Sample interview questions: Can you explain the concept of cosmic rays and their acceleration mechanisms?
Sample answer:
Concept of Cosmic Rays:
Cosmic rays are highly energetic particles that originate from outside the Earth’s atmosphere, primarily from supernova explosions and active galactic nuclei. These particles include protons, nuclei of heavier elements, electrons, and positrons, with energies ranging from a few billion electron volts (GeV) to over 10^20 GeV.
Acceleration Mechanisms:
Cosmic rays are accelerated through various mechanisms in astrophysical environments:
- Supernova Remnants (SNRs): Shock waves formed by supernova explosions accelerate particles through diffusive shock acceleration (DSA). Protons interact with the shock front, gaining energy through repeated collisions.
- Active Galactic Nuclei (AGNs): The supermassive black holes at the centers of galaxies emit jets of high-energy particles. Particles can be accelerated by Fermi acceleration in the strong magnetic fields within these jets.
- Pulsar Wind Nebulae (PWNe): Pulsars release energetic particle… Read full answer