NFYB19001U Extragalactic Astrophysics (Astro4)

Volume 2021/2022

BSc Programme in Physics


Presentation of basic astrophysical concepts. Quantitative understanding of the correlation between observations and thery. Basic understanding of the structure, formation, evolution and dynamics of galaxies. 

Elementary use of Python programming for plotting and calculations for project work in the course.

Topics: spiral galaxies, elliptical galaxies, active galaxies, starburst galaxies, galaxy structure and dynamics, formation and evolution of galaxies, galactic clusters and groups, distances to galaxies and large scale structure of the universe, galaxies in the early universe.

Learning Outcome


  • can confidently use the connections between apparent magnitude, absolute magnutude, colour and distances.
  • has confident use of the virial theorem.
  • can write simple programs in python for reading and plotting tables and spectral data as well as conduct calculation with these.
  • can process astronomical spectra with the purpose of building spectral models of galaxies, account for and assess the possibilities and limitations of these models.
  • can use the virial theorem for determining the masses of galaxies and galactic groups/clusters.
  • can use scientific knowledge of galaxies and their constituents for discussing and justifying the strategy for project work in the group, as well as using the group work and problem calculations to obtain new knowledge.



  • can account for the determination of physically observed parameters such as velocity dispersion, Sersic index, surface brightness, rotational velocity, scale height, scale length etc. in a confident and critical manner can account for how basic observational data are obtained and how the structural parameters of galaxies are derived from these.

  • can account for the Tully Fisher relation for spiral galaxies and the fundamental plane for elliptical galaxies, their uses and how the underlying data is obtained.

  • can account for simple models for chemical enrichment including critical discussion of the basic assumptions.

  • presents clear knowledge and understanding of strong encounters, weak encounters and the meaning of these in astrophysical systems, and galactic interactions.

  • can give an overall description of the most important basics of Galactic formation and evolution.

  • can account for how rotation curves can be used to derive the existence of dark matter, including how the underlying data is obtained.

  • can account for the origin of the observed radiation from quasars over all of the electromagnetic spectrum.

  • can give a superior description of the unified model for active galactic nuclei and the observational evidence in support of them.

  • can account for how the Lyman Alpha forest is formed in spectra of distant astrophysical objects.

  • can account for the appearance of the spectra of different galaxy types (spiral, elliptical, starburst and AGN) in a critical manner.

  • can identify an elliptical galaxy, a spiral galaxy, a starburst galaxy and AGN based on their images and spectra as well as explain the physics behind their observed properties.

  • can account for the current methods for mass determination of galaxy groups and clusters as well as for the physics behind their observed properties and the properties of their constituent galaxies.

  • can account for the observed properties of the large scale structures, the underlying physics, and the potential effects that can influence our measurements and mapping of these, with special focus on redshift surveys and correlation functions.

  • in a critical manner can account for the constituents of galaxies, their basic dynamics and the relative contribution of star populations between different galaxy classes.

  • can in a critical manner account for methods for determining mass and distance for the first and the following steps on the cosmic distance ladder.


The course gives the students a background for understanding the basic challenges of studying galaxies and their cosmic evolution, which can be used in subsequent M.Sc. level astrophysics courses, projects as well as discussion fora for new journal papers in topics of general relevance for extragalactic astrophysics.

The student will develop skills in Python programming, which may serve as tools for subsequent M.Sc. level astrophysics courses and projects at both B.Sc. and M.Sc level.

Through the course, the student will see how knowledge obtained in previous and parallel basic physics courses can be used in a specialised topic such as astrophysics.

See Absalon for course litterature.

Examples of course literature: course book (e.g. the latest edition of "Galaxies in the Universe. An Introduction", Linda S. Sparke and John S. Gallagher, Cambridge University Press) in combination with lecture notes, project reports, computer exercises, problem solutions, quizzes, and selected scientific articles.

Students are required to have knowledge in basic physics, including mechanics, electromagnetism, thermodynamics, as well as mathematics equivalent to first 2 years of university studies. The course also prerequisites knowledge in basic astrophysics at a university introductory level, as well as more detailed knowledge about stars and planets. Besides, it is an advantage to have basic knowledge in computer programming.
Classes/discussions, quizzes, group Work, group Projects, problem sessions and computer exercises.
It is expected that the students bring their own laptops.
The following terminal software is needed:
Windows: installation of Python.
Linux: X11 user interface is standard and runs automatically.
MacIntosh/MACs: From medS OS 10.5 up the X11 user interface can be used. It can be downloaded for free from http:/​/​​landing/​.
  • Category
  • Hours
  • Class Instruction
  • 42
  • Preparation
  • 103
  • Exercises
  • 20
  • Project work
  • 40,5
  • Exam
  • 0,5
  • Total
  • 206,0
7,5 ECTS
Type of assessment
Oral examination, 25 minutes
no preparation time
Exam registration requirements

Full participation in at least 50% of the course quizzes given in Absalon before each problem session (i.e. all questions must be answered) as well as one computer exercise report that needs to be approved for participation in the exam. It will be possible to re-submit a report that was not approved.

Only certain aids allowed

At the oral exam, the student may bring a single page disposition for each exam question (the questions are known beforehand) with keywords and one or two formulas (i.e. not closely filled) for support. The student may refer to figures in the text book.

Marking scale
7-point grading scale
Censorship form
No external censorship
several internal examiners

Same as regular exam.

The exam registration requirement is the same as for the ordinary exam. Any approved problems/reports may be re-used, but the student can also choose to re-submit. The registration requirement must be fulfilled two weeks prior to the re-exam.

If the requirement for 50% participation in the quizzes that were given before the problem sessions was not fulfilled at the regular exam, the student must in stead submit 3 problems for approval. These must be approved three weeks prior to the re-exam.

Criteria for exam assesment

see learning goals