Related papers: Numerical Simulations of Cosmic-Ray Acceleration a…
We study the effect of cosmic ray (CR) acceleration in the massive compact star cluster Westerlund 1 in light of its recent detection in $\gamma$-rays. Recent observations reveal a $1/r$ radial distribution of the CR energy density. Here we…
The continuing difficulty of achieving a reliable explosion in simulations of core-collapse supernovae, especially for more massive stars, has led to speculation concerning the observable transients that might be produced if such a…
Core-Collapse supernovae arise from stars greater than 8 $\msun$. These stars lose a considerable amount of mass during their lifetime, which accumulates around the star forming wind-blown bubbles. Upon the death of the star in a…
The mechanism of core-collapse supernova explosions must draw on the energy provided by gravitational collapse and transfer the necessary fraction to the kinetic and internal energy of the ejecta. Despite many decades of concerted…
In order to better connect core-collapse supernovae (CCSN) theory with its observational signatures, we have developed a simulation pipeline from the onset of core collapse to beyond shock breakout. Using this framework, we present a…
We perform kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). Bohm-like diffusion assumed, and simple models for Alfvenic drift and dissipation…
We present four ab initio axisymmetric core-collapse supernova simulations for 12, 15, 20, and 25 $M_\odot$ progenitors. All of the simulations yield explosions and have been evolved for at least 1.2 seconds after core bounce and 1 second…
Non-relativistic shocks accelerate ions to highly relativistic energies provided that the orientation of the magnetic field is closely aligned with the shock normal (quasi-parallel shock configuration). In contrast, quasi-perpendicular…
For more than fifty years, it has been believed that cosmic ray (CR) nuclei are accelerated to high energies in the rapidly expanding shockwaves created by powerful supernova explosions. Yet observational proof of this conjecture is still…
The recent observations revealed that the cosmic-ray (CR) proton spectrum showed a complex structure: the hardening at $\rm \sim 200~GeV$ and softening at $\rm \sim 10~TeV$. However, so far the physical origins of this spectral feature…
Observations and theory suggest that core-collapse supernovae can span a range of explosion energies, and when sub-energetic, the shockwave initiating the explosion can decelerate to speeds comparable to the escape speed of the progenitor.…
The origin of cosmic rays (CRs) has puzzled scientists since the pioneering discovery by Victor Hess in 1912. In the last decade, however, modern supercomputers have opened a new window on the processes regulating astrophysical…
How do massive stars explode? Progress toward the answer is driven by increases in compute power. Petascale supercomputers are enabling detailed three-dimensional simulations of core-collapse supernovae. These are elucidating the role of…
We investigate escape of cosmic ray (CR) electrons from a supernova remnant (SNR) to interstellar space. We show that CR electrons escape in order from high energies to low energies like CR nuclei, while the escape starts later than the…
Supernovae (SNe) with strong interactions with circumstellar material (CSM) are promising candidate sources of high-energy neutrinos and gamma rays, and have been suggested as an important contributor to Galactic cosmic rays beyond 1 PeV.…
New two-dimensional, high-resolution calculations of a core collapse supernova in a 15 Msol blue supergiant are presented, which cover the entire evolution from shock revival until the first few hours of the explosion. Explosive…
We explore a possible scenario of the explosion as a result of core collapses of rotating massive stars that leave a black hole by performing a radiation-viscous-hydrodynamics simulation in numerical relativity. We take moderately and…
We present the first three dimensional (3D) simulation of the final minutes of iron core growth in a massive star, up to and including the point of core gravitational instability and collapse. We self-consistently capture the development of…
We perform two- (2D) and three-dimensional (3D) hydrodynamics simulations of convective oxygen shell-burning that takes place deep inside a massive progenitor star of a core-collapse supernova. Using one dimensional (1D) stellar evolution…
We present high-resolution hydrodynamical simulations aimed at following the gravitational collapse of a gas core, in which a turbulent spectrum of velocity is implemented only initially. We determine the maximal value of the ratio of…