}$Co to $^{57}$Co at very late epochs. We use archival HST images of SN1992A obtained more than 900 days after explosion to constrain its cobalt isotopic abundance ratio and compare it to the well-studied event SN2011fe. We confirm the $^{57}$Co / $^{56}$Co ratio for SN2011fe of $0.026\pm 0.004$ found by arXiv:1608.01155, consistent with a "double degenerate" progenitor scenario. For SN1992A, we find a ratio of $0.034\pm 0.010$, but the large uncertainty does not allow us to differentiate between progenitor models