Spontaneous Initiation of Detonations in White Dwarf Environments: Determination of Critical Sizes

摘要: Some explosion models for Type Ia supernovae (SNe Ia), such as the gravitationally confined detonation (GCD) or double sub-Chandrasekhar (DDSC) models, rely on spontaneous initiation of a in degenerate / material white dwarf (WD). The length scales pertinent to are notoriously unresolved multidimensional stellar simulations, prompting use results one-dimensional simulations at higher resolution, those performed this work, guidelines deciding whether not conditions reached dimensional full star successfully would lead onset detonation. Spontaneous relies existence suitable gradient self-ignition (induction) times fuel, which we set up with spatially localized nonuniformity temperature?a hot spot. We determine critical (smallest) sizes spots that still marginally result WD matter by integrating reactive Euler equations hydrodynamics code FLASH. quantify dependences composition, background temperature, peak geometry, and functional form temperature disturbance, many were hitherto largely unexplored literature. discuss implications our context modeling SNe Ia.