## First-year PhD Astrophysics Reading Group, 2007 version |

Astrophysics is a huge and diverse discipline. Nevertheless, there is a body of knowledge, ideas and jargon that should really be familiar to everyone, whatever their detailed field of research. In the space of a 3-year PhD, getting to grips with this material is not easy, but it is important to get at least some feel for the basics early on.

Therefore, we will be having a crash course that attempts to get through the most important topics in a concentrated burst at the start of the PhD. The idea is that the first-year students plus moderator(s) will meet regularly to discuss the material on the reading list below. This is like the fabled Kamikaze system, in that the sessions will be interactive discussions - no sitting back and passively absorbing (or not) lectures. In order to stimulate this attitude of engagement, there will be a weekly problem for which everyone should hand in a written answer.

However, the difference is that complete mastery of all the details is not expected. This is the real world: the material is out there, and professional astrophysicists have to develop a working familiarity with it - often in far less time than would be ideal. At the most basic level, this means being able to decode the jargon. With luck, the ideas will be sufficiently exciting that readers will be motivated to dig into the details of some derivations. In coming together and talking over the material, it should be possible to share these insights. The main thing is to cover the territory as thoroughly as possible given the limited time (as a guide, it is envisaged that all preparation for the groups should not take a majority of your time - say up to 1 working day total per tutorial). This will at least provide an introduction to some of the more useful textbooks, and lay the foundation for more detailed specialized study.

Avalable in reference section of ROE library. Please xerox the relevant bit and leave the book for others to use. There are plenty of alternatives; reading these as well is not forbidden.....

Binney & Merrifield, Galactic astronomy

Dyson & Williams, The physics of the interstellar medium

Jackson, Classical electrodynamics (3rd [SI] edition)

Lena, Observational astrophysics

Longair, High-energy astrophysics (2nd edition: 2 vols)

Peacock, Cosmological physics (apologies...)

Phillipps, The physics of stars

Press et al., Numerical recipes (2nd edition)

Rybicki & Lightman, Radiative processes in astrophysics

It is easy enough to convince yourself that you understand a piece of reading, but the acid test is to use the material. Therefore, so that everyone can gauge for themselves whether the reading is sinking in, there will be a series of questions associated with the group, at a frequency of roughly one per week. These were originally classed as "hand-in" to force people to try them; but this is a bit artificial, since they are not marked. We therefore have an honour system, where students are expected to make an independent effort to produce a full written solution to the problem that goes with a given piece of reading. Possibly you will fail - in which case come to the tutorial with some relevant points in mind that you want to see clarified. If you still can't do the problem afterwards, even after some discussion with other students, you should bring your partial solution to the relevant tutor and ask for advice. But most of the time, the problems should get solved without the need for formal scrutiny.

The list of questions may be subject to change as the sessions progress.

Subject to change as the sessions progress. Name of the tutor for a given session is in [brackets].

Date: October 4 [JAP]

Topic: Radiation basics

Jargon: specific intensity; surface brightness; Planck function;
Einstein coefficients; radiative transfer; optical depth; scattering; extinction

Reference: Rybicki & Lightman p1-39

Date: October 11 [PNB]

Topic: Astronomical measurements

Jargon: Celestial coordinates; parallax; proper motion; magnitudes; colours; K-corrections

Reference: Binney & Merrifield p26-61

Date: October 18 [ERT]

Topic: Astronomical signals

Jargon: Fourier transform; sampling; Nyquist frequency; aliasing;
convolution; FFT; filtering; signal-to-noise

Reference: Press p490-499 and 530-535 (Fortran edition. Add about 7 pages for the C edition);
Lena p81-95 and p116-140

Date: October 25 [AFH]

Topic: Telescopes

Jargon: diffraction limit; wavefront; pupil; adaptive optics; interferometry;
uv plane; aperture synthesis

Reference: Longair Vol 1 p216-236; Lena p218-262

Date: November 1 [JAP]

Topic: Detectors and spectrographs

Jargon: shot noise; dark current; flat field; background limit;
noise temperature; brightness temperature; diffraction grating; blaze

Reference: Longair Vol 1 p237-260; Lena p274-308

Date: November 8 [IPRN]

Topic: Statistics and data modelling

Jargon: distribution function; central limit; variance;
standard error; skewness;
chi-squared; KS test; correlation; rank test;
maximum likelihood; covariance matrix; confidence limits

Reference: Press p603-619, p630-635, p650-662, 684-693
(Fortran edition. Add about 7 pages for the C edition);
Lena p96-115

Date: November 15 [JAP]

Topic: Matter & radiation

Jargon: ideal gas; degeneracy pressure; radiation pressure; Saha equation

Reference: Phillips ch2

Date: November 22 [JAP]

Topic: Astrophysical plasmas

Jargon: Plasma frequency; flux freezing; Alfven waves; Faraday rotation

Reference: Rybicki & Lightman p224-231; Jackson p319-322; Longair Vol 1 p307-312

Date: November 29 [ERT]

Topic: Bremsstrahlung

Jargon: Gaunt factor; free-free emission and absorption; cooling function

Reference: Longair ch3; Rybicki & Lightman p155-162

Date: December 6 [AFH]

Topic: Synchrotron radiation

Jargon: gyrofrequency; relativistic beaming; polarization; self-absorption

Reference: Longair ch18; Rybicki & Lightman p167-175

Date: December 13 [JAP]

Topic: Comptonization

Jargon: Compton and inverse Compton scattering; synchrotron self-compton; Kompaneets equation; SZ effect

Reference: Longair ch4; Rybicki & Lightman p195-216

Date: January 10 [JAP]

Topic: Line radiation

Jargon: recombination; forbidden lines; critical density; ionization parameter;
doppler width; voigt profiles; curve of growth

Reference: Rybicki & Lightman ch10; Peacock p361-365 and 429-430

Date: January 17 [WKMR]

Topic: Star-forming regions

Jargon: outflows; ambipolar diffusion

Reference: Dyson & Williams ch8

Date: January 24 [PNB]

Topic: Energy generation & transport in stars

Jargon: pp chain; CNO cycle; Gamow peak; opacity

Reference: Phillips ch4

Date: January 31 [PNB]

Topic: Stellar structure and evolution

Jargon: hydrostatic equilibrium; virial theorem; radiative diffusion; main sequence

Reference: Phillips ch5; Longair Vol 2 p52-91

Date: February 7 [ERT]

Topic: Gas dynamics and shocks

Jargon: shock adiabat; compression ratio; isothermal shocks; collisionless shocks; similarity solutions

Reference: Dyson & Williams ch6

Date: February 14 [RJM]

Topic: Active galaxies

Jargon: Seyferts; UVX; blazars; broad and narrow lines; superluminal motion; unification and tori; Magorrian relation

Reference: Peacock ch14

Date: February 21 [RJM]

Topic: Accretion

Jargon: thin disks; accretion efficiency; Eddington limit

Reference: Longair ch16

Date: February 28 [ANT]

Topic: Observational cosmology

Jargon: RW metric; comoving distance; Friedmann equation; density parameter; luminosity distance

Reference: Peacock p65-92