Pulsational Pair-instability Supernovae

Multidimensional simulations of pair-instability supernovae

We present preliminary results from multidimensional numerical studies of pair instability supernova (PSN), studying the fluid instabilities that occur in multiple spatial dimensions. We use the new radiation-hydrodynamics code, CASTRO, and introduce a new mapping procedure that defines the initial conditions for the multidimensional runs in such a way that conservation of physical quantities i...

Can very massive stars avoid Pair-instability Supernovae ?

Very massive primordial stars (140 M < M < 260 M ) are supposed to end their lives as pair-instability supernovae. Such an event can be traced by a typical chemical signature in low metallicity stars, but at the present time, this signature is lacking in the extremely metal-poor stars we are able to observe. Does it mean that those very massive objects did not form, contrarily to the primordial...

Pair-Instability Supernovae, Gravity Waves, and Gamma-Ray Transients

Growing theoretical evidence suggests that the first generation of stars may have been quite massive (∼ 100 − 300 M ). If they retain their high mass until death, such stars will, after about 3Myr, make pair-instability supernovae. Theoretical models for these explosions have been studied in the literature for about four decades, but very few of these studies have included the effects of rotati...

A Criterion for Nuclear-Energized Pulsational Instability

Multimodal Radial Pulsational Instability In A Prenova Model

A prenova model, consisting of a white dwarf unstably burning a shell of accreted hydrogen, was tested for stability against radial pulsations. The pulsational analysis included terms due to thermal imbalance. The model was found to be pulsationally unstable in all of the modes examined, save one in which the thermal-imbalance integrals made the crucial damping contribution. An evaluation of so...