Syllabus

Scope and Spirit of the Course

ASTRO-502 is a lecture course on physical processes in astrophysical plasmas, culminating in radiation processes. It is geared towards junior astronomy graduate students and aims to cover a wide variety of topics that are generally useful in many areas of astrophysics (e.g., special relativity, electrodynamics, statistical mechanics). Applications include but are not limited to calculating the radiative power of astrophysical plasmas, the properties of the emerging spectra, and the cooling time of the plasma.  The topics will be covered at a fairly advanced level and substantial background will be needed. The course will emphasize analytic calculations of emission rates and spectral properties. Homework assignments will be an integral part of the course and an important tool of instruction. 

Upon successful completion of this course, the students will:

The topics will be covered at a fairly advanced level and substantial background will be needed. The course will emphasize analytic calculations of the radiative processes at work in hot astrophysical nebulae and hot plasmas. Homework assignments will be an integral part of the course and an important means by which the students will learn the basic principles of radiation processes and how to apply these principles to astrophysical nebulae and plasmas.

Textbooks and Summary of Topics Covered in This Course

There is no required textbook for this course. Most (but not all) of the material on radiation processes is drawn from the two textbooks below; but keep in mind that the course content is defined by what is presented in class, not by the textbooks. The first of the two books, by Rybicki & Lightman, has been placed on reserve in the Physical and Mathematical Sciences Library (PAMS library, 201 Davey Lab). The second of the two books, by Ghisellini, is available electronicall through the Penn State Libraris.

“Radiative Processes in Astrophysics,” by G. Rybicki & A. P. Lightman (1979, 2004 Wiley) Call Number: QB461.R88 2004. [Abbreviation: R&L] On reserve in PAMS library, 201 Davey.
A substantial fraction of the material in this course in drawn from this textbook. You will sometimes be asked to refer to equations or figures from this textbook.

“Radiative Processes in High-Energy Astrophysics,” by G. Ghisellini (2013, Springer).  This book is available electronically. You will be asked to log in with your PSU credentials to access it.  [Abbreviation: GG]

The following are useful but more advanced or specialized textbooks. We will refer to them selectively. A lot (but not all) of the material on hydrodynamics is drwan from the first two textbooks below, by Spitzer and Shore.

“Physical Processes in the Interstellar Medium,” by Lyman Spitzer Jr. (1978, reprinted in 2004 by Wiley, paperback). Call Number: QB790.S67 1998. [Abbreviation: Spitzer]

"Astrophysical Hydrodynamics" by Steven N. Shore (2nd edition, 2007, Wiley). Call number QB461.S446 2007. [Abbreviation: Shore]

“The Physics of Astrophysics, Vol 1: Radiation” by F. Shu (1991, University Science Books). Call Number: QB461.S58 1991 v.1. [Abbreviation: Shu]

“Theoretical Astrophysics, Vol 1: Astrophysical Processes” by T. Padmanabhan (2000, Cambridge University Press). Call Number: QB461.P33 2000 v.1. This book is also available electronically. You will be asked to log in with your PSU credentials to access it.  [Abbreviation: Padmanaban]

"Plasma Physics" by Peter A. Sturrock (1994, Cambridge University Press). Call number: QC718.S76 1994. This book is also available electronically. You will be asked to log in with your PSU credentials to access it.  [Abbreviation: Sturrock]

"Classical Electrodynamics" by J. D. Jackson. Call number QC631.J3 1999.  [Abbreviation: Jackson]

"Essential Radio Astronomy" by  J. J. Condon and S. M. Ransom, Web Course (NRAO Charlottesville)  [Abbreviation: C&R]

The first half of the course covers much of the background that is necessary in order to develop the theory of radiation processes. That includes basic physics, such as electrodynamics, special relativity, and statistical mechanics. Included is also an introduction to radiative transfer. The second half of the course covers continuum radiation processes, most of which are applicable to hot astrophysical plasmas. In the final two to three weeks the course covers elements of plasma physics, propagation of electromagnetic waves in plasmas, and basci hydrodynamics and shocks. If time permits the course will also cover hydromagnetic waves.  A detailed list of topics is given on the topics page of this web site. 

Expected Background

Students should be familiar with the following topics: elementary kinetc theory, basic properties of Fermions and Bosons, basic properties of the Planck function and blackbody radiation, basic properties of electromagnetic waves, basic particle kinematics and mechanics in special relativity. Students should also be able to solve simple differential equations and be familiar with the solutions of the well-known differential equations of mathematical physics (e.g., the wave equation and the Schroedinger equation).

Class Web Site and Canvas Page

On this web site you will find the syllabus (this page), the topics page, the homework page with instructions and tips on homeworks, and the policies page. You can navigate through the different pages via teh tabs at the top of each page. 

Canvas will be used as a way of communicating and distributing some materials, keeping track of the topics covered each week. The Canvas site for this course includes the schedule of lectures and a list of materials distributed in class. Canvas is also the means by which homework assignments are to be submitted as PDF uploads (more on homeworks below). There are three Canvas assignments for tests, which are  placeholders and will be used to convey information about the tests. The grade list on Canvas will be used to communicate the scores for the homework assignments and tests. Any other information calculated automatically by Canvas (e.g., average scores or grades) should be disregarded. 

Course Materials

The following materials are distributed in print at the beginning of the semester. There may be additions to these materials over the course of the semester. 

Illustrations and Data Packet: This packet contains materials that supplement the lectures. You should bring it with you to tests so that you can consult it. It may be supplemented by additional pages distributed later in the semester. You may annotate it with you own notes.

Note Sets and Reference Material: Several detailed note sets to supplement topics covered in class (e.g., detailed derivations), data on atomic processes, etc. 

Problem Set: Exercises that will be assigned during the semester. Some of the exercises will be turned in for credit and others will be used for practice. This set may be supplemented by other problems distributed later.

Assessed Work and Basis for Grades

The assessed work for this course consists of regularly assigned homework and two tests and a final exam. The final grade is based on a weighted combination of scores from the above (25% for each test, 25% for all homeworks combined). The final, letter grades will be assigned after considering the complete record of performance of each student and they will follow these rules:

A final, average score of... is guaranteed a grade of...

50% or higher D or better

60% or higher C or better

90% or higher A– or better

The dates of the tests and exams are:

Test 1: Thursday, October 1, 2026

Test 2: Thursday, November 12, 2026 

Final: To be scheduled by registrar during finals week, December 14–18, 2026

The final exam will be scheduled by the registrar's office during the week of final exams.

If the university is closed because bad weather (or any other reason) on the day of a scheduled test, the test will be given during the immediately following class period, unless other instructions are issued. If you get an announcement that university is closed also look for an e-mail message from your instructor about arrangements for the test.

The tests will be given in the regular classroom (unless announced otherwise) during regular class time. Each test and the final will largely examine material that was not examined in a previous test, as well as essential background and relevant material from earlier in the course. 

The printed Illustrations and Data Packet is allowed in the tests and exam. You are also allowed to add your own annotations and explanations on the pages of this packet. However, the Note Sets and Reference Material, packet, slide sets distributed in class, additional notes that you take during class, books or copies of pages from books, homework problems or earlier tests, and their solutions, or any other materials are not allowed. Calculators are allowed, but other electronic devices, such as phones, tablets, or laptops are not allowed (even if you intend to use them only as calculators). Calculators will very likely be needed for the tests and it is your responsibility to bring a calculator that you know how to use. 

As a rule, no makeup tests or exam will be given. Exceptions may be granted if a student missed the regularly scheduled test or exam because of a serious medical or family emergency or because of university business. It will be up to the instructor to approve the request for a makeup test. Students requesting a makeup test are expected to be cooperative and forthcoming with information and evidence to support their request (for example, a letter from the university or from a doctor). If a makeup test is approved, its content will likely be different from that of the regular test. The date and time of the makeup test will be set by the instructor after consultation with the student(s). Make-up tests will be given after the regular test, not before, and must be completed before the time of the next regularly scheduled test or the end of the semester in the case of the last test).

Homeworks will be assigned every week or every other week and their due date and time will be announced at that time. Typically, the due date will be one week after the assignment is issued. By the deadline, students are expected to upload their homework answers on Canvas. The answers for each homework should be submitted as a single, self-contained PDF file; they can be written by hand and then scanned or photographed (e.g., using Microsoft Lens or Adobe Scan), or they can be written on a tablet and exported to PDF, or they can be typed (or they can be produced by some other method that creates a PDF file). A PDF resolution of 200–300 dpi (dots per inch) is prefered because it results in readable text and files that are not too big to be unwieldy. At any rate, it is the responsibility of the students to make sure that the files they upload are readable and can be manipulated by Canvas without problems.

The official solutions will be distributed right after the deadline. This policy implies that there can be no extensions to the homework deadline (nor can homeworks be made up).

Detailed instructions and advice on how to solve homework problems and how to present the solutions are given in the homework page of this web site. The importance of homeworks should not be underestimated since they serve as essential practice for the type of problems that will appear on the test. In other words the homeworks are an extension of instruction; they will contain examples that are useful for understanding the material and they will also cover some topics that follow naturally from the lectures but are not covered explicitly or in great detail in the lectures themselves.

The Cardinal Rule

All students are responsible for knowing and following all the rules and regulations for this course as set forth in the syllabus. Not knowing the rules is not an excuse for not following them. In case of any ambiguity, the instructor is the final arbiter. Students are also responsible for knowing what is announced in class.