Astronomy 822: ELECTROMAGNETIC RADIATION
Autumn 2002
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Welcome to the Astronomy 822 course! The objective of the course is
to provide the student with a working knowledge of basic electromagnetic
processes related to the generation, propagation and scattering of
radiation in astrophysics, sufficient to understand publications and
embark on current research. We will deal specially with continuous
spectra. We will discuss some of the most important applications
to astrophysics.
Textbook
George B. Rybicki & Alan P. Lightman, Radiation Processes in Astrophysics
(John Wiley, 1979).
I may also assign some readings from papers or other books during the
course to complement our main textbook (which is very good in explaining
the theory, but does not generally go into applications of the physical
concepts to real astrophysics).
Other complementary books:
- "Galactic and Extragalactic Radio Astronomy", G. L. Verschuur, K. I.
Kellermann (Springer-Verlag).
- "High-Energy Astrophysics", M. Longair.
- "Quasars and Active Galactic Nuclei", A. K. Kembhavi, J. V. Narlikar
(Cambridge University Press.
Homework
This course will be based a lot on homework, I will assign roughly one
every week. Someone has said that the definition of understanding
the concepts is if you can use them to solve problems. In addition to
the homework that you will have to hand in, you
should also read the homework problems in the book that I will assign
in class, and think how you would solve them. If you are not sure you
know how to solve them, be sure to read and understand the solution
(these are given in the back of the book).
Exams
There will be a short midterm exam that will consist of a number of key
terms that have come up in the course, for which you will need to provide
a brief definition. This exam will be closed book. I will ask you to
write similar definitions in some of the homeworks so that you get some
practice on it.
The final exam will have two parts. The first will be also short, in-class,
and just like the midterm. The second part will be take-home, using books
or notes, and will have
problem sets similar to the ones you will do in the homework.
Grades
The final grade of the course will be determined as:
- Homework: 50%
- Midterm: 10%
- Final Exam, Part I (like midterm): 15%
- Final Exam, Part II (like problem sets): 25%
Assigned reading
Assigned reading will be announced in class and posted on this
website. You should complete the reading by the due date so that you
can come to class prepared with any questions you want to ask.
Office Hours
Because we are all around most of the time, I will have no official office
hours, you are welcome to ask questions in my office any time you wish.
If you don't find me, you can contact me by email to set up a time to meet.
It is important that you ask questions, either in class or in my office,
when there is something you don't understand. If you feel lost on the homework,
do not give up or feel frustrated, I will be able to help you understand
with what you feel confused about. It is always good that students can
learn from each other, so students are welcome to discuss the homework
among them. However, they should not copy the solution from each other.
Once you've been helped to understand how to solve the problem, you should
then go and do it yourself.
We will be doing the subjects listed below, essentially covering chapters
1 through 8 in the textbook. For each topic I will list the sections you
should read, the homework problems that you should check you know how to
solve (and consult the solutions carefully if you don't), and the date by
which you should have completed this. I will write these dates as the
course proceeds, allowing flexibility for the pace of the course. I may
occasionally add additional reading from other books or papers. The
most important thing is that we cover the material sufficiently well so
that everybody understands it; we can slow down if we must even if that
means that we will not have covered every topic by the end of the course.
1. Flux and surface brightness. Radiative transfer. Blackbody radiation.
Sections 1.1 to 1.5
Problems: all from 1.1 to 1.6
Complete by 9/26
2. Einstein coefficients.
Sections 1.6 and 1.7.
Problems: 1.7, 1.8, 1.9.
Complete by 10/1.
Additional optional reading: For a good review of how astronomical masers
work, see the article by M. J. Reid and J. M. Moran in chapter 6 of
Verschuur and Kellermann,
3. Review of Maxwell's equations.
Chapter 2, all sections.
Problems: all from 2.1 to 2.4
Complete sections 2.1 to 2.4 by 10/3, sections 2.5 to 2.6 by 10/8.
4. Lienard-Wiechert Potentials. Dipole approximation. Multipole Expansion.
Sections 3.1 to 3.3
Problems: 3.1, 3.3, 3.7.
Complete by 10/10
5. Thomson scattering. Application: cosmological optical depth to electron
scattering.
Sections 3.4, 3.5, 3.6
Problems: 3.2, 3.4, 3.6.
Complete by 10/15
6. Review of relativity. Doppler effect, light aberration,
transformation of intensity.
Sections 4.1 to 4.3
Problems: 4.1, 4.2, 4.4, 4.7, 4.8.
Complete section 4.1 by 10/17, sections 4.2 to 4.3 by 10/22
7. Electromagnetic tensor. Field transformations. Uniformly moving charge.
Sections 4.4 to 4.7
Problems: 4.9, 4.10, 4.15, 4.16.
Complete by 10/24
8. Emission from Relativistic Particles.
Sections 4.8, 4.9
Special assigned reading:
Paczynski, B. 1996, ApJ, 308, L43:
Gamma-ray Bursters at Cosmological Distances.
Problems: 4.12, 4.13, 4.14.
Complete by 10/29
9. Free-free emission. Spectra of X-ray clusters.
Sections 5.1, 5.2, 5.3
Problems: 5.1, 5.2.
Complete by 11/5
10. Synchrotron Radiation: Spectrum, self-absorption. The Compton catastrophe.
Problems: 6.1, 6.2, 6.3.
Complete by 11/7
Check out the radio image around the M87 Galaxy observed with the
Very Large Array . A nice example of synchrotron emission from a jet.
Check out Bill Keel's page on
Quasar and Active Galaxy images
, for example the image of the jets and radio lobes of
Cygnus A .
11. Compton scattering. Applications: the y-parameter distortion, the
Sunyaev-Zeldovich effect, Compton drag, Compton cooling.
Problems: 7.1, 7.3.
Complete by 11/19
Section 7.6 in RL.
Application to the Sunyaev-Zeldovich effect: see
"Principles of Physical Cosmology" (P. J. E. Peebles): pages 581-588,
and 603-608; or Cosmological Physics (J. A. Peacock), pages 375-377.
Complete by 11/26
12. Plasma effects: Dispersion, Faraday rotation.
Problems: 8.1, 8.2.
Complete by 12/3
Homework:
Where to find me:
Astronomy 822 Autumn Quarter 2002
TR 1:30-3:00pm McPherson Room 4045
Jordi Miralda-Escudé
Astronomy Department
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