![]() The labels are as follows: Nabi & Klapdor-Kleingrothaus (2004, NKK), Langanke & Martínez-Pinedo (2001, LMP), Oda et al. The inverse ( β-decay) rates were taken from consistent sources. Sources of electron-capture rates considered for the calculation of d Y e/ d t in the NSE ashes of the O deflagration. At such temperatures the material is no longer completely degenerate and can expand in response to the nuclear binding energy that has been released at the burning front. Instead, the increase in temperature just accelerates the rate of fusion until the temperature becomes so high (approximately 10 10 K) that the composition can be said to be in nuclear statistical equilibrium (NSE e.g. Consequently, and owing to the high degree of degeneracy of the material, a thermonuclear runaway ensues since there is little to no expansion resulting from the temperature increase. The collapse of the ONe core is triggered by electron captures on 24Mg and, more importantly, 20Ne, which releases enough energy through the γ-decay of 20O to ignite O-burning via 16O + 16O fusion ( Miyaji et al. 2015), making it also possible for ECSNe to produce SNe of type Ib/c, depending upon the degree of stripping by the companion star ( Tauris et al. It is likely that the progenitor stars of ECSNe have a binary companion ( Sana et al. In the former case, if the SN is from a single star, a type IIP or IIn-P supernova would be produced with a luminosity lower than ( Smith 2013) or similar to ( Tominaga et al. The simulations with the highest ignition density ( log 10 ρ c = 10.3), representing the case where semiconvective mixing is very efficient, show clear signs that the core will collapse into a neutron star.Įlectron-capture supernovae (ECSNe) and the accretion-induced collapse of oxygen-neon (ONe) white dwarfs (WDs) are phenomena in which a degenerate ONe core is postulated to collapse into a neutron star ( Miyaji et al. The masses of the bound remnants double when Coulomb corrections are included in the equation of state, however they still do not exceed the effective Chandrasekhar mass and, hence, would not collapse into neutron stars. These simulations represent the case in which semiconvective mixing during the electron-capture phase preceding the deflagration is inefficient. ![]() Instead, almost a solar mass of material becomes unbound from the cores, leaving bound remnants. In the simulations with intermediate and low ignition density, the cores do not appear to collapse into neutron stars. The 3D hydrodynamic simulations presented in this work begin from a centrally confined flame structure using a level-set-based flame approach and are performed in 256 3 and 512 3 numerical resolutions. The intermediate density case is perhaps the most realistic, being based on recent nuclear physics calculations and 1D stellar models. The oxygen deflagration is simulated in oxygen-neon cores with three different central ignition densities. The main aim is to determine whether these events are thermonuclear or core-collapse supernova explosions, and hence whether neutron stars are formed by such phenomena. By simulating the oxygen deflagration with multidimensional hydrodynamics and a level-set-based flame approach, new insights can be gained into the explosive deaths of 8−10 M ⊙ stars and oxygen-neon white dwarfs that accrete material from a binary companion star. In this work, the oxygen deflagration phase is simulated for the first time using multidimensional hydrodynamics.Īims. These types of core collapse events are postulated to explain several astronomical phenomena. In the classical picture, electron-capture supernovae and the accretion-induced collapse of oxygen-neon white dwarfs undergo an oxygen deflagration phase before gravitational collapse produces a neutron star. 2, 69120 Heidelberg, Germanyģ Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, AustraliaĤ ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), The University of Sydney, NSW 2006, AustraliaĬontext. Edelmann 1ġ Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, GermanyĮ-mail: Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle-Str. ![]() Astronomical objects: linking to databases.Including author names using non-Roman alphabets.Suggested resources for more tips on language editing in the sciences Punctuation and style concerns regarding equations, figures, tables, and footnotes ![]()
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