ASTR 222 - Galaxies and Cosmology

Spring 2018,
T/Th 10:00-11:15

Instructor: Professor Chris Mihos

Office: Sears 557
Office Hours: drop in or by appointment
Teaching Assistant: Joe Curro
Office: Sears 561
Office Hours: M 11:30-12:30, W 3:15-4:15

Course Website:

Textbooks: There are no required textbooks, but supplemental readings will come from:

Other Help Sources:

Grading Policies:

Homeworks can be discussed collaboratively, but each person must turn in their own solutions with unique writeup/analysis. Collaborative means talking with each other about approaches, techniques, etc. Collaborative does not mean sitting side-by-side working out the answers, or swapping final solutions to copy!

Homework will be accepted in hardcopy form only -- no electronic/email submissions. Assignments are due at 4:00pm on the due date unless otherwise noted.

Late HW policy: You get one free late homework
(up to one week late), no questions asked. After that, it's a penalty of 20% for every day late, unless you have an prearranged, excused reason.

Missed test policy: Don't miss tests. If you are ill or have some other critical reason for missing a test, you must let me know in advance of the test, and document the reason through Undergrad Studies.

Grade Weights:

Midterm #1
Midterm #2
Final Exam

Due Dates:

(subject to change...)

HW #1
Jan 30
HW #2
Feb 15
Midterm #1
Feb 27
HW #3
Mar 8
Mar 9, 3pm
HW #4
Apr 3
Apr 5
Midterm #2
Apr 12
HW #5
Apr 24
May 1
(any late HW must be in by May 4!)
Final Exam
take home, open notes
available May 1;
due 4pm on May 7

Grading Scale:


Learning Outcomes

After taking this course, students should be able to:
  • Describe the structure and kinematics of the Milky Way galaxy.
  • Understand techniques for determining distances both within our Galaxy and to other galaxies.
  • Characterize the properties of galaxies of different morphological type.
  • Describe how galaxies cluster in the universe.
  • Understand the kinematic scaling relationships for galaxies of different types.
  • Explain how galaxy interactions drive evolution in galaxies and clusters.
  • Describe the various cosmological parameters and their effect on the expansion history of the Universe.
  • Derive quantitative relationships for the expansion history of the universe.
  • Describe qualitatively the evolution of the hot big bang model.
  • Describe the growth of structure and the evolution of galaxies as a function of cosmic time.
  • Describe current galaxy formation models.
  • Retrieve and use online datasets to study our Galaxy and other galaxies.
  • Write quantitative computational tools to analyse astronomical datasets.

Schedule and Content
(all subject to change)

Date Topic Reading
Jan 16 Introduction to the Milky Way, Star Counts
K: 16.1
CO: 24.1
Jan 18 Size of the Milky Way
Distances to Stars
K: 2.6, 3.5, 10.2, 13.1, 13.4, 14.2
CO: 3.1, 12.1, 13.3, 14.1
Jan 23
Variable Stars: Cepheids and RR Lyrae stars
Metallicity and Stellar Populations

Jan 25 Structure of the Milky Way: Disk, Bulge
Face-on Milky Way schematic
The Galactic Halo
K: 16.1
CO: 24.2
Jan 30
The Interstellar Medium,
Multiwavelength Milky Way (with helpful finder chart!)
Solar Motion

K:14.4, 16.4
CO: 12.1, 24.3
Feb 1
The Velocities of Stars

K: 16.2, 16.3
CO: 24.3
Feb 6
Discussion of HW #1 and HW #2

Feb 8
Galactic Rotation and Dark Matter

K: 16.2, 16.3, 16.6
CO: 24.3, 24.4
Feb 13
The Galactic Center, The Central Object K: 16.6
CO: 24.4
Feb 15 Environment: Satellite Galaxies and the Local Group
Intro to Galaxies: The Great Debate
Galaxies: Morphology of Galaxies, General Properties
K: 17.1-17.3
CO: 25.1-25.3
Feb 20
Galaxies: Stellar Populations and Stellar Mass-to-Light Ratios

Feb 22
Discussion of HW #2, Stellar Pop mixing, Filters, Colors, spectra.

Feb 27
Midterm Exam #1 (covering material up to and including Feb 20)

Mar 1
Disk Galaxies: Kinematic Properties
Discussion of HW #3; statistics and error propagation
K: 17.1.2
CO: 25.2
Error propagation
Mar 6
Disk Galaxies: Photometric Properties
K: 17.1.2
CO: 25.2
Mar 8
Disk Galaxies: Spiral Structure
Elliptical Galaxies: Structure and Stellar Populations
K: 17.1
CO: 25.4
Mar 13
Spring Break - no class

Mar 15 Spring Break - no class

Mar 20
Elliptical Galaxies: Kinematics
Peculiar Galaxies: Starbursts
Extragalactic Distances and Hubble's Law
CO 25.4, 27.2
K 19.1-19.6

Mar 22
Discussion of HW#3 and HW#4

Mar 27 Peculiar Galaxies: Interactions
Active Galaxies and Quasars
CO: 26.1, 28.1-28.2
K 19.2-19.6
Mar 29 Active Galaxies and Quasars
Galaxy Clusters and Large Scale Structure
CO 28.1-28.2, 27.3
K 18.1-19.2
Apr 3
The Expanding Universe CO 27.2, 29.1
K 18.3, 20.2
Apr 5
The Age of the Universe: first attempt
The Microwave Background
CO 29.1, 29.2
K 20.3, 21.1
Apr 10
Observational Cosmology with Supernovae
The Cosmological Constant
CO 29.1, 29.2
K 20.2-20.4
Apr 12
Midterm Exam #2
(covering material through Microwave Background)

Apr 17
The Growth of Primordial Fluctuations
Hot and Cold Dark Matter,
Structure Formation
CO 30.2
K 21.4
Apr 19
Cosmological Models: Observational Constraints
Ages and Lookback Times
The Early Universe: Inflation, BBN, and Recombination
CO 30.1, 30.2
Apr 24
The Early Universe: Inflation, BBN, and Recombination
Observing the High Redshift Universe

Apr 26
Galaxy Formation (Theory)
Galaxy Formation (Observational)
K 21.4.3
CO 26.2
May 1-7
Final Exam: take home, open notes
Available May 1; due back no later than 4pm on May 7

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