Related papers: Are pulsars spun up or down by SASI spiral modes?
In certain mass ranges, massive stars can undergo a violent pulsation triggered by the electron/positron pair instability that ejects matter, but does not totally disrupt the star. After one or more of these pulsations, such stars are…
The effect of rotation on the explosion of core-collapse supernovae is investigated systematically in three-dimensional simulations. In order to obtain the critical conditions for explosion as a function of mass accretion rate, neutrino…
By 2D hydrodynamic simulations including a detailed equation of state and neutrino transport, we investigate the interplay between different non-radial hydrodynamic instabilities that play a role during the postbounce accretion phase of…
We discuss the spin evolution of pulsars in the case where a superfluid component of the star is coupled to the observable crust on long, spindown timescales. The momentum transfer from the superfluid interior results in an apparent decay…
Rotation of core-collapse supernovae (SNe) affects the neutrino emission characteristics. By comparing the neutrino properties of three three-dimensional SN simulations of a 15 M_sun progenitor (one non-rotating model and two models…
The success of the neutrino mechanism of core-collapse supernovae relies on the supporting action of two hydrodynamic instabilities: neutrino-driven convection and the Standing Accretion Shock Instability (SASI). Depending on the structure…
Two- and three-dimensional simulations demonstrate that hydrodynamic instabilities can lead to low-mode (l=1,2) asymmetries of the fluid flow in the neutrino-heated layer behind the supernova shock. This provides a natural explanation for…
Neutron stars such as pulsars and magnetars lose angular momentum primarily through electromagnetic dipole radiation, gravitational waves, $r$-mode oscillation, and also affected by fallback accretion processes. However, anomalous spin…
The core rotation rates of massive stars have a substantial impact on the nature of core-collapse supernovae and their compact remnants. We demonstrate that internal gravity waves (IGW), excited via envelope convection during a red…
A typical young pulsar slows down at an imperceptible rate, its spin period increasing by less than 10 microseconds over the course of a year. However, the inertia of a pulsar is so extreme that to effect this tiny change in rotation rate,…
Pulsars are rotating neutron stars that are observed to be slowing down, implying a loss of their rotational energy. There can be several different physical mechanisms involved in their spin-down process. The properties of fast-rotating…
Dynamical instabilities in protoneutron stars may produce gravitational waves whose observation could shed light on the physics of core-collapse supernovae. When born with sufficient differential rotation, these stars are susceptible to a…
We investigate the structure of the stalled supernova shock in both 2D and 3D and explore the differences in the effects of neutrino heating and the standing accretion shock instability (SASI). We find that early on the amplitude of the…
The loss of angular momentum due to unstable r-modes in hot young neutron stars has been proposed as a mechanism for achieving the spin rates inferred for young pulsars. One factor that could have a significant effect on the action of the…
We investigate whether angular momentum transport due to unstable pulsation modes can play a significant role in the rotational evolution of massive stars. We find that these modes can redistribute appreciable angular momentum, and moreover…
We study the effects of rotation on the dynamics, energetics and Ni-56 production of Pair Instability Supernova explosions by performing rotating two-dimensional ("2.5-D") hydrodynamics simulations. We calculate the evolution of eight low…
We extend our investigation of magnetic field evolution in three-dimensional flows driven by the stationary accretion shock instability (SASI) with a suite of higher-resolution idealized models of the post-bounce core-collapse supernova…
We present 2D simulations of pair-instability supernovae considering rapid rotation during their explosion phases. Recent studies of the Pop III star formation suggested that these stars could be born with a mass scale about 100 Msun and…
The explosion mechanism of core-collapse supernovae has not been fully understood yet but multi-dimensional fluid instabilities such as standing accretion shock instability (SASI) and convection are now believed to be crucial for shock…
During the core collapse of a massive star just before its supernova explosion, the amplification of asymmetric motions by the standing accretion shock instability (SASI) imprints on the neutrino flux and the gravitational waves a frequency…