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

Abstract

Stripped-envelope supernovae (Type IIb, Ib, Ic) showing little or no hydrogen are one of the main classes of explosions of massive stars. Their origin and the evolution of their progenitors are not fully understood as yet. Very massive single stars stripped by their own winds ( 25 − 30M at solar metallicity) are considered viable progenitors of these events. However, recent 1D core-collapse simulations show that some massive stars may collapse directly onto black holes after a failed explosion, with weak or no visible transient. In this letter, we estimate the effect of direct collapse onto 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 corecollapse 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 with a thin hydrogen envelope left (IIb progenitor candidates) do, unless we invoke increased wind mass-loss rates. This result increases the existing tension between the single-star scenario for stripped-envelope supernovae and their observed rates and properties. At face value, our results point towards an even higher contribution of binary progenitors for 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.

Explodability fluctuations of massive stellar cores enable asymmetric compact object mergers such as GW190814

“…Indeed, several recent studies suggest that the initial-toremnant mass relations traditionally employed in BPS simulations might not be representative of the true explosion landscape (O'Connor & Ott 2011;Ugliano et al 2012;Sukhbold & Woosley 2014;Pejcha & Thompson 2015;Ertl et al 2016;Müller et al 2016;Ebinger et al 2019;Woosley 2019;Ertl et al 2020;Schneider et al 2021;Patton & Sukhbold 2020;Mandel et al 2021;Zapartas et al 2021;Patton et al 2021;Laplace et al 2021;Aguilera-Dena et al 2021). Whether a star forms a NS or a BH within the neutrino-driven explosion paradigm, is largely determined by the pre-SN density (or equivalently, the "compactness"; O'Connor & Ott 2011) of the stellar core.…”

Binary Black Hole Formation with Detailed Modeling: Stable Mass Transfer Leads to Lower Merger Rates

“…In an effort to include up-to-date methods of binary evolution into studies of large binary populations, groups have implemented hybrid methods in their studies. These methods typically use population synthesis codes combined with detailed simulations of stellar and binary evolution (Nelson 2012;Chen et al 2014;Shao et al 2019;Bavera et al 2021;Román-Garza et al 2021;Zapartas et al 2021;Shao & Li 2021). These studies show that including more detailed modeling of binary interactions may reveal details that are missed using simpler prescriptions.…”

The spins of compact objects born from helium stars in binary systems

“…Figure 5 also shows a few magnetar rotation period estimates obtained by modeling "normal" type Ib SNe, which likely arise from He stars formed in binaries (e.g., Zapartas et al 2021). Afsariardchi et al (2020) provided estimates for many events by assuming a typical ejecta mass of either 2 M or 5 M .…”

“…The discrepancy is even worse when one considers that the ejecta mass of our massive models would be far larger than 5 M , meaning that the ejecta velocity would be smaller than 15, 000 km/s and those SNe would not appear broad-lined. Another problem with this scenario is that such massive He stars may be less likely to form via a common envelope event (Klencki et al 2020;Marchant et al 2021;van Son et al 2021), and less likely to explode (O'Connor & Ott 2011;Zapartas et al 2021). This may disfavor magnetars as the power source of most Ic-BL SNe.…”