Letter to the Editor

Revisiting the explodability of single massive star progenitors of stripped-envelope supernovae

¹ Département d’Astronomie, Université de Genève, Chemin Pegasi 51, 1290 Versoix, Switzerland
e-mail: ezapartas@gmail.com
² Department of Physics, Columbia University, New York, NY 10027, USA
³ Center for Computational Astrophysics, Flatiron Institute, 162 5th Ave, New York, NY 10010, USA
⁴ Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 1800 Sherman Avenue, Evanston, IL 60201, USA
⁵ Department of Physics, Anhui Normal University, Wuhu city, Anhui Province 241000, PR China
⁶ DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark

Received: 9 June 2021
Accepted: 23 September 2021

Abstract

Stripped-envelope supernovae (Types IIb, Ib, and Ic) that show little or no hydrogen comprise roughly one-third of the observed explosions of massive stars. Their origin and the evolution of their progenitors are not yet fully understood. Very massive single stars stripped by their own winds (≳25−30 M_⊙ at solar metallicity) are considered viable progenitors of these events. However, recent 1D core-collapse simulations show that some massive stars may collapse directly into black holes after a failed explosion, with a weak or no visible transient. In this Letter, we estimate the effect of direct collapse into a black hole on the rates of stripped-envelope supernovae that arise from single stars. For this, we compute single-star MESA models at solar metallicity and map their final state to their core-collapse outcome following prescriptions commonly used in population synthesis. According to our models, no single stars that have lost their entire hydrogen-rich envelope are able to explode, and only a fraction of progenitors left with a thin hydrogen envelope do (IIb progenitor candidates), unless we use a prescription that takes the effect of turbulence into account or invoke increased wind mass-loss rates. This result increases the existing tension between the single-star paradigm to explain most stripped-envelope supernovae and their observed rates and properties. At face value, our results point toward an even higher contribution of binary progenitors to stripped-envelope supernovae. Alternatively, they may suggest inconsistencies in the common practice of mapping different stellar models to core-collapse outcomes and/or higher overall mass loss in massive stars.