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Variable Hα Emission in the Nebular Spectra of the Low-luminosity Type Ia SN2018cqj/ATLAS18qtd. ACTA ACUST UNITED AC 2020. [DOI: 10.3847/1538-4357/ab6323] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Poludnenko AY, Chambers J, Ahmed K, Gamezo VN, Taylor BD. A unified mechanism for unconfined deflagration-to-detonation transition in terrestrial chemical systems and type Ia supernovae. Science 2019; 366:366/6465/eaau7365. [DOI: 10.1126/science.aau7365] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/20/2019] [Indexed: 11/02/2022]
Abstract
The nature of type Ia supernovae (SNIa)—thermonuclear explosions of white dwarf stars—is an open question in astrophysics. Virtually all existing theoretical models of normal, bright SNIa require the explosion to produce a detonation in order to consume all of stellar material, but the mechanism for the deflagration-to-detonation transition (DDT) remains unclear. We present a unified theory of turbulence-induced DDT that describes the mechanism and conditions for initiating detonation both in unconfined chemical and thermonuclear explosions. The model is validated by using experiments with chemical flames and numerical simulations of thermonuclear flames. We use the developed theory to determine criteria for detonation initiation in the single-degenerate Chandrasekhar-mass SNIa model and show that DDT is almost inevitable at densities of 107 to 108 grams per cubic centimeter.
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Affiliation(s)
- Alexei Y. Poludnenko
- Department of Aerospace Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Jessica Chambers
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA
| | - Kareem Ahmed
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA
| | - Vadim N. Gamezo
- Laboratories for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375, USA
| | - Brian D. Taylor
- Munitions Directorate, Air Force Research Laboratory, Eglin, FL 32542, USA
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