AS4011 The Physics of Nebulae and Stars 1

Academic year

2025 to 2026 Semester 1

Further information on which modules are specific to your programme.

Key module information

SCOTCAT credits

15

The Scottish Credit Accumulation and Transfer (SCOTCAT) system allows credits gained in Scotland to be transferred between institutions. The number of credits associated with a module gives an indication of the amount of learning effort required by the learner. European Credit Transfer System (ECTS) credits are half the value of SCOTCAT credits.

SCQF level

SCQF level 10

The Scottish Credit and Qualifications Framework (SCQF) provides an indication of the complexity of award qualifications and associated learning and operates on an ascending numeric scale from Levels 1-12 with SCQF Level 10 equating to a Scottish undergraduate Honours degree.

Availability restrictions

Not automatically available to General Degree students

Planned timetable

11:00

This information is given as indicative. Timetable may change at short notice depending on room availability.

Module coordinator

Prof K Wood

Prof K Wood
This information is given as indicative. Staff involved in a module may change at short notice depending on availability and circumstances.

Module description

This module introduces the physics of astrophysical plasmas, as found in stars and interstellar space, where interactions between matter and radiation play a dominant role. A variety of absorption, emission, and scattering processes are introduced to describe exchanges of energy and momentum, which link up in various contexts to control the state and motion of the matter, to regulate the flow of light through the matter, and to impress fingerprints on the emergent spectrum. The theory is developed in sufficient detail to illustrate how astronomers interpret observed spectra to infer physical properties of astrophysical plasmas. Applications are considered to photo-ionise nebulae, interstellar shocks, nova and supernova shells, accretion discs, quasar-absorption-line clouds, radio synchrotron jets, radio pulsars, and x-ray plasmas. Monte-Carlo computational techniques are introduced to model radiative transfer.

Relationship to other modules

Pre-requisites

BEFORE TAKING THIS MODULE YOU MUST ( PASS AS2001 OR PASS AS2101 ) AND PASS PH2012 AND ( PASS MT2501 AND PASS MT2503 ) AND ( PASS PH3081 OR PASS PH3082 )

Assessment pattern

2-hour Written Examination = 75%, Coursework = 25%

Re-assessment

Oral Re-assessment, capped at grade 7

Learning and teaching methods and delivery

Weekly contact

3 lectures occasionally replaced by whole-class tutorials.

Scheduled learning hours

30

The number of compulsory student:staff contact hours over the period of the module.

Guided independent study hours

120

The number of hours that students are expected to invest in independent study over the period of the module.

Intended learning outcomes

  • Define and use the basic radiant quantities such as specific intensity, mean intensity, flux and radiation pressure of a radiation field, optical depth, photon mean free path, etc
  • Use the equation of radiative transfer to solve for simple geometries how the emergent intensity of a beam of radiation is modified by emitting and absorbing material along its path
  • Understand the basic physics of the development of HII regions: development of a Stroemgren sphere, the importance of ionization fronts, use the jump conditions to distinguish between R- and D-type fronts, and understand their importance in the evolution of an HII region
  • Distinguish between radiatively and collisionally induced transitions, and state their importance in relation to the global energy balance of a body of gas
  • Distinguish between HII region recombination-spectrum formation in Case A and Case B, and use Balmer-line fluxes and line ratios to determine total ionizing flux and interstellar extinction in Case B
  • Understand basic principles behind Monte Carlo radiation transfer scattering codes including sampling for direction of emission, optical depths, and scattering angles. Develop a Monte Carlo scattering code

Additional information from school

For guidance on AS and PH modules please consult the School Handbook, at https://www.st-andrews.ac.uk/physics-astronomy/students/ug/timetables-handbooks/