Physics/Astro 443 -- Spring 2021

Galaxies and the Milky Way

Professor: Alyson Brooks

hubble ultra deep fieldgalaxy imagecoma
Hubble Ultra Deep Field; Hubble Heritage image M66; Coma cluster

1. Overview and Course Description

Galaxies are an important nexus in the cosmic hierarchy: they serve as lighthouses marking out the vast cosmic structures that can span many millions of parsecs, but are fascinating in themselves as laboratories for the "small scale" processes of stellar birth and evolution. We now have images of billions of galaxies, and can observe them from a time less than a billion years after the Big Bang until the present day. We can study not only the appearance or "morphology" of galaxies, but also in some cases measure properties of their stellar populations, their quota of heavy elements, their gas content, and the internal motions (or kinematics) of their stars and gas. Although galaxies exhibit amazing diversity, they also conform to certain surprisingly tight correlations. From kinematic measurements, we can infer that galaxies contain a major unseen component that influences the motions of their stars and gas: the mysterious "dark matter". Moreover, the stars and gas that we can measure within galaxies falls far short of what we would expect for the cosmic baryon budget. The study of modern galaxy formation focuses on trying to understand the observed demographics and correlations of galaxy properties and how these evolve over cosmic time, in the context of the "hierarchical structure formation" picture provided by the Cold Dark Matter galaxy formation theory.

In this course, we will warm up with a brief review of stars and radiative processes and basic cosmology. We will start our study of galaxies with our home Galaxy, the Milky Way, our sister galaxy M31 (Andromeda), and our smaller companions the Local Group dwarfs. Even this relatively small population of galaxies in our own "backyard" poses a number of unsolved puzzles. We will then cover the properties of spiral, lenticular, and elliptical galaxies in the 'nearby' Universe, and discuss the larger structures that form galaxy habitats: groups and clusters. One fascinating open question is whether galaxy properties are mainly shaped by "internal" processes or by their environment. We will discuss the evidence that many or even most galaxies harbor supermassive black holes in their nuclei. We will review basic cosmology and paint a picture of galaxy formation over time. We will wind up the course with a discussion of how we can find and observe extremely distant (high redshift) galaxies, and of how galaxies were different in the past.

2. Instructor and Venue

Prof. Alyson Brooks
email: abrooks [at]
office: 306 Serin
office hours TBD (and by appointment)

This course will be held remote synchronous via zoom.
All course materials will be found on our Canvas site.

4. Textbook

The main text for the course is An Introduction to Galaxy Formation and Evolution by Cimatti, Fraternali, and Nipoti.

Several other textbooks that may be useful for supplemental reading are: 

Extragalactic Astronomy and Cosmology, Second Edition, by Peter Schneider
Galaxy Formation and Evolution by Mo, van den Bosch & White: a recent and comprehensive graduate level textbook.
Introduction to Cosmology by Ryden: very useful and clear text if you need to brush up on your cosmology
An Introduction to Modern Astrophysics by Caroll & Ostlie: useful basic reference

3. Class Format and Grading

The course will be run as a lecture/discussion, and in order for this to work well, it is imperative that students complete the assigned reading before class. Grades will be based on approximately 5 homework assignments (30%), 5 quizzes (30%), and a final paper (15%) including peer review (10%) and presentation (15%).

Problem sets will be posted to Canvas.

In lieu of a final exam, a final paper will be written (and due at the end of the formal exam time).

General concept
Week 1
Week 2
Stellar Populations;
Week 3
Radiative Processes;
PS #1 due
Week 4
morphology, structure;
surveys & populations;
Quiz 1
Week 5
large scale structure;
expanding Universe
PS #2 due
Week 6
structure formation
Quiz 2
Week 7
galaxy formation
project proposals due
Week 8
Local Group
hierarchical formation
PS #3 due
Week 9
chemical evolution;
the Local Group as a Laboratory
Quiz 3
begin docking points from late project proposals
Week 10
Disk Galaxies
Keeton 7.1/7.2/7.3
PS#4 due
Week 11
spiral arms; galaxy centers & bars;
scaling relations
Keeton 7.4
presentations begin;
paper drafts due
Week 12
Elliptical Galaxies
scaling relations
Keeton 8.2/8.3
Quiz 4
Week 13
clusters of galaxies; AGN
New paper drafts due ;
PS #5 due
Week 14
High z
finding distant galaxies;
student presentations
Peer reviews due; Quiz 5
Week 15
student presentations
Final Exam Period
student presentations
final papers due

Astro Resources

Here are some web resources you may find illuminating or indispensable:


Rutgers Resources

Here are some web resources you may find illuminating or indispensable (all of these services are being provided remotely during Spring 2021):

Disability Services
(848) 445-6800 / Lucy Stone Hall, Suite A145, Livingston Campus, 54 Joyce Kilmer Avenue, Piscataway, NJ 08854
Rutgers University welcomes students with disabilities into all of the University's educational programs. In order to receive consideration for reasonable accommodations, a student with a disability must contact the appropriate disability services office at the campus where you are officially enrolled, participate in an intake interview, and provide documentation. If the documentation supports your request for reasonable accommodations, your campus’s disability services office will provide you with a Letter of Accommodations. Share this letter with your instructors and discuss the accommodations with them as early in your courses as possible. To begin this process, please complete the Registration form on the ODS web site.

Counseling, ADAP & Psychiatric Services (CAPS)
(848) 932-7884 / 17 Senior Street, New Brunswick, NJ 08901
CAPS is a University mental health support service that includes counseling, alcohol and other drug assistance, and psychiatric services staffed by a team of professional within Rutgers Health services to support students’ efforts to succeed at Rutgers University. CAPS offers a variety of services that include: individual therapy, group therapy and workshops, crisis intervention, referral to specialists in the community and consultation and collaboration with campus partners.

Violence Prevention & Victim Assistance (VPVA)
(848) 932-1181 / 3 Bartlett Street, New Brunswick, NJ 08901
The Office for Violence Prevention and Victim Assistance provides confidential crisis intervention, counseling and advocacy for victims of sexual and relationship violence and stalking to students, staff and faculty. To reach staff during office hours when the university is open or to reach an advocate after hours, call 848-932-1181.

A list of resources and policies.