A Diversity of Wave-driven Presupernova Outbursts

Abstract

Many core-collapse supernova (SN) progenitors show indications of enhanced pre-SN mass loss and outbursts, some of which could be powered by wave energy transport within the progenitor star. Depending on the star's structure, convectively excited waves driven by late-stage nuclear burning can carry substantial energy from the core to the envelope, where the wave energy is dissipated as heat. We examine the process of wave energy transport in single-star SNe progenitors with masses between 11 and 50 M_⊙. Using MESA stellar evolution simulations, we evolve stars until core collapse and calculate the wave power produced and transmitted to the stars' envelopes. These models improve upon prior efforts by incorporating a more realistic wave spectrum and nonlinear damping effects, reducing our wave-heating estimates by ~1 order of magnitude compared to prior work. We find that waves excited during oxygen/neon burning typically transmit ~10⁴⁶–10⁴⁷ erg of energy at 0.1–10 yr before core collapse in typical (M < 30 M_⊙) SN progenitors. High-mass progenitors can often transmit ~10⁴⁷–10⁴⁸ erg of energy during oxygen/neon burning, but this tends to occur later, at about 0.01–0.1 yr before core collapse. Pre-SN outbursts may be most pronounced in low-mass SN progenitors (M ≾ 12 M_⊙) undergoing semidegenerate neon ignition and in high-mass progenitors (M ≳ 30 M_⊙) exhibiting convective shell mergers.