Cococubed.com Ignition of White Dwarf Supernova
Home Astronomy research   Software Infrastructure:      MESA      FLASH-X      STARLIB      MESA-Web      starkiller-astro      My instruments   White dwarf pulsations:      12C(α,γ) & overshooting      Probe of 12C(α,γ)16O      Impact of 22Ne      Impact of ν cooling      Variable white dwarfs      MC reaction rates      Micronovae      Novae   White dwarf supernova:      Stable nickel production      Remnant metallicities      Colliding white dwarfs      Merging white dwarfs      Ignition conditions      Metallicity effects      Central density effects      Detonation density      Tracer particle burning      Subsonic burning fronts      Supersonic fronts      W7 profiles   Massive stars:      Pop III with HST/JWST      Rotating progenitors      3D evolution to collapse      MC reaction rates      Pre-SN variations   Massive star supernova:      Yields of radionuclides      26Al & 60Fe      44Ti, 60Co & 56Ni      SN 1987A light curve      Constraints on Ni/Fe      An r-process      Effects of 12C +12C   Neutron Stars and Black Holes:      Black Hole spectrum      Mass Gap with LVK      Compact object IMF      He burn neutron stars   Neutrino Emission:      Neutrino emission from stars      Identifying the Pre-SN      Neutrino HR diagram      Pre-SN Beta Processes      Pre-SN neutrinos   Stars:      Hypatia catalog      SAGB stars      Nugrid Yields I      He shell convection      BBFH at 40 years      γ-rays within 100 Mpc      Iron Pseudocarbynes   Pre-Solar Grains:      C-rich presolar grains      SiC Type U/C grains      Grains from massive stars      Placing the Sun      SiC Presolar grains   Chemical Evolution:      Radionuclides in 2020s      Zone models H to Zn      Mixing ejecta   Thermodynamics & Networks      Skye EOS      Helm EOS      Five EOSs      Equations of State      12C(α,γ)16O Rate      Proton-rich NSE      Reaction networks      Bayesian reaction rates   Verification Problems:      Validating an astro code      Su-Olson      Cog8      Mader      RMTV      Sedov      Noh Software Instruments AAS Journals    2024 AAS YouTube    2024 AAS Peer Review Workshops 2024 ASU Energy in Everyday Life 2024 MESA Classroom Outreach and Education Materials Other Stuff:    Bicycle Adventures    Illustrations    Presentations Contact: F.X.Timmes my one page vitae, full vitae, research statement, and teaching statement.	Local Ignition in Carbon-Oxygen White Dwarfs. I. One-Zone Ignition and Spherical Shock Ignition of Detonations (2006) The details of ignition of Type Ia supernovae remain fuzzy, despite the importance of this input for any large-scale model of the final explosion. In this article, we begin a process of understanding the ignition of these hot spots by examining the burning of one zone of material, and then we investigate the ignition of a detonation due to rapid heating at single point. We numerically measure the ignition delay time for onset of burning in mixtures of degenerate material and provide fitting formulae for conditions of relevance in the Type Ia problem. Using the neon abundance as a proxy for the white dwarf progenitor's metallicity, we then find that ignition times can decrease by d$\simeq$ ~20% with the addition of even 5% of neon by mass. When temperature fluctuations that successfully kindle a region are very rare, such a reduction in ignition time can increase the probability of ignition by orders of magnitude. If the neon comes largely at the expense of carbon, a similar decrease in the ignition time can occur. We then consider the ignition of a detonation by an explosive energy input in one localized zone, for example, a Sedov blast wave leading to a shock-ignited detonation. Building on previous work on curved detonations, we confirm that surprisingly large inputs of energy are required to successfully launch a detonation, leading to required match heads of $\approx$ 4500 detonation thicknesses -- tens of centimeters to hundreds of meters -- which is orders of magnitude larger than naive considerations might suggest. This is a very difficult constraint to meet for some pictures of a deflagration-to-detonation transition, such as a Zel'dovich gradient mechanism ignition in the distributed burning regime.