The study of AGN is one of the most dynamic areas of contemporary astronomy, involving one-fifth of all research astronomers. This textbook provides a systematic review of the observed properties of AGN across the entire electromagnetic spectrum, examines the underlying physics, and shows how the brightest AGN--quasars--can be used to probe the farthest reaches of the Universe. This timely textbook is a clear, comprehensive and self-contained introduction to active galactic nuclei (AGN)--for advanced undergraduates and graduate students in astronomy and physics.

Foundations of Astrophysics provides a contemporary and complete introduction to astrophysics for astronomy and physics majors. With a logical presentation and conceptual and quantitative end-of-chapter problems, the material is accessible to introductory astrophysics students taking a two-semester survey course.