Overview

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Lectures

Coursework

Overview

Outline

The LHC accelerates protons to kinetic energies of up to 7000 times their rest mass—a huge technological achievement. Yet, every second, over 500 million particles with energies greater than this collide with the Earth. Where do these particles come from, and how are they accelerated to these astonishing energies? These are, in fact, still open questions in astrophysics. In this module, we will look at the observational evidence for particle acceleration in astrophysical objects, the mechanisms available to accelerate particles, and some of the likely sources, including supernovae and supernova remnants, neutron stars, and active galaxies.

Aims

1. present the evidence for high-energy processes in astrophysics, in both the electromagnetic spectrum (from gamma rays to radio) and in high-energy particles (cosmic rays and neutrinos);
2. describe the techniques and instruments used to detect high-energy particles from astrophysical sources (gamma rays, neutrinos and cosmic rays);
3. discuss the mechanisms by which particles can be accelerated to high energies in astrophysical environments;
4. identify and describe those classes of astrophysical objects that provide such an environment, in particular supernovae and gamma ray bursts, pulsars and supernova remnants, and active galactic nuclei;
5. discuss remaining open questions and future prospects in the field of particle astrophysics.

Learning outcomes

1. describe the mechanisms by which electromagnetic radiation is produced in the presence of a population of fast particles, namely synchrotron radiation, bremsstrahlung, the inverse Compton effect and neutral pion decays;
2. explain how cosmic rays, TeV gamma rays and neutrinos are detected by current and planned experiments;
3. summarise the observational evidence, from electromagnetic radiation and other observational signals, for the presence of populations of high-energy particles in some astrophysical objects;
4. derive expressions relating to diffusive shock acceleration in astrophysical environments;
5. explain the constraints that the observations place on the nature of astrophysical sources;
6. give a list of candidate source types, and describe the physical conditions therein and the observational evidence for populations of fast particles in these objects;
7. explain how observations can be used to distinguish different production mechanisms and discuss the importance of coordinated observing campaigns at different wavelengths;
8. summarise the current state of knowledge in the field and discuss possible future developments.

Assessment

The assessment for this course will consist of:

an end-of-semester exam (85%)

Rubric: answer question ONE (compulsory: 30 marks) and TWO other questions (20 marks each).
A practice exam paper will be provided.

five short class tests (5×3%)

These will be in lecture slots and will test your knowledge and understanding of the taught material.