Radiation and Matter (VS1) (U02595)

? Credit Points : 10 ? SCQF Level : 11 ? Acronym : PHY-4-VRadMatt

We start by learning the physics of radiation and its quantal interaction with matter, then go on to study this interaction in various astrophysical environments to define the nature and limitations of observation. Finally we apply these techniques to several important and characteristic astronomical observations, such as the 21cm radiation of atomic hydrogen used to weigh galaxies, the carbon monoxide emission used to map star nurseries, and the hydrogen Lyman alpha line forest used to determine the distribution of galaxy-forming matter throughout the Universe.

Entry Requirements

? This course is only available to part year visiting students.

? This course is a variant of the following course : U01439

? Pre-requisites : Year 3 Astrophysics, or equivalent.

Subject Areas

Home subject area

Undergraduate (School of Physics), (School of Physics, Schedule Q)

Delivery Information

? Normal year taken : 4th year

? Delivery Period : Not being delivered

? Contact Teaching Time : 2 hour(s) per week for 11 weeks

All of the following classes

Type	Day	Start	End	Area
Lecture	Monday	10:00	10:50	Other
Lecture	Thursday	10:00	10:50	Other

Summary of Intended Learning Outcomes

Upon successful completion of the course, students should be able to:
1)write Maxwell's equations, demonstrate that these can be expressed gauge covariant potentials; show that they lead to definitions of energy density and flux in the radiation field, outline derive the wave equation for the potential;
2)write the solution to the wave equation, demonstrate that in the wave zone it consists of spherical waves with 1/r amplitude dependence and speed c, and give the explicit results for point charges from which field and flux are derived;
3)apply these results to simple examples;
4)describe the free electromagnetic field in terms of SHM modes;
5)by comparison with quantized SHM, describe the properties of photons;
6)describe the nature of gauge invariance in wave functions and electromagnetism, and hence derive the interaction Hamiltonian; use Fermi's golden rule to give the transition rate;
7)(with guidance) derive the dipole transition rate and outline those for magnetic dipole and electric quadrupole;
8)be able to calculate intensity and flux density from a uniform source in terms of its density and temperature, and of the transition rates and collision cross sections;
9)be able to calculate and explain the appearance of emission and absoption lines in terms of optical depth and the above local physical properties of the source;
10)understand and be able to derive in outline a variety of astronomically important examples of line emission and absorption - in particular the Lyman alpha and 21cm lines of H, the rotational emission from CO and the diagnostics of temperature and density obtainable from fine structure transitions in oxygen (and other) ions;
11)be able to apply these techniques to predict and interpret observational results in a variety of simple cases involving line emission and absorption.