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High-energy Astrophysics


Admission Requirements



This course discusses high-energy astrophysics. High-energy processes are ubiquitous in the Universe. X-rays are emitted or absorbed by a broad range of sources ranging from the solar system, stars, the interstellar medium, compact black hole environments and active galactic nuclei to clusters of galaxies and the diffuse gas of the cosmic web.

Two main topics form the core of this course:

  1. The production mechanisms of thermal X-ray emission in a broad range of environments, ranging from collision-dominated plasmas to photo-ionized gas.
  2. Accretion processes onto compact black holes: accretion disks around supermassive black holes and the X-ray radiation in that environment.

During the course, several real-life practical examples from the most recent and ongoing work in this field will be presented. Lectures and an obligatory computer class form the core of the course. The lecture notes contain exercises that can be made at home to test the understanding of the course material. There is no homework for the computer class.

Course objectives

After completion of this course, you will be able to summarize various aspects of high-energy sources in the Universe.

This means that after this course you will be able to:

  • Classify and characterize X-ray spectra of a broad range of cosmic X-ray sources according to the dominant physical processes

  • Make exercises on the physical processes that contribute to X-ray emission

  • Quantitatively describe the structure and spectra of accretion disks in their basic form

  • Analyze and summarize scientific papers on X-ray emission and accretion processes

  • Analyze and interpret complex X-ray spectra through the experience gained from the computer course

Soft skills

In this course, you will be trained to:

  • Master a new field (high-energy astrophysics)

  • Plan to make exercises in due time to keep-up with the course

  • Analyze real data and the practical nuisances that come with real-life data

  • Write a report on the analysis of a real-life observation


See Astronomy master schedules

Mode of instruction

  • Lectures

  • Exercise class (obligatory computer class)

Assessment method

Finishing the computer class and delivering the report is obligatory to take the written exam. For a retake exam, the results of the computer class will remain valid. No retake of the computer exercise is possible.


Brightspace will be used to communicate with students and to share lecture slides, homework assignments, and any extra materials. To have access, you need a student ULCN account.

Reading list

Lecture notes and all other course material will appear online at the homepage of the lecturer.


Via uSis. More information about signing up for your classes can be found here. Exchange and Study Abroad students, please see the Prospective students website for information on how to apply.

Contact information:

Lecturer: Prof.dr. J.S. (Jelle) Kaastra