from The Open University
Alternatively you can skip the navigation by pressing 'Enter'.
Secret History Of... Deptford High StTuesday, 21st April 2015 20:00 - BBC FourHow did the "Oxford Street of South London" come to be one of the poorest shopping streets in modern London? Read more: The Secret History Of Our Streets - Deptford High Street
Secret History Of... Deptford High StWednesday, 22nd April 2015 02:00 - BBC Four
Thinking Allowed: The Ethnography Award winner 2015Wednesday, 22nd April 2015 16:00 - BBC Radio 4
Thinking Allowed: The Ethnography Award winner 2015Monday, 27th April 2015 00:15 - BBC Four
Thinking Allowed: The Ethnography Award 'Shortlist' 2015Available until Friday, 15th April 2016 10:30This week's Thinking Allowed hosts a special programme dedicated to academic research in ethnography. Read more: Thinking Allowed: The Ethnography Award 'Shortlist' 2015
A History of Ideas - Descartes Cogito Ergo SumAvailable until Thursday, 14th April 2016 08:30
A History of Ideas - Erving Goffman's Performed SelfAvailable until Thursday, 14th April 2016 08:15
Thinking Allowed: The Ethnography Award 'Shortlist' 2015Available until Friday, 15th April 2016 09:45
What does it mean to be me?Watch these short and snappy animations on the subject of me: the individual, memory, 'self' and... Watch now: What does it mean to be me?
Take the photographic memory testCan you capture scenes just by looking at them? Find out with our photographic memory test. Launch now: Take the photographic memory test
Introduction to bookkeeping and accountingThis free course Introduction to bookkeeping and accounting provides an introduction to the... Try: Introduction to bookkeeping and accounting now
English: skills for learning[BETA] This course is for anybody who is thinking of studying for a university degree and would... Try: English: skills for learning now
Introduction to active galaxies
The field of active galaxies is recognised as one of increasing importance. But how do...
The field of active galaxies is recognised as one of increasing importance. But how do we know there are different kinds of galaxy? What are active galaxies? How are they powered? This unit examines the different types of active galaxy and looks at the crucial role of the active galactic nucleus and the energy source at its heart.
By the end of this unit you should be able to:
- explain how and why the optical spectrum of an active or starburst galaxy differs from that of a normal galaxy;
- explain how and why the broadband spectrum of an active or starburst galaxy differs from that of a normal galaxy;
- describe briefly the observed features of starburst galaxies and the four main classes of active galaxies (quasars, radio galaxies, Seyfert galaxies and blazars);
- understand the evidence that indicates the presence of a compact active galactic nucleus (AGN) in active galaxies;
- explain why an AGN should emit broad lines, narrow forbidden lines and continuous radiation;
- give an account of an accreting massive black hole as the engine of the AGN and relate its luminosity to the mass accretion rate;
- outline some of the outstanding problems relating to the evolution of active galaxies.
- Current section: Introduction
- Learning outcomes
- 1 Overview
- 2 The spectra of galaxies
- 3 Types of active galaxies
- 4 The central engine
- 5 Models of active galaxies
- 6 Outstanding Issues
- 7 Unit Summary
Introduction to active galaxies
Active galaxies provide a prime example of high-energy processes operating in the Universe. This unit introduces the evidence for activity from the spectra of some galaxies, and the concept of a compact active galactic nucleus as a unifying model for the observed features of several types of active galaxy. It also develops the key skill of applying arithmetic and simple algebra to solving scientific problems.
This course is an adapted extract fromt he course