Abstract
This letter complements a formation scenario of the progenitor of the supernova iPTF13bvn proposed by Hirai. Although the scenario was successful in reproducing various observational ...features of the explosion and pre-explosion photometry by assuming that the progenitor had a relatively large black hole (BH) companion, it lacked an explanation for the origin of the BH itself. We now explore the possible evolutionary paths towards this binary with a relatively large BH companion. We found that the BH was probably produced by a very massive star that experienced common envelope evolution. According to our mesa stellar models, the primary mass should have been
${\gtrsim }70\, {\rm M}_{\odot }$
to reproduce the required remnant mass and final separation. This indicates that iPTF13bvn was likely a rare case and normal Type Ib supernovae originate from different paths.
Abstract We explore the evolution of massive stars (>8 M ⊙ ) with 1D models and present analytical fits to the masses and binding energies of the convective portions of their envelopes. These fits ...are given as functions of total mass, metallicity, and surface temperature (used as a proxy for evolutionary phase). They enable the application of the two-stage common envelope (CE) formalism in rapid binary population synthesis frameworks. We estimate that the degree of orbital hardening following CE ejection spans 6 orders of magnitude and is a very strong function of the accretor mass, and, to a lesser extent, donor evolutionary phase.
We carry out a comprehensive study of supernova ejecta-companion interaction in massive binary systems. Our aim is to physically understand the kinematics of the interaction and predict observational ...signatures. To do this, we perform simulations over a vast parameter space of binary configurations, varying the masses of the progenitor and companion, structure of the companion, explosion energy, and orbital separation. Our results were not so consistent with the classical models developed by Wheeler et al. (1975), sometimes deviating by an order of magnitude. Therefore, we construct an alternative simple model that explains the simulated results reasonably well and that can be used to estimate impact velocities for arbitrary explosion profiles and companion star structures. We then investigate the long term evolution after the supernova, where the companion can be inflated by the energy injected into the star. We find that the companion can become more than an order of magnitude overluminous immediately after the supernova but quickly fades away after ∼10 years and returns to its original luminosity in about a thermal timescale of the star. Finally, we also discuss the possible surface contamination of heavy elements from the slower ejecta.
Abstract
We use the rapid binary population synthesis code COMPAS to investigate commonly used prescriptions for the determination of mass transfer stability in close binaries and the orbital ...separations after stable mass transfer. The degree of orbital tightening during nonconservative mass transfer episodes is governed by the poorly constrained angular momentum carried away by the ejected material. Increased orbital tightening drives systems toward unstable mass transfer leading to a common envelope. We find that the fraction of interacting binaries that will undergo only stable mass transfer throughout their lives fluctuates between a few and ∼20% due to uncertainty in the angular momentum loss alone. If mass transfer is significantly nonconservative, stability prescriptions that rely on the assumption of conservative mass transfer underpredict the number of systems which experience unstable mass transfer and stellar mergers. This may substantially impact predictions about the rates of various transients, including luminous red novae, stripped-envelope supernovae, X-ray binaries, and the progenitors of coalescing compact binaries.
ABSTRACT
We perform 3D hydrodynamical simulations of a common-envelope event involving a 12$\, \rm {M}_{\odot }$ red supergiant donor. Massive stars are expected to be qualitatively different from ...low-mass stars as their envelopes have significant support from radiation pressure, which increases both the final separation and amount of mass ejected through the common-envelope interaction. We perform adiabatic simulations that include radiation energy through the equation of state, which results in ejecting 60 per cent more mass (up to two thirds of the total envelope mass becoming unbound, or more) and yield a 10 per cent larger final separation compared to simulations that assume an ideal gas. When also including recombination energy, we find that at least three quarters of the envelope, and possibly the entire envelope, may be unbound. The final separation further increases by almost 20 per cent. The additional amount of ejected material is mainly due to energy injected from helium recombination. Hydrogen recombination plays a comparatively small role, as it mainly occurs in gas that has already become unbound. We conclude that the internal energy of the envelope can be a significant energy source for ejecting the common envelope, but ultimately radiation transport and convection need to be included.
ABSTRACT
We explore a new scenario for producing stripped-envelope supernova progenitors. In our scenario, the stripped-envelope supernova is the second supernova of the binary, in which the envelope ...of the secondary was removed during its red supergiant phase by the impact of the first supernova. Through 2D hydrodynamical simulations, we find that ∼50–90 ${{\ \rm per\ cent}}$ of the envelope can be unbound as long as the pre-supernova orbital separation is ≲5 times the stellar radius. Recombination energy plays a significant role in the unbinding, especially for relatively high mass systems (≳18 M⊙). We predict that more than half of the unbound mass should be distributed as a one-sided shell at about ∼10–100 pc away from the second supernova site. We discuss possible applications to known supernova remnants such as Cassiopeia A, RX J1713.7−3946, G11.2−0.3, and find promising agreements. The predicted rate is ∼0.35–1${{\ \rm per\ cent}}$ of the core-collapse population. This new scenario could be a major channel for the subclass of stripped-envelope or type IIL supernovae that lack companion detections like Cassiopeia A.
ABSTRACT
Type Ibn supernovae (SNe Ibn) are intriguing stellar explosions whose spectra exhibit narrow helium lines with little hydrogen. They trace the presence of circumstellar material (CSM) formed ...via pre-SN eruptions of their stripped-envelope progenitors. Early work has generally assumed that SNe Ibn come from massive Wolf–Rayet (WR) stars via single-star evolution. In this paper, we report ultraviolet (UV) and optical observations of two nearby Type Ibn SNe 2006jc and 2015G conducted with the Hubble Space Telescope (HST) at late times. A point source is detected at the position of SN 2006jc, and we confirm the conclusion of Maund et al. that it is the progenitor’s binary companion. Its position on the Hertzsprung–Russell (HR) diagram corresponds to a star that has evolved off the main sequence (MS); further analysis implies a low initial mass for the companion star (M2 ≤ 12.3$^{+2.3}_{-1.5}$ M⊙) and a secondary-to-primary initial mass ratio very close to unity (q = M2/M1 ∼ 1); the SN progenitor’s hydrogen envelope had been stripped through binary interaction. We do not detect the binary companion of SN 2015G. For both SNe, the surrounding stellar populations have relatively old ages and argue against any massive WR stars as their progenitors. These results suggest that SNe Ibn may have lower mass origins in interacting binaries. As a result, they also provide evidence that the giant eruptions commonly seen in massive luminous blue variables (LBVs) can also occur in much lower mass, stripped-envelope stars just before core collapse.
ABSTRACT
We examine the sensitivity of neutrino emission to stellar evolution models for a 15 M⊙ progenitor, paying particular attention to a phase prior to the collapse. We demonstrate that the ...number luminosities in both electron-type neutrinos (νe) and their antipartners ($\bar{\nu }_\mathrm{ e}$) differ by more than an order of magnitude by changing spatial resolutions and nuclear network sizes on stellar evolution models. We also develop a phenomenological model to capture the essential trend of the diversity, in which neutrino luminosities are expressed as a function of central density, temperature, and electron fraction. In the analysis, we show that the neutrino luminosity can be well characterized by these central quantities. This analysis also reveals that the most influential quantity to the time evolution of νe luminosity is matter density, while it is temperature for $\bar{\nu }_\mathrm{ e}$. These qualitative trends will be useful and applicable to constrain the physical states of progenitors at the final stages of stellar evolution from future neutrino observations, although more detailed systematic studies including various mass progenitors are required to assess the applicability.
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