Active Galactic Nuclei and Black Holes (assistent's website)

Description

In this lecture series some basic physical processes important for the physics of active galactic nuclei (AGN) and black holes are presented. There will be a general introduction to the classification and observation of active galaxies and a discussion of individual elements characterizing an AGN, such as black holes, relativistic jets, and accretion disks.

Teachers

Lectures:

Prof. Dr. Heino Falcke Scientist in the VLBI Group of the Max-Planck-Institute for Radio-astronomy (MPIfR) in Bonn (Germany) and `bijzonder hoogleraar' in High-Energy Astrophysics at the University of Nijmegen. For more information visit his course website (German) (where most of this information is taken from).

Tutorials (werkcolleges):

`Teaching Assistant' for the tutorials: Wilbert van Ham.

Lectures

The transparencies used in the lectures can be found at Heino Falcke's website or below.

1.	Introduction to AGN	pdf-file
2.	Relativistic Jets and Compact Radio Cores (2)	pdf-file
3.	Synchrotron Radiation	pdf-file
4.	Shock Acceleration	pdf-file
5.	Black Hole Basics	pdf-file,
6.	Standard Accretion Disks	pdf-file
7.	Advection-Dominated Accretion Flows	pdf-file
8.	The Emission-Line Region of AGN	pdf-file
9.	A unified view of AGN	pdf-file

Tutorials (werkcolleges)

Tutorial 1:

look up the DRAGN atlas and identify the radio galaxies as either FRI or FRII galaxies. Check your results with the identifications on the corresponding site by clicking in the list or in the article: `Bright radio sourses at 178 MHZ: flux densities, optical identifications and the cosmological evolution of powerfull radio galaxies' by R. A. Laing et al. MNRAS 1983.
Look up the article `A search for dwarf Seyfert nuclei. II, an optical atlas of the nuclei of nearby galaxies' by Ho, L.C., Filippenko, A. and Sargent, W. L. W. Part 2. In this atlas of 486 spectra try to find 5 Seyfert I galaxies (the rarest type in nearby galaxies), 5 Seyfert II galaxies and 5 LINER galaxies, using the selection criteria given in the table below. A summary of the data can be found here. The answers can be found here.

Type	[OIII]/Hβ	[OI]/Hα	[NII]/Hα	[SII]/Hα
HII	any	<0.08	<0.6	<0.4
SI	>3	>0.08	>0.6	>0.4	broad (typically 75 Angstrom at 4500 Angstrom) and narrow (typically 6 Angstrom at 4500 Angstrom) emission lines
SII	>3	>0.08	>0.6	>0.4	only narrow lines
LINER	< 3	>0.17	>0.6	>0.4

You can find the wavelength of these lines in one of the figures in the lecture notes. Verify your results using Part 4 of the article mentioned above.

Tutorial 2:

Getting started: In your home directory, make a directory called `agn'. Check wether your system has a C compiler and a plotting program by typing the shell commands:
- > which gcc or
- > which cc and
- > which gnuplot.
Have a look at Peter Klok's C course or some other C course to get started. To get a working program give the command:
- > gcc <file.c> -o <file> -lm
where the last options tells the compiler to link with the math library.
Getting serious: As the first two step to compute the entire disk spectrum,
- first make a working C program that calculates the Planck spectrum or black body spectrum for one particular temperature. The program should calculate the value of F_nu; for a wide range of ν's (for instance 10⁴Hz to 10¹⁶Hz: figure out how to do this in a smart way, without needing 10¹² iterations in your loop!), write the results to a data file, and finally produce a clear plot (in for instance GNUplot) with title, labels on the axes etcetera. Don't forget the units. I want to see ergs, seconds, centimeters etcetera, not the unitless stuff.
- secondly, in the same way write a program that calculates the temperature at different radii, using the formula derived in the lecture. Again conclude with making a nice plot with labels ande units.
Finally: using your experience from the last two exersises, combine these to calculate the integrated spectrum of the entire disk, by integrating the temperature structure over the disk at each frequency (of you BB-spectrum). Save the 3 programs and the 3 plots as the `exam' of this tutorial.

Tutorial 3:

Tutorial 3

Tutorial 4:

Tutorial 4

Tutorial 5 (2006-01-09, last tutorial):

This is a practical continuation of tutorial 2. There we calculated the spectrum of a black body and of an accretion disc. Now we will fit these spectra to some measured spectra.

MRK 273
MRK 586
MRK 335
3C 273

Find the spectra. Convert them to some suitable data file format. If you can't find the data itself, extract it from graphs in articles with for instace the Dexter tool, available at Sourceforge. First fit the accretion disc. Then add 1-3 black bodies and fit the total.

Schedule

Exam & Grading

The grading of the course will be based on the participation in the lectures, the programs written in the tutorial sessions and a short presentation in class. The exact weighting of these sub-divisions still has to be decided.