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Principles of Astrophysics

Undergraduate level course PHYS 342​ (Spring 2023)
Monday & Wednesday 2:00 - 3:20 pm
Instructor Prof. McQuinn

Astrophysics is the application of physical principles to astronomical systems. In Physics 341 and 342 you will learn how to use gravity, electromagnetism, and atomic, nuclear, and gas physics to understand planets, stars, galaxies, dark matter, and the Universe as a whole. In Physics 342 we will focus on the question: How did we get here?

Our story will include the nucleosynthesis of hydrogen and helium in the first few minutes after the Big Bang 13.7 billion years ago, the formation of stars from this primordial gas, and the forging of heavier elements, such as carbon, nitrogen, and oxygen, among all others within these stars' nuclear furnaces. Around at least one star in the Universe some of these heavy elements coagulated to form a rocky planet with a tenuous atmosphere. On this planet Earth, the energy from the star and the gas in the atmosphere were just right to allow the emergence of life. The energy that sustains us originated deep in the Sun, thanks to E=mc2 . The atoms that comprise our bodies were made inside dying stars. Literally, we are star dust. The goal of Physics 342 is to understand the physics of this remarkable story.

Some astrophysical systems are described by equations that are fairly easy to solve, and we will certainly study them. However, many interesting systems cannot be solved exactly. Nevertheless, we can often use physical insight and approximate calculations to understand the salient features of a system without sweating the details. One goal of the course is to develop that skill. As you will see, it will take us very far (through the whole Universe, in fact!). Another goal is to learn about recent advances in astrophysics, a very dynamic field of research.
Prerequisites for this class are two semesters of physics and two semesters of calculus. Previous study of modern physics is a must. I will briefly review physical principles as we need them, but assume that you have seen them before. I will also assume familiarity with vector calculus. Some of the assignments may involve a bit of computation that can be done with programs like Excel, Google Spreadsheets, Maple, Matlab, or Mathematica. Note that Physics 341 is not a prerequisite for Physics 342; the two courses are designed to be complementary, but independent.
NASA-Sun.jpg

Our Sun; Image by NASA

Lectures will be based on the course textbook, Principles of Astrophysics: Using Gravity and Stellar Physics to Explore the Cosmos, by Prof. Chuck Keeton. (It was written specifically for this course.) Optional, supplementary information can be found in An Introduction to Modern Astrophysics (2nd edition) by Bradley W. Carroll and Dale A. Ostlie (affectionately known as the Big Orange Book).

Instructor Contact Information

Prof. Kristen B. W. McQuinn
Email: kristen.mcquinn@rutgers.edu (you can generally expect an email reply within 24 hours during the week and 48 hours during a weekend; if you don't receive one, send your email again)

Office hours: Wednesdays time TBD.

Learning Goals

Here are specific learning foals for this course:

  • Understand physics principles and their application to astronomical systems

    • Specifically, understand how to use electromagnetism and atomic, nuclear, and gas physics to understand planets, stars, and galaxies

  • Become skilled at estimation techniques, including using dimensional analysis, scaling relations, and Taylor series expansions

  • Learn about exciting developments in astrophysics (including results from NASA's new flagship mission: JWST!)
     

The top 25% of our Physics majors demonstrate mastery of basic Physics and the ability to solve essential problems appropriate for beginning graduate study in Physics. All Physics majors demonstrate knowledge of fundamental Physics principles and are able to quantitatively analyze a broad spectrum of problems presented in a range of undergraduate Physics courses.

Students with disabilities requesting accommodations must follow the procedures outlined at https://ods.rutgers.edu/students/getting-registered. Full disability policies and procedures are at https://ods.rutgers.edu/

Assessment

We will have weekly problem sets due on Thursdays by 5pm and submitted to Canvas. To submit the HW, please scan (or take a picture of) your completed problem sets with your phone and upload a pdf to canvas.  In working on the problem sets, you are encouraged to work in groups, though your submitted write-up should be your own. You must list your collaborators on the write-up. You are allowed to consult outside reference material (which must be cited), but you may not examine problem sets or solutions from previous years of Physics 341/342 or other similar courses online, nor are you allowed to post problem set or exam questions online. No late problem sets will be accepted! No exceptions!

Always show your work. You will not receive full credit if you do not show your work. I will never look for a specific answer. Rather, I am always looking for the reasoning behind the answer.

 

There will be one midterm exam and a final exam. Details about these will be provided as the semester progresses.

 

The course grade will be calculated from the problem sets (60%), in-class iClicker participation (10%), the midterm exam (15%), and the final exam (15%). A course grade of 90% or higher will guarantee you an A. The two lowest problem set grades will be dropped in calculating the course grade. While that means you could skip two problem sets and still get a perfect score, experience has shown it is typically much better for your grade to turn in all of them and have the two lowest scores dropped.

Academic Integrity

Students are expected to maintain the highest level of academic integrity. You should be familiar with the university policy on academic integrity. Violations will be reported and enforced according to this policy.  As per the policy, all suspected violations will be reported to the Office of Student Conduct. Academic dishonesty includes (but is not limited to):

  • Cheating

  • Plagiarism

  • Aiding others in committing a violation or allowing others to use your work

  • Failure to cite sources correctly

  • Fabrication

  • Using another person’s ideas or words without attribution–re-using a previous assignment Unauthorized collaboration

  • Sabotaging another student’s work

Use of external website resources (such as Chegg.com or others) to obtain solutions to homework assignments or exams is cheating and a violation of the University Academic Integrity policy. Cheating in the course may result in grade penalties, disciplinary sanctions or educational sanctions. Posting homework assignments or exams to external sites without the instructor's permission may be a violation of copyright and may constitute the facilitation of dishonesty, which may result in the same penalties as cheating. 

 

The Rutgers honor pledge will be included on all major assignments for you to sign: On my honor, I have neither received nor given any unauthorized assistance on this examination/assignment.

 

Almost all original work is the intellectual property of its authors. In this course, this includes syllabi, lecture slides, recorded lectures, homework problems, exams, and other materials, in either printed or electronic form. You may not copy this work, post it online, or disseminate it in any way without the explicit permission of the instructor. Respect for the author's efforts and for the author’s intellectual property rights is an important value that members of the university community are expected to take seriously.

Resources
Schedule: Topics and Assignments

This syllabus may be modified and the schedule updated as the semester progresses.

Note: Under the "Text" column, "Ch" mark the Chapters in Keeton. "CO" refers to Carroll & Ostlie, on reserve at the Library of Science and Medicine

NGC 4449; Image by McQuinn et al. (2019)

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