MPhys Physics

Foundations in radiative transfer

Flux, intensity, radiative transfer equation, optical depth, mean free path, equivalent width of emission lines, emission/absorption line profiles.

The interstellar medium

Composition of the ISM, properties of gas within galaxies, photo-ionization regions, heating/cooling mechanisms, dust grain properties, absorption and emission by dust.

Radiative processes in astrophysics

a.    Bound-bound transitions: Spectral line formation, emission lines as diagnostics of ISM conditions, Einstein coefficients, collisional excitation

b.    Bound-free: continuum processes in the ISM, nebular continuum, formation of spectral breaks

c.    Free-free: thermal Bremsstrahlung

d.    Relativistic emission: synchrotron radiation and Compton scattering

Physics of shocks

Introduction of fluid mechanics, ram pressure, jump conditions, shock frames of reference

High-energy astrophysics

a.    Supernova remnants: Free expansion, Sedov-Taylor phase, snowplough phase, merger with the ISM.

b.    Accretion physics: Eddington limit, Bondi-Hoyle accretion, steady thin accretion

c.    First and second order Fermi acceleration (diffuse shocks)

Multi-messenger astrophysics

Gravitational waves, basic physics from binary mergers, and cosmic rays.

To introduce a range of fundamental processes that contribute to the observed multi-frequency electro-magnetic and multi-messenger emission from astrophysical objects.  This largely relates to gas in the interstellar medium and high-energy astrophysical processes such as supernova explosions and accretion.  The astrophysical context will be introduced and connected to the key physics from the core curriculum.

On the successful completion of the course, students will be able to:  

ILO 1

Describe the sky as seen across the electromagnetic spectrum and non-photonic messengers and the involved radiation mechanisms

ILO 2

Explain fundamental physical processes in astrophysics such as

a.    radiative transfer

b.    shock waves

c.    accretion

ILO 3

Apply physical principles to predict the emission and absorption properties for atoms, molecules and grains in astrophysics contexts.

Two one hour, live in-person lectures per week where the core material with examples will be delivered. The recordings of these lectures will be on the course online page. A weekly problem sheet will be provided, with solutions and feedback on common problems released the following week.  A Piazza discussion forum is also provided where students can ask questions with answers provided by other students and the unit lead. 

Feedback will be offered to the cohort on the common difficulties on the weekly questions sheets, model answers will be issued.

Recommended texts  

Dyson, J.E. & Williams, D.A. The Physics of the Interstellar Medium (2nd ed.) (IOP Publishing)

Rosswog, S. & Bruggen, M. Introduction to High-Energy Astrophysics (CUP)

Supplementary reading

Draine, B.T., Physics of the Interstellar and Intergalactic Medium, (Princeton)

Longair, M. S. High Energy Astrophysics, 3rd edition, (CUP)  

Rybicki, G.B. & Lightman, A.P. Radiative Processes in Astrophysics