Astrophysics deals with some of the most majestic themes known to science. Among these are the evolution of the universe from the Big Bang to the present day; the origin and evolution of planets, stars, galaxies, and the elements themselves; the unity of basic physical law; and the connection between the subatomic properties of nature and the observed macroscopic universe.
Assistant Chair for Academic Affairs: Richard Kron
Academic Affairs Administrator: Julia Brazas
Student Affairs Administrator: Laticia Rebeles
Several courses offered by the Department of Astronomy and Astrophysics satisfy the Core requirement in the Physical Sciences. Sequence descriptions may be found on the Physical Sciences page of the College Catalog. As of Autumn Quarter 2015, PHSC 11900, 11902 and 12000 were no longer offered. Students who have taken 11900 or 11902 but have not taken 12000 may complete their Core requirement by taking PHSC 12600, PHSC 12710 or PHSC 12720. Students who have taken 12000 may complete their Core requirement by taking PHSC 12600, PHSC 12610 or PHSC 12700.
PHSC 12600. Matter, Energy, Space, and Time
A comprehensive survey of how the physical world works, and how matter, energy, space, and time evolved from the beginning to the present. A brief survey of the historical development of mathematics, physics, and astronomy leads to a conceptual survey of the modern theory of the physical universe: space and time in relativity; the quantum theory of matter and energy; and the evolution of cosmic structure and composition. Systems such as black holes are used to illustrate the most extreme behaviors of nature, and systems such as stars are used to illustrate the explanatory power of physical reasoning. The major theme is understanding all of nature, from the prosaic to the exotic, using a powerful quantitative theory grounded in precise experiments.
PHSC 12610. Black Holes
The Universe is a laboratory that reveals the behavior of matter and radiation under intense pressure, temperature, and density, far more extreme than can be replicated on Earth. Depending on its mass, a star ends its life as a spinning white dwarf, neutron star, or black hole. The strength of gravity near these compact dead stars is so high that we can observe consequences of the bending of space-time. This course will provide the physical framework necessary to understand the origin and properties of some of the most powerful and exotic phenomena known, such as supernovae, gamma-ray bursts, and quasars.
PHSC 12620. The Big Bang
The Big Bang model is a powerful framework for the interpretation of a wide range of observations and for making detailed and precise predictions for new experiments. The key motivating observations include the expansion of the Universe and how it has changed with time; the existence of radiation indicating a hot and dense early phase; the abundance of the light elements; and how matter is organized over a wide range of physical scales. The model naturally incorporates dark matter and dark energy, components that govern the growth of structure over time under the action of gravity. The course will explore the consequences of the model as it is applied to the earliest moments after the Big Bang, as well as to the fate of the Universe in the distant future.
PHSC 12700. Stars
Elements such as carbon and oxygen are created at high temperatures and pressures in the deep interiors of stars, conditions that naturally arise in stars like the Sun. This course will outline the physical principles at work: how the theory of stellar interiors accounts for how stars shine, why they live for such long times, and how the heavy elements in their cores are dispersed to form a new generation of stars. Gravity assembles stars out of more diffuse material, a process that includes the formation of planetary systems. The course shows how, taken together, these physical processes naturally lead to the ingredients necessary for the emergence of life, namely elements like carbon, nitrogen, and oxygen, and planets in stable orbits around long-lived stars.
PHSC 12710. Galaxies
Galaxies have been called "island universes," places where stars are concentrated, where they are born, and where they die. Galaxies are dynamic systems in the sense that they change with time and in the sense that gravity shapes the orbit of each star within its galaxy. The Sun is one star among the 100 billion in the Milky Way, each moving on an orbit that reflects the distribution of all the other stars. This course will trace the modern picture for the formation of galaxies and the stars in them. It will also review aggregates of galaxies, how galaxies move on orbits around each other at this higher level of the hierarchy of structure, and how we arrive at the conclusion that most of the matter in the Universe is in an exotic form (dark matter).
PHSC 12720. Exoplanets
The past two decades have witnessed the discovery of planets in orbit around other stars and the characterization of extra-Solar (exo-) planetary systems. We are now able to place our Solar System into the context of other worlds: A challenging next step is to find planets as small as the Earth in orbit around stars like the Sun. The architecture of planetary systems reflects the formation of the parent star and its protoplanetary disk, and how these have changed with time. This course will review the techniques for discovery of planets around other stars, what we have learned so far about exoplanetary systems, and the driving questions for the future, including the quest for habitable environments elsewhere.
PHSC 12800. European Astronomy & Astrophysics
Modern Astronomy was born in Europe in the sixteenth and seventeenth centuries, led by Nicolaus Copernicus of Poland, who simplified the description of the solar system by moving the Sun to the center of the Universe. The Italian, Galileo Galilei, first pointed a telescope at the sky in 1609 and discovered the moons of Jupiter, sunspots, the stellar composition of the Milky Way, and craters of the Moon. Tycho Brahe of Denmark studied planetary motions in great detail, allowing Johannes Kepler of Germany to define the principles of the orbits of the planets by 1615. Isaac Newton of England discovered the laws of gravity and of motion, and built the reflecting telescope later in the seventeenth century. By 1774, French astronomer Charles Messier began the explosion of our current knowledge of the Universe when he catalogued what are now known to be other galaxies. Building upon this history, this course also explores recent developments in European astronomical and astrophysical technology that allows a modern exploration of the deepest regions of the Universe using a wide range of telescopes.
*This course is offered only in the Spring Quarter Paris program.
ASTR 18000. The Search for Extraterrestrial Life
Offered in alternate years
The origin of life is one of the biggest questions of modern science. While substantial progress has been made in understanding how life arose on our planet, such research represents just a single case study in how life originates and evolves. This course covers the search for life beyond
Earth from the planets and moons of the Solar System to planets orbiting other stars and intelligent life that may have left its mark on macroscopic scales. The discovery of life beyond Earth would be transformative for our understanding of humanity's place in the universe.
A range of ongoing and planned experiments have the potential to detect or put strong constraints on the existence of life during the next few decades. This class will mix traditional lectures with flipped classroom problem solving sessions.
ASTR 18100. The Milky Way
Within a largely empty universe, we live in a vast stellar island that we call the Milky Way. As we survey the stellar and interstellar components of the Milky Way, the distribution and motions of stars and interstellar gas, and how these dynamic, ever-changing components interact with each other during their life cycles inside the Milky Way, we will follow the path of ancient astronomers, wonder at their mistakes and prejudices, and form our own understanding.
ASTR 18200. The Origin and Evolution of the Universe
This course discusses how the laws of nature allow us to understand the origin, evolution, and large-scale structure of the universe. After a review of the history of cosmology, we see how discoveries in the twentieth century (i.e., the expansion of the universe and the cosmic background radiation) form the basis of the hot Big Bang model. Within the context of the Big Bang, we learn how our universe evolved from the primeval fireball.
ASTR 18300. Searching Between the Stars
With the advent of modern observational techniques such as radio and satellite astronomy, it has become possible to study free atoms, molecules, and dust in the vast space between the stars. The observation of interstellar matter provides information on the physical and chemical conditions of space and on the formation and evolution of stars.
ASTR 18400. Origins: From the Big Bang to Human Consciousness
Offered in alternate years
In this course we will look at the approaches to, data for, and theories of the big transitions in the evolution of the physical universe and the living world.
ASTR 18500. The Lives and Deaths of Stars
In this course we study the observed properties of stars and the physics that enables us to understand them. Star formation, stellar evolution, and the deaths of stars are discussed.
ASTR 20000. Tutorial in Astronomy and Astrophysics
Students in this tutorial read topics in astronomy and astrophysics under the supervision of a faculty member. Students meet with the instructor in groups of one to three for approximately two hours per week to discuss readings on mutually agreed-upon topics.
ASTR 23000. Looking for Ourselves Elsewhere
Science and religion are two ways, among many others, that people can seek to know about reality: how do we construct ordered pictures of the whole—cosmos or civilization—and how do we relate to them in terms of action? How do we know what we do not know, and what does that kind of “knowledge” mean for the orientation and direction of human existence? How would cultural biases be affected by knowing that there are others “out there” in the universe, should we discover them? From various perspectives, this course addresses these questions of the origins, structures, and ends of reality as we look for ourselves—seek understanding of the human condition—in the cosmos but also in complex religious and cultural traditions. Whereas in our popular culture, science is often identified with the realm of knowledge and religion is simply “belief” or “practice,” the course also seeks to trace the rational limits of science and the rational force of religion with respect to the ethical problem of the right and good conduct of human life.
ASTR 23900. Physics of Galaxies
This course will provide a comprehensive introduction to the formation and evolution of galaxies, review key components such as stars, gas, dust, and dark matter, and examine the physical processes involved in their structure and evolution. The discussion will start with the Milky Way as an example and transition to the general properties of nearby galaxies and beyond. Topics will include the stellar content of galaxies and the dynamics of stars within galaxies, the physical state of the interstellar medium, central supermassive black holes, clusters of galaxies, gravitational lensing, and processes that shape the relative distributions of dark matter and baryonic matter.
ASTR 24100. The Physics of Stars and Stellar Systems
Building upon a student's previous knowledge of physics, this course introduces the astrophysics of stars and stellar systems with an emphasis on the physical nature of stars. Topics include the tools of astronomy, both observational and theoretical Hertzsprung-Russell diagrams, structure and evolution of stars, binary stars, star clusters, and end states of stars such as white dwarfs, neutron stars, and black holes.
ASTR 24200. The Physical Universe
Physical laws are applied in the study of the structures and evolution of galaxies, quasars, clusters of galaxies, and the universe at large.
ASTR 28200. Current Topics in Astrophysics
In Winter Quarter 2018 Current Topics in Astrophysics will focus on Catching Long-Wavelength Photons.
Many important events in the history of our universe are best observed at wavelengths between the microwave and the far-infrared. These include the cosmic microwave background (CMB), the early galaxies which played host to the first stars during the epoch of reionization, and the astrophysical processes which drive nearby star forming regions. This class will introduce these science topics and then explore in detail the tools and techniques required to measure this radiation. Topics will include: antennas, horns, and direct absorbers; receiver sensitivity and fundamental noise sources; coherent detectors, bolometers, and pair-breaking superconducting devices; microwave theory and interferometry; telescope fundamentals; and a survey of current and near-future instruments. This course should provide a comprehensive background for students interested in instrumentation for the CMB, submm, and far-IR astronomy. Grading will include problem sets and a final project in which students design their own detailed instrument proposal. There are no lab sections, though some class sessions will involve hands-on demonstrations in a research lab on campus.
ASTR 29700. Participation In Research: Astronomy and Astrophysics
Students are assigned to work in the research group of a member of the faculty. Participation in research may take the form of independent work on a small project or assistance to an advanced graduate student or faculty member in his or her research.
ASTR 30100. Stars
Introduction to stars (physical and observational), hydrodynamics of self-gravitating fluids, statistical mechanics and equations of state, energy transport, astrophysical nuclear reactions, stellar models, advanced topics.
ASTR 30300. Interstellar Matter
This course will cover a range of physical processes that govern the thermal and dynamical states of interstellar gas in molecular, atomic, and ionized phases. It will explore different spectral features and line diagnostics for gas density, ionization state, temperature, chemical compositions, and dust content.
ASTR 30400. Galaxies
The observed universe, the universe at high redshift, early universe microwave background radiation, relativistic homogeneous isotropic cosmologies, evolution of structure in the universe, primordial nucleosynthesis.
ASTR 30600. Radiation Measurements in Astrophysics
Radiation as a random process, optical coherence, and signal analysis in spatial and temporal domains, along with the detection and measurement of radiation with astronomical instruments.
ASTR 31000. Cosmology I
Large scale structure of the universe, expansion, composition, epochs, measurements.
ASTR 31100. High Energy Astrophysics
This course covers a wide range of phenomena associated with the astrophysics of high energy photons, cosmic rays and neutrinos, including the processes of ionization, bremsstrahlung, synchrotron, pion production, Compton and inverse Compton scattering, as well as cosmic ray acceleration. Specific sources of high energy emission will also be discussed, including active galaxies, pulsars, gamma-ray bursts and supernova remnants.
ASTR 31300. Extragalactic Astronomy
When, where, and how stars formed in galaxies is central to understanding many other aspects of large stellar systems: baryons streaming into dark-matter haloes, large-scale outflows, patterns in chemical abundances, and how all these processes have changed with time. This class will look at what is known empirically about star formation in nearby galaxies across a wide range of conditions, identifying those that are most significant for building up the mass in stars and most significant energetically for the local interstellar medium. The range of conditions includes strong dynamical interactions on large scales, and high-density regions and regions exposed to intense radiation on small scales. Our approach will study prototype galaxies from relevant classes (e.g. starburst, ultra-luminous infrared emitters, ultraviolet-luminous, etc.), exploring what is known about the recent history of star formation in these systems from multi-wavelength data.
ASTR 31500. Dynamics I (Fluids)
Principles of hydrodynamics and hydromagnetics. Equilibrium and stability of fluid systems in astrophysics. Waves. Shocks. Turbulence.
ASTR 31600. Dynamics of Particles
Dynamics of collisionless plasmas and stellar systems. Stochastic processes and kinetic equations. Dynamics of galaxies and star clusters. Astrophysical plasmas.
ASTR 32000. Relativistic Astrophysics
Special and General relativity and the experimental tests, with applications to astrophysical problems such as super-massive stars, black holes, relativistic star clusters, and gravitational radiation.
ASTR 32100. Cosmology II
Study of physical cosmology with emphasis on the standard big-bang model and its observational and experimental tests.
ASTR 33000. Computational Physics and Astrophysics
Basic computational methods useful for astrophysics, supplemented by specific examples drawn primarily from astrophysics. Starting with basics (e.g., precision, errors and error analysis) and basic computational methods (differentiation, integration/quadrature, Monte Carlo, numerical linear algebra), and then discussing solution of problems posed in terms of ordinary and partial differential equations.
ASTR 34000. Statistical Methods in Astronomy and Astrophysics
An exploration of the variety of statistical methods used in modern astrophysics. We discuss the frequentist (hypothesis tests, confidence intervals) and Bayesian (explicit priors, model-choosing, parameter estimation) approaches. Other topics include: Markov Chain Monte Carlo and other computational statistics; multi-dimensional likelihood space; Fischer information matrices; time series analysis. Assignments draw from examples in the astronomical literature.
ASTR 35800. Extrasolar Planets
Extrasolar planets, a.k.a. exoplanets, are planets orbiting other stars. First definitively detected in the mid 1990s, the planet count has rapidly expanded and their physical characterization has sharpened with improved observational techniques. Theoretical studies of planetary formation and evolution are now attempting to understand this statistical sample. The field also aspires to address questions about life in the universe. This course emphasizes hands-on activities, like working with real astronomical data to find and characterize exoplanets. Topics are the radial velocity, transit, and other discovery and characterization techniques; statistical distributions of known planets; comparisons among planet structure and planetary system types; formation in a protoplanetary disk and subsequent dynamical evolution; the goal of finding life on an exoplanet; colonization of exoplanets and the Fermi paradox.
ASTR 36100. Interstellar Medium
Advanced topics in interstellar matter, depending on current forefront research and interest of the instructor.
ASTR 36101. Quantum Mechanics of the Interstellar Medium
The physics of interstellar gases can be determined from the ionization and excitation state of interstellar atoms and molecules. The conditions so determined can be used to determine, in turn, the more general physics of the Universe, the large scale clustering of gas, the properties of star-forming clouds and the causes of the state of the Galactic interstellar medium and of the intercluster medium, beyond the Galaxy.
The course examines the energy-level diagrams of the elements of the periodic table and the molecules they form, to explore how the abundances of the first elements from the Big Bang are determined (D, He, Li); how the clustering of dark matter in the cosmic web can be read in the abundant hydrogen clouds in space; how the temperature of the cosmic background and its evolution in redshift can be determined (CN, diffuse interstellar bands, CO); how the ionization state of the intergalactic medium can be determined; how molecular hydrogen reveals the radiation density and the particle density in diffuse molecular clouds; how the cosmic evolution of the elements can be determined, within galaxies and in the intergalactic medium; among other such topics.
ASTR 37100. Pre-Candidacy Research
Supervised research of students normally in their first two years of graduate study.
ASTR 37200. Readings in Astronomy and Astrophysics
The course instructor guides readings and discussions on exploratory research topics or more general topics for students-at-large.
ASTR 38000. History of the Telescope
The history of the idea of telescopes, and of telescopes as working devices, is covered. Following a short discussion of the ideas of "seeing at a distance" in the pre-telescopic world, Galileo's astronomical discoveries are noted. The evolution of the telescope through the 17th, 18th, 19th and 20th centuries are then described. The key developments in telescope systems in each century are highlighted. These include optics, platforms and clocks, structures, rockets, computers, instruments, detectors and observatory sites. The roles of amateur astronomers, wealthy patrons, wealthy entrepreneurs and governments in bringing about these developments are emphasized, and the impact on society of the discoveries made with telescopes is outlined. Serendipitous discovery, personal stories of the main actors on the stage and the feedback between the development of modern civilization and the tools of astronomy are features of the story.
ASTR 38800. Galileo's Astronomy and Conflicts with the Church
This course is devoted to Galileo's work in astronomy, above all the Dialogue on the Two Great Systems of the World, and his conflicts with the Church concerning the interpretation of Scripture and the attempt to prove the Copernican theory.
Specialized and Advanced Graduate Courses
Courses numbered 40000 - 48000 are lecture or seminar courses taught from time to time in specialized or advanced topics in fields in which members of the department are working. Admission to any of these is by permission of the instructor. Typical courses include:
ASTR 40100. Practical Data Analysis
This course will touch on basic issues related to analyzing and interpreting astronomical data. An emphasis will be placed on understanding the limitations and biases in different types of observations and measurements, and on finding ways of addressing and quantifying them. The course will be project driven so that the students will gain hands-on experience working with different types of data. The projects will cover a range of topics that involve imaging and spectral analysis, and explorations of public data archives.
ASTR 40400. QSOs in the SDSS
One of the main classes of spectroscopic targets of the Sloan Digital Sky Survey has been quasars. The SDSS database contains high-quality spectra for over 100,000 quasars, a sample that can be evaluated statistically because the sample selection is known to high precision. This course will explore the range of research enabled by these data, both spectroscopic and photometric.
ASTR 40600. Gravitational Lensing
Theory of bending of light by gravitational potentials followed by astrophysical and cosmological applications including: microlensing, planetary searches, strong lensing, and weak lensing. In different years, a subsample of these topics may be taught, based on interests of the instructor.
ASTR 40800. The Perturbed Universe
This seminar course will cover inflation as the source of structure in the universe and its observational signatures. Topics will include relativistic perturbation theory, canonical and general single field inflationary models, primordial non-Gaussianity, and gravitational waves.
ASTR 40900. Topics in Observational Cosmology
Specialized problems in the field, depending on current forefront areas and interest of the instructor. The topic for Spring Quarter 2018 will be Superconducting Detectors.
ASTR 41100. Science of the Dark Energy
Is the accelerated expansion of the Universe due to dark energy or does it require a modification of gravity? This informal seminar course will focus on the use of the Dark Energy Survey (DES), and by extension other surveys, to probe the origin of cosmic acceleration. The course will cover the techniques for probing dark energy in detail, with particular emphasis on weak and strong lensing, clusters, large-scale structure, cross-correlations with the CMB, and supernovae, and explore how DES will realize these techniques. We will familiarize ourselves with the main hardware and software components of the project that underlie the data and science it produces. Students will be given access to proprietary DES data and learn basic techniques for querying the database and looking at the data; and will formulate projects involving analysis of the data, depending on their interests and level of expertise, and report on their findings later in the quarter. By the end of the course, those interested in participating in the DES should have the basic tools to jump into the project (or other projects) and take part in science analysis, and those already involved will hopefully have their skills and knowledge enhanced. The course will start with lectures reviewing cosmic acceleration and the techniques for probing dark energy, continue with more specialized talks and discussions on various aspects of the Dark Energy Survey project and science, including discussion of early DES science papers, and finish with student presentations on DES data exploration and analysis.
ASTR 41300. Topics in Stellar Astronomy
Specialized problems in the field, depending on current forefront areas and interest of the instructor.
ASTR 41600. Intergalactic Medium
Specialized topics based on forefront topics in the field and on interests of the instructor.
ASTR 41800. Intergalactic Medium
Introduction to intergalactic medium studies. The course will begin with a historical overview of absorption-line studies and proceed with in-depth discussion of on-going research topics. These include the re-ionization epoch, chemical enrichment of the universe, and association between luminous matter traced by galaxies and gaseous clouds probed by absorption-line observations.
ASTR 43200. High Energy Cosmic Particles
This graduate level course will focus on high-energy particle astrophysics from basic facts to recent discoveries in the study of cosmic rays, gamma-rays, and neutrinos. The course will introduce the main concepts of proposed mechanisms for generating these particles, the past and current detections techniques and observatories, and recent observations. Some particle physics and cosmology will be covered including models of dark matter particles and the effect of cosmic backgrounds on high-energy cosmic particles.
ASTR 44900. Cosmic Acceleration
The first half of the course will be lectures with the goal of establishing a common denominator, and the second half will be research. The course requires a final project to be presented in class. Prerequisites are graduate-level cosmology and general relativity.
ASTR 45000. Extreme Optics
Frontiers in optics will be a review of the state of the art in optics as it applies to astronomy. Topics to be covered will include single dish optics: adaptive optics, building large telescopes and coronography; interferometers using multiple telescopes; lasers for guide stars and wavelength control; and LIGO and LISA.
ASTR 45400. Image Processing (Analysis)
The courses focuses on how to extract information from astronomical raw images on a pixel basis, in situations involving low source light levels relative to background brightnesses. Specific cases considered include detection of AGN variability, high resolution imaging of galactic nuclei, star-galaxy separation, image shear measurements, supernova detection and characterization, planetary transit photometry and direct planet detection. Techniques for accomplishing such tasks include wavelet analysis, deconvolution, image subtraction, adaptive-optics photometry and interferometry.
ASTR 45500. Machine Learning in Astronomy
This applications-based course will cover major Machine Learning topics applied to astronomy datasets. Topics will include image classification, clustering, and anomaly detection. The course is intended for graduate students and advanced senior undergraduates who have some experience programming in Python.
ASTR 45800. Exoplanets
The study of exoplanets, planets associated with stars other than the Sun, has become one of the most exciting and rapidly evolving areas of modern astronomy. This new course will address general questions concerning the detection and characterization of exoplanets and of what we have already learned about the origin and properties of exoplanetary systems and of how they compare with those of the Solar System. This discussion will be placed in the context of models of planet formation in protoplanetary disks, their structure and composition, and their dynamical interactions with the natal disk, the parent star, and other planets. The course will make use of seminal papers on these topics and will encourage active participation by the students.
ASTR 45900. What Make a Planet Habitable?
*Dorian Abbot, Fred Ciesla (cross-listed as GEOS 32060).*
This course explores the factors that determine how habitable planets form and evolve. We will discuss a range of topics, from the formation of planets around stars and the delivery of water, to the formation of atmospheres, climate dynamics, and the conditions that allow for the development of life and the evolution of complex life. Students will be responsible for reading and discussing papers in peer-reviewed journals each meeting and for periodically preparing presentations and leading the discussion.
ASTR 46100. Dynamics of Exoplanets
Exoplanets are planets that orbit other stars. As most detection methods are indirect, planets' orbital dynamics is key to basic characterization, and it was historically important to confirm their existence. Their surprising orbital properties challenged planet formation and evolution theories, prompting further development of dynamical theories. This course covers orbital mechanics of N-body systems from the short-term, relevant to observations such as transit-timing variations, all the way to billion-year timescales, relevant to the dynamical winnowing of unstable systems. It covers highly eccentric and inclined orbits, scattering and resonant dynamics, planetary orbits in binary star systems, the additional physics of tidal dissipation and orbital migration due to a gas disk, and current research topics.
ASTR 47300. Distant Galaxies
This course will focus on observations of distant galaxies, from the cosmic dawn to the epoch when the star formation rate density peaks. It will explore a range of topics concerning early galaxy formation and evolution including: photometric and spectroscopic properties of star-forming galaxies at high redshifts, the statistics of distant galaxies, the epoch of reionization, the ionization photon budget, formation of supermassive black holes, chemical enrichment in the early universe, and the fossil record of the Local Group.
ASTR 49900. Graduate Research Seminar
The instructor chooses a topic for the seminar and assigns papers that develop the topic from the earliest times to the most recent results. Students each present papers during the course, as assigned, and lead a discussion. The purpose is to give students practice in analyzing the literature and in presenting to their peers, as well to assure breadth in the topics covered during their time at Chicago. The class meets once per week for one hour.