Acceleration in astrophysics

Particle Acceleration in Cosmic Sites Astrophysics Issues in our Understanding of Cosmic Rays

Particles are accelerated in cosmic sites probably under conditions very different from those at terrestrial particle accelerator laboratories. Nevertheless, specific experiments which explore plasma conditions and stimulated particle acceleration carry significant potential to illuminate some aspects of the cosmic particle acceleration process. Here we summarize what we have learned about cosm...

Laboratory Laser Acceleration and High Energy Astrophysics: γ–ray Bursts and Cosmic Rays

Recent experimental progress in laser acceleration of charged particles (electrons) and its associated processes has shown that intense electromagnetic pulses can promptly accelerate charged particles to high energies and that their energy spectrum is quite hard. On the other hand some of the high energy astrophysical phenomena such as extremely high energy cosmic rays and energetic components ...

Astrophysics.

Using the oscillation frequencies of α Cen A recently discovered by Bouchy & Carrier (2001, 2002), the available astrometric, photometric and spectroscopic data, we tried to improve the calibration of the visual binary system α Cen. With the revisited masses of Pour-baix et al. (2002) we do not succeed to obtain a solution satisfying all the seismic observational constraints. Relaxing the const...

Generating Process Explanations in Nuclear Astrophysics Generating Explanations in Astrophysics

In this paper we describe ASTRA, a computational aid for generating process explanations in nuclear astrophysics. The system operates in two stages, the rst using knowledge of quantum theory to produce a set of legal reactions among elements and the second searching for pathways of such reactions that explain the evolution of some element in terms of lighter ones. ASTRA has found apparently nov...

Astrophysics.