The Type IIb Supernova 2011dh from a Supergiant Progenitor

TL;DR

This study uses hydrodynamical models to analyze SN 2011dh, indicating a large yellow supergiant progenitor with specific mass and energy parameters, challenging single-star evolutionary scenarios.

Contribution

The paper provides detailed hydrodynamical modeling of SN 2011dh's progenitor, constraining its properties and ruling out certain massive progenitors, thus offering new insights into its origin.

Findings

Progenitor was a large yellow supergiant with R ~200 Rsun.

Ejecta mass approximately 2 Msun and explosion energy 6-10 x 10^50 erg.

Progenitor's main sequence mass estimated between 12-15 Msun.

Abstract

A set of hydrodynamical models based on stellar evolutionary progenitors is used to study the nature of SN 2011dh. Our modeling suggests that a large progenitor star ---with R ~200 Rsun---, is needed to reproduce the early light curve of SN 2011dh. This is consistent with the suggestion that the yellow super-giant star detected at the location of the SN in deep pre-explosion images is the progenitor star. From the main peak of the bolometric light curve and expansion velocities we constrain the mass of the ejecta to be ~2 Msun, the explosion energy to be E= 6-10 x 10^50 erg, and the 56Ni mass to be approximately 0.06 Msun. The progenitor star was composed of a helium core of 3 to 4 Msun and a thin hydrogen-rich envelope of ~0.1 M_sun with a main sequence mass estimated to be in the range of 12--15 Msun. Our models rule out progenitors with helium-core masses larger than 8 Msun, which correspond to M_ZAMS > 25 Msun. This suggests that a single star evolutionary scenario for SN 2011dh is unlikely.