Department of Astrophysical Sciences

Chair

Scott D. Tremaine

Associate Chair (Acting Chair/Fall)

David N. Spergel

Associate Chair for Plasma Physics

Ronald C. Davidson

Director of Graduate Studies

James M. Stone

Astronomy

Professor

Neta A. Bahcall

Christopher F. Chyba, also Woodrow Wilson School

Bruce T. Draine

Jeremy Goodman

J. Richard Gott III

James E. Gunn

Gillian R. Knapp

Jeremiah P. Ostriker

Bohdan Paczynski

David N. Spergel

James M. Stone, also Applied and Computational Mathematics

Michael Strauss

Scott D. Tremaine

Edwin L. Turner

Assistant Professor

Alice E. Shapley

Visiting Lecturer with Rank of Professor

Peter Goldreich

Visiting Lecturer

Michael D. Lemonick

Associated Faculty

Lyman Page, Physics

Paul J. Steinhardt, Physics

Plasma Physics

Director of Program and Graduate Studies

Nathaniel J. Fisch

Professor

Ronald C. Davidson

Nathaniel J. Fisch

Robert J. Goldston

Lecturer with Rank of Professor

Samuel A. Cohen

Gregory W. Hammett

Stephen C. Jardin

John A. Krommes

Cynthia K. Phillips

Allan H. Reiman

William M. Tang

Roscoe B. White

Lecturer

Philip C. Efthimion

Richard P. Majeski

Jonathan E. Menard

Hong Qin

Michael C. Zarnstorff

Associated Faculty

Edgar Y. Choueiri, Mechanical and Aerospace Engineering

Szymon Suckewer, Mechanical and Aerospace Engineering

 

The Department of Astrophysical Sciences offers advanced training in astrophysics and plasma physics; under the department’s aegis, an extensive program of graduate research is also conducted at the renowned Princeton Plasma Physics Laboratory (PPPL), located on Princeton’s Forrestal campus. The fascinating discoveries of modern astronomy challenge human understanding of the broadest possible range of physical phenomena. Plasma physics provides the scientific basis for the attainment of an effectively unlimited energy source through controlled thermonuclear fusion as well as a framework for interpreting many fascinating laboratory and astrophysical phenomena. The primary emphasis of the departmental program is on the basic physical understanding of these topics.

Students request admission to either the astronomy section or the plasma physics section of the program. Prior to the general examination they are expected to take a number of nondepartmental courses, usually in physics and mathematics, in addition to a variety of courses within the department. Both the number and the choice of courses are flexible and are worked out with students to satisfy their own interests and assist their preparation for the general examination.

For admission to candidacy for a Ph.D. in the astronomy section, students must complete the following requirements: (1) successfully complete all of the courses required by the department (AST 541, two semesters; AST 542, two semesters; and four additional astronomy graduate-level courses); (2) pass the general examination; and (3) produce at least one paper suitable for submission to a journal as part of a departmental research project. The research supervisor must approve the paper.

Students are not admitted for an M.A. degree. However, in rare circumstances, an M.A. may be awarded when students complete two of the following three requirements: (1) successfully complete all of the required courses described above; (2) pass the general examination; and (3) produce at least one paper suitable for submission to a journal as part of a departmental research project. The research supervisor must approve the paper.

A student undertakes several research projects during the first two years, normally within the research area of the section in which he or she is enrolled. Such projects are considered essential to the educational process, by providing students with the opportunity to learn by working in close association with an active research scientist. Usually the results of such research are significant enough to warrant publication.

Research within the astronomy section concentrates on gaining an understanding of the fundamental processes that govern the evolution and the formation of planets, stars, galaxies, and the universe. There is a strong tradition of theoretical research in a wide range of topics, including galaxy formation and evolution, numerical hydrodynamics, the origin of structure in the early universe, plasma astrophysics, stellar structure and evolution, stellar systems, the physics of the interstellar medium, and extrasolar planets. Observational work is carried out with a wide variety of ground-based telescopes, including the ARC 3.5-meter telescope. Department members are also involved with research using data from NASA’s Hubble Space Telescope and other space-based observatories. Princeton is one of the lead partners in NASA’s WMAP satellite and in the Sloan Digital Sky Survey. Observational work includes studies of large-scale structure, active galactic nuclei, stars and sub-stellar objects, large-scale optical surveys, gravitational lenses, the interstellar medium, and the structure of galaxies.

Research in the plasma physics section concentrates on fundamental physics problems pertinent to this discipline, and on questions raised in the controlled thermonuclear-fusion program, energetic laser-plasma and X-ray laser experiments, plasma-surface interaction studies, plasma thruster and other plasma devices, and astrophysics. The program includes theoretical and laboratory studies of the basic properties of plasmas, including the heating and magnetic confinement of plasmas at temperatures on the order of 100 million degrees K. Nonlinear plasma and optical processes and plasma diagnostics also receive close attention. PPPL offers unsurpassed facilities for experimental research in these areas, while a strong theoretical program is given additional support through access to the most powerful computers.

While there are no strict rules for admission, it is highly desirable that applicants for plasma physics have a strong background in physics, applied mathematics, or engineering and sufficient preparation overall to take basic graduate courses in theoretical physics, for example PHY 501, 505, and 511. In the astronomy section, students with a strong undergraduate background in physics are ideally prepared, but students from other undergraduate concentrations will be considered. Courses in plasma physics or astronomy are very helpful but are not required for admission to either section.

Equipment and Facilities

The departmental offices, together with lecture and seminar rooms, are located in William Charles Peyton Hall, which also contains laboratories for the development of astronomical instrumentation. The department has a large Beowulf cluster, approximately 100 scientific workstations, and benefits from campus computing facilities such as a 64-processor Silicon Graphics Altix and a 2048-processor IBM Blue Gene. The astronomy library subscribes to all the major astronomical journals and provides access to electronic astronomical databases. Princeton is a member of the Astrophysical Research Consortium (ARC), which operates a 3.5-meter telescope at Sacramento Peak, New Mexico. Princeton is also a member of the Sloan Digital Sky Survey consortium, which is engaged in a five-year survey to map the universe out to a redshift of 0.2. The survey will also produce a five-color digital photometric map of the sky above galactic latitude 30 degrees. Princeton is a lead institution for the Wilkinson Microwave Anisotropy Probe (WMAP) satellite and the Atacama Cosmology Telescope (ALT), both of which are designed to study the cosmic microwave background with unprecedented detail.

Studies of basic plasma physics and the possibilities of controlled thermonuclear power were initiated at Princeton University in 1951. PPPL is now the largest center for plasma research in the United States. Facilities at the laboratory for experimental research include an ever-evolving family of extremely powerful tokamak devices. In December 1982, the Tokamak Fusion Test Reactor (TFTR) opened the path to physics and technology studies in a totally unexplored range of plasma parameters. Valuable data from TFTR, recently closed, is still being analyzed. At the same time, new midsize confinement devices are being built, and a number of smaller experimental systems are also available both at PPPL and in campus laboratories, including laboratories for research on semiconductor and materials-fabrication process plasmas, plasma thrusters, the curious phenomenon of magnetic reconnection, nonlinear optics, multiphoton processes, and unclassified research on X-ray lasers. Theoretical research includes the areas of magnetic confinement of hot plasma as well as intense laser-plasma interactions, magnetospherical and astrophysical plasmas, and various plasma devices. Many theoretical projects involve intensive computation, and students in the program have access via the Energy Sciences Network (ESNET) to a variety of high-performance systems, including massively parallel computers. From their first week, graduate students participate in both the experimental and the theoretical research programs at the laboratory using all of these facilities.

Students interested in the engineering aspects of plasma physics and fusion research should consult the section on the Program in Plasma Science and Technology found in this catalog.

Courses

AST 513 Stellar Systems

Scott D. Tremaine

An introduction to the distribution and kinematics of stars in the solar neighborhood, the overall structure of our galaxy, and the properties of external galaxies; theory of orbits; theory of the equilibrium and stability of stellar systems; relaxation, dynamical friction, and the Fokker-Planck equation; spiral structure; mergers of galaxies; evolution of N-body systems.

AST 514 Structure of the Stars

Jeremy Goodman, Bohdan Paczynski

Theoretical and numerical analysis of the structure of stars and their evolution. Topics include a survey of physical processes important for stellar interiors (equation of state, transport phenomena, nuclear reactions); macroscopic properties of stars and their stability; evolution of single and binary stars; mass loss and accretion of matter; and accretion disks. Various methods of distance determinations for stars and their relation to cosmology are presented. Recent developments such as gamma-ray bursts and gravitational microlensing are presented, and prospects for future progress are discussed.

AST 517 Diffuse Matter in Space

Bruce T. Draine

Discussion of the important physical processes in the interstellar medium, including heating and cooling, atomic and molecular excitation, chemical reactions, ionization and recombination, radiative transfer, fluid dynamics, and physics of interstellar dust. Review of observational evidence from which properties of the interstellar medium are inferred. Problems considered include physical conditions in interstellar clouds, interstellar shock waves, effects of cosmic rays, magnetic fields, and star formation.

AST 520 High-Energy Astrophysics

Jeremy Goodman, David N. Spergel, James M. Stone

Astrophysical applications of electrodynamics, special and general relativity, nuclear and particle physics are studied. Topics may include synchrotron emission and absorption, comptonization, pair plasmas, jets, extragalactic radio sources, compact objects, cosmic rays, and neutrino astrophysics.

AST 522 Extragalactic Astronomy

James E. Gunn, Staff

A survey course, covering current areas of research in extragalactic astronomy, including an introduction to cosmology and the formation of structure, galaxy formation, and evolution, including chemical evolution, the microwave background, active galactic nuclei, and clusters. Approximately half of the course consists of guest lectures by other faculty members covering their areas of expertise.

AST 523 Scientific Computation in Astrophysics

James M. Stone

A broad introduction to scientific computation, using examples drawn from astrophysics. From computer science, practical topics, including processor architecture, parallel systems, structured programming, and scientific visualization are presented in tutorial style. Basic principles of numerical analysis, including sources of error, stability, and convergence of algorithms are explored. The theory and implementation of techniques for linear and nonlinear systems of equations, ordinary and partial differential equations are demonstrated, with problems in stellar structure and evolution, stellar and galactic dynamics, and cosmology.

AST 541 Seminar in Theoretical Astrophysics

Scott D. Tremaine

This seminar is designed to stimulate students in the pursuit of research. Participants discuss critically papers given by seminar members. Ordinarily, several staff members also participate. Often topics are drawn from published data that present unsolved puzzles of interpretation.

AST 542 Seminar in Observational Astrophysics

Gillian R. Knapp

This seminar considers in detail a variety of observational techniques, with an emphasis on what they can and cannot accomplish with regard to various specific astrophysical problems. Several staff members with interests in different areas of observational astronomy participate.

AST 545, 546 Special Topics in Astrophysics

Staff

A series of lectures on advanced problems in the field. For this course, topics of current special interest are selected, such as the interiors of the planets, extragalactic research, high-energy astrophysics, or astronomical experiments on rockets and satellites. Often this course is given by a visiting astronomer.

See the Program in Plasma Physics for additional courses specifically related to the study of plasma physics.