Explosions of blue supergiants from binary mergers for SN 1987A

TL;DR

This study models blue supergiant explosions from binary mergers to better explain the light curves of SN 1987A and similar supernovae, showing improved fits over single star models and highlighting the impact of progenitor properties.

Contribution

It introduces binary merger progenitor models for blue supergiant supernovae, providing better fits to observed light curves than previous single star models.

Findings

Merger models fit SN 1987A light curve better than single star models.

Best-fit merger model for SN 1987A has a radius of 37 solar radii and ejecta mass of 20.6 solar masses.

Different progenitor parameters are needed for SN 2006V, indicating diversity in supernova progenitors.

Abstract

Based on the work of Menon & Heger (2017), we present the bolometric light curvesand spectra of the explosions of blue supergiant progenitors from binary mergers. We study SN 1987A and two other peculiar Type IIP supernovae: SN 1998A and SN 2006V. The progenitor models were produced using the stellar evolution code Keplerand then exploded using the 1D radiation hydrodynamic code Crab. The explosions of binary merger models exhibit an overall better fit to the light curve of SN 1987A than previous single star models, because of their lower helium-core masses, larger envelope masses, and smaller radii. The merger model that best matches the observational constraints of the progenitor of SN 1987A and the light curve is a model with a radius of 37 solar radii, an ejecta mass of 20.6 solar masses, an explosion energy of 1.7 Bethe, a nickel mass of 0.073 solar masses, and a nickel mixing velocity of 3,000 km/s. This model also works for SN 1998A and is comparable with earlier estimates from semi-analytic models. In the case of SN 2006V, however, a model with a radius of 150 solar radii and ejecta mass of 19.1 solar masses matches the light curve. These parameters are significantly higher than predictions from semi-analytic models for the progenitor of this supernova.