Disks and Accretion

Course manual 2020/2021

Course content

Accretion is the process by which stars and planets form and – when the central object is a black hole or neutron star – is the most efficient energy source in the universe. The energy is released as electromagnetic radiation with unique observational signatures and via powerful outflows and jets. In this course we will study the physics of accretion flows and learn about the different types of accreting objects and how their properties are interconnected by the accretion process, from stellar-mass black holes and neutron stars in binary systems, over young stars to the accreting supermassive black holes in active galactic nuclei. We will see how the observed properties of these extraordinary objects can be explained by accretion theory, and how the observations have also led to major advances in our understanding of the theory. The course will consist of lectures combined with general principles- and problem-solving tutorials aiming to provide a wide physical understanding and to train problem solving abilities related to accretion phenomena.

Study materials

Literature

• Frank, King and Rayne: 'Accretion Power in Astrophysics'

Syllabus

• Extensive course notes on the core material

Other

• Supplementary notes and research papers

Objectives

• explain and apply general physical principles of accretion.
• distinguish the characteristic physical processes in various accreting astrophysical systems.
• interpret observational data in terms of accretion theory.
• use the thin disk approximation to analytically connect physical quantities.
• list and explain the assumptions underlying analytic approaches and
• critically reflect on their validity for a given system.

Teaching methods

• Lecture
• Self-study
• Computer lab session/practical training

The course spans seven weeks with two lectures per week, Tuesdays and Wednesdays. In these sessions which will be in a classical lecture style, we will cover the background material and introduce all relevant physical concepts, if possible by looking at relevant examples. In addition to the lectures, there are two kinds of tutorial sessions: one on general principles and one on problem solving. Every week you will prepare a few homework assignments for the problem solving tutorials on Wednesdays.

Learning activities

Attendance

Requirements concerning attendance (OER-B).

Additional requirements for this course:

• The student may be absent in one out of six problem solving classes without impacting their grade.

Assessment

20% of the final grade will be due to graded homework assignments providing formative assessment.
5% of the final grade will depend on the quality of your peer assessment.
75% of the final grade will be due to the summative examination. 

Assignments

General principles assignments (non-graded):

During the tutorial, we will hand out “Questions of the week” covering the key concepts of the preceeding week. You will be given ample time to check your notes and answer on your own. Then we will discuss the topics with the group and the lecturer, making sure everyone understands what was covered in the lecture providing feedback. These questions will be similar to “part A” questions in the exam.

Problem solving assignments (graded):

In preparation for the tutorial, you will work on a few “exam level” problem sets as homework. You should submit your answers as a pdf file to Canvas, latest until the beginning of the tutorial (15:00). During the tutorial, you will exchange your answers with another student to check each others solutions (annotate the pdf). The TA will then control your checked problem sets again to determine your grades for this module. The solutions thus checked and annotated by your peer and the TA will be returned back to you as feedback. 

There will be six problem sets and we will take your best 5 sets contributing 20% towards your final grade. Since your answers need to be readable by your peers, we reserve the right to deduct points if your notes are sloppy or unreadable due to bad image quality. Please seriously consider using LaTex for this (a template is provided), it will make everyone's life easier!

You will also get points for good grading (on a scale of 0-1): each problem set accounts 1% towards the final grade. You will be awarded the point if you made a reasonable attempt including comments where necessary. Your best 5 gradings hence count 5% towards your final grade.

Fraud and plagiarism

The 'Regulations governing fraud and plagiarism for UvA students' applies to this course. This will be monitored carefully. Upon suspicion of fraud or plagiarism the Examinations Board of the programme will be informed. For the 'Regulations governing fraud and plagiarism for UvA students' see: www.student.uva.nl

Course structure

Timetable

The schedule for this course is published on DataNose.

Additional information

Recommended prior knowledge: Physics and astrophysics at the Bachelor level.

Contact information

Coordinator

• dr. Oliver Porth

Staff

• S.C. Selvi