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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


See Astronomy master schedules

You will find the timetables for all courses and degree programmes of Leiden University in the tool MyTimetable (login). Any teaching activities that you have sucessfully registered for in MyStudyMap will automatically be displayed in MyTimeTable. Any timetables that you add manually, will be saved and automatically displayed the next time you sign in.

MyTimetable allows you to integrate your timetable with your calendar apps such as Outlook, Google Calendar, Apple Calendar and other calendar apps on your smartphone. Any timetable changes will be automatically synced with your calendar. If you wish, you can also receive an email notification of the change. You can turn notifications on in ‘Settings’ (after login).

For more information, watch the video or go the the 'help-page' in MyTimetable. Please note: Joint Degree students Leiden/Delft have to merge their two different timetables into one. This video explains how to do this.

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.

Reading list

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


From the academic year 2022-2023 on every student has to register for courses with the new enrollment tool MyStudyMap. There are two registration periods per year: registration for the fall semester opens in July and registration for the spring semester opens in December. Please see this page for more information.

Please note that it is compulsory to both preregister and confirm your participation for every exam and retake. Not being registered for a course means that you are not allowed to participate in the final exam of the course. Confirming your exam participation is possible until ten days before the exam.

Extensive FAQ's on MyStudymap can be found here.


Lecturer: Prof.dr. J.S. (Jelle) Kaastra
Teaching Assistants: Zhenlin Zhu, Chen Li


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