Extrasolar Planets

Extrasolar Planets and Astrophysical Discs
ASTM735/MTH735U

Lecturer: Prof. Richard Nelson
Office: 214 in the G.O. Jones building
Extn: 3460
Email: R.P.Nelson@qmul.ac.uk
Lecture Times: 18:30 - 20:45 on Thursdays, January - March 2012
Lecture Room: M103 in the School of Mathematical Sciences

Aims:
To provide students with an understanding of the observations and physics of accretion discs in a broad variety of astrophysical settings, including protoplanetary discs, discs in close binary systems, and discs around massive black holes.
To provide students with an understanding of the statistical, physical and orbital properties of extrasolar planets, and the methods used to detect planets outside of the Solar System.
To describe theories of the formation of planetary systems using basic physical principles and models of protoplanetary discs. To understand basic ideas about the origin of life, and its possible existence outside the Solar System.

Learning outcomes:
Students should:

Understand the roles that accretion discs play in a broad range of astrophysical phenomena including protostars, close binary systems, and massive black holes, and be able to describe observational evidence of these phenomena
Understand theoretical models of accretion discs based on basic physical and mathematical principles. Be able to derive equations for accretion disc evolution, and perform calculations relating to their physical properties
Have a broad understanding of the statistical and physical properties of the extrasolar planets, and the observational methods used to determine these
Understand how physical principles and simple models of protoplanetary discs can be used to develop theorise of planetary formation, and be able to describe current thinking about how planetary systems form
Be able to describe physical conditions thought to be necessary for the emergence of life, and current ideas about how life came into being

Books: There are no books that provide complete coverage for this course. However the most comprehensive textbook on accretion discs is `Accretion Power in Astrophysics' by Juhan Frank, Andrew King, and Derek Raine, published by Cambridge University Press.

The lectures will be organised as follows:

Lecture 1:
Introduction to the role of angular momentum in astrophysics.
Phenomenological description of astronomical objects in which differentially rotating systems are found (accretion discs, planetary rings, galactic discs, planetary systems).
Rotation laws and balance between centrifugal and gravitational forces.
Equations of motion for self-gravitating, magnetised, inviscid fluid will be introduced.
The virial theorem for rotating, magnetised fluid masses.

Week 1 lecture notes (pdf file)

Lecture 2:
Protostellar disc formation via cloud collapse, including criteria for collapse of molecular clouds, and estimates of disc sizes.
Comparison with observations.
Disc formation in close binary systems.
The Roche potential.
Classification of semi-detached binary systems in which discs form (cataclysmic variables, low-mass X-ray binaries, X-ray binaries).
Close binary formation scenarios, and Roche lobe overflow.
Orbital evolution due to mass transfer.
Disc sizes and requirement for compact objects.
Observations of C.V. discs and dwarf novae outbursts.

Week 2 lecture notes (pdf file)

Notes on orbital evolution and mass transfer (pdf file)

Lecture 3:
Accretion onto compact objects as powerful energy sources.
Angular momentum transfer mechanisms in differentially rotating discs.
Viscosity, global magnetic fields and disc winds, wave transport through tidal interaction.
Vertical structure and hydrostatic equilibrium.
Derivation of diffusion equation for surface density evolution.
Time scales for viscous evolution, and requirement of anomalous viscosity in discs.

Week 3 lecture notes (pdf file)

Lecture 4:
Steady state disc theory.
Energy production in discs and viscous dissipation as energy source.
Temperature profiles in steady state discs.
Application to protostars, C.V.s, X-ray binaries, and active galactic nuclei.
Eddington limited accretion.

Week 4 lecture notes (pdf file)