Models of pulsationally assisted gravitationally confined detonations with different ignition conditions

Abstract

Over the past decades, many explosion scenarios for Type Ia supernovae have been proposed and investigated including various combinations of deflagrations and detonations in white dwarfs of different masses up to the Chandrasekhar mass. One of these is the gravitationally confined detonation model. In this case a weak deflagration burns to the surface, wraps around the bound core, and collides at the antipode. A subsequent detonation is then initiated in the collision area. Since the parameter space for this scenario, that is, varying central densities and ignition geometries, has not been studied in detail, we used pure deflagration models of a previous parameter study dedicated to Type Iax supernovae as initial models to investigate the gravitationally confined detonation scenario. We aim to judge whether this channel can account for one of the many subgroups of Type Ia supernovae, or even normal events. To this end, we employed a comprehensive pipeline for three-dimensional Type Ia supernova modeling that consists of hydrodynamic explosion simulations, nuclear network calculations, and radiative transfer. The observables extracted from the radiative transfer are then compared to observed light curves and spectra. The study produces a wide range in masses of synthesized 56Ni ranging from 0.257 to 1.057 M⊙, and, thus, can potentially account for subluminous as well as overluminous Type Ia supernovae in terms of brightness. However, a rough agreement with observed light curves and spectra can only be found for 91T-like objects. Although several discrepancies remain, we conclude that the gravitationally confined detonation model cannot be ruled out as a mechanism to produce 91T-like objects. However, the models do not provide a good explanation for either normal Type Ia supernovae or Type Iax supernovae.

Dimming the Lights: 2D Simulations of Deflagrations of Hybrid C/O/Ne White Dwarfs Using FLASH

“…The key difference between the two is where the detonation ignites; a PGCD will ignite the detonation inside the remnant's dense core, where the burning ashes mix with the fuel, while a PRD ignites an inward-moving detonation at the interface of the remnant's core and the fallback ashes. Lach et al (2022b) also tested their models in the gravitationally confined detonation scenario, where a deflagration wraps around the star and collides, sparking a detonation. This mechanism produced a much higher ejected 56 Ni content (0.257-1.057 M ☉ ), with light curves and spectra most similar to 91T-like events, rather than Type Ia or Iax.…”

Type Ia Supernova Explosions in Binary Systems: A Review

“…The explosion mechanism depends mainly on the question of whether the WD explodes near the Chandrasekhar mass (e.g., Nomoto et al 1984;Livio & Riess 2003;Röpke & Niemeyer 2007;Röpke et al 2007b;Mazzali et al 2007;Kasen et al 2009;Ilkov & Soker 2012;Rabinak et al 2012;Jordan et al 2012b;Seitenzahl et al 2013b;Fink et al 2014;Lach et al 2022Lach et al , 2022c or at a mass below this limit (the "sub-Chandrasekhar-mass" explosion scenario, e.g., Woosley et al 1986;Benz et al 1989;Fink et al 2007;Rosswog et al 2009a;Raskin et al 2009;Sim et al 2010;Pakmor et al 2010;Kushnir et al 2013;Townsley et al 2019;Gronow et al 2020Gronow et al , 2021a. To provide clues on the yet poorly understood origin and explosion mechanism of SNe Ia, one needs to compare the observational features predicted by different explosion mechanisms in the context of the progenitor models discussed in Section 3.1 with the observations.…”

“…A number of explosion models have been proposed to cover various progenitor scenarios of SNe Ia (Hillebrandt et al 2013, for a recent review), including near-Chandrasekhar-mass deflagrations (Nomoto et al 1984;Jordan et al 2012a;Kromer et al 2013a;Fink et al 2014;Lach et al 2022), near-Chandrasekhar-mass delayed detonations (Arnett 1969;Khokhlov 1991;Gamezo et al 2005;Röpke & Niemeyer 2007;Rabinak et al 2012;Seitenzahl et al 2013b), gravitationally confined detonations (Jordan et al 2008;Seitenzahl et al 2016;Lach et al 2022c), sub-Chandrasekhar-mass double detonations (Nomoto 1982b(Nomoto , 1982aWoosley et al 1986;Iben et al 1987;Livne 1990;Woosley & Weaver 1994;Fink et al 2007;Moll & Woosley 2013;Gronow et al 2020Gronow et al , 2021aBoos et al 2021) and violent mergers (Pakmor et al 2010(Pakmor et al , 2011. A schematic overview of various SN Ia explosion models proposed in the framework of either Chandrasekhar-mass or sub-Chandrasekhar-mass explosion is presented in Figure 3.…”

Pre-explosion helium shell flash in type Ia supernovae

“…The community is far from a consensus on the leading SN Ia scenario(s). Therefore, studies continue to explore each one of these stellar binary scenarios (e.g., some examples from the last two years, Cui et al 2020;Zou, Zhou, & Huang 2020;Blondin et al 2021;Clark et al 2021;Ablimit 2021;Chandra et al 2021;Liu et al 2021;Meng & Luo 2021;Michaely 2021;Wang et al 2021;Zeng et al 2021;Acharova, Sharina, & Kazakov 2022;Chu et al 2022;Cui & Li 2022;Dimitriadis et al 2022;Ferrand et al 2022;Lach et al 2022;Liu, Roepke, & Zeng 2022;Livneh & Katz 2022;Mazzali et al 2022;Pakmor et al 2022;Patra et al 2022;Piersanti et al 2022;Sharon & Kushnir 2022;Shingles et al 2022).…”