Includes bibliographical references (pages 265-286) and index.
Chapter 1. The Galactic Center -- 1.1. Discovery of Sagittarius A* -- 1.2. Radio Morphology of the Central Region -- 1.3. X-ray Morphology of the Central Region -- 1.4. Sagittarius A East -- Chapter 2. The Radio Source Sagittarius A* -- 2.1. Position of Sagittarius A* -- 2.2. Proper Motion -- 2.3. Structure as a Function of Frequency -- Chapter 3. Sagittarius A*'s Spectrum -- 3.1. The Radio Spectrum -- 3.2. Linear and Circular Polarization -- 3.3. Infrared Observations -- 3.4. X-ray Observations -- 3.5. Observed High-Energy Characteristics -- Chapter 4. Variability -- 4.1. Short-Term Variability in the IR and X-rays -- 4.2. Long-Term Variability in the Radio -- Chapter 5. The Central Star Cluster -- 5.1. The Stellar Cusp Surrounding the Black Hole -- 5.2. Stellar Constituents and Dynamics -- 5.3. Stellar Orbits and the Enclosed Mass -- Chapter 6. The Four-Dimensional Spacetime -- 6.1. The Flat Spacetime Metric -- 6.2. Relativistic Transformation of Physical Laws -- 6.3. Accelerated Frames -- 6.4. General Relativity -- 6.5. Particle Orbits and Trajectories -- 6.6. The Kerr Metric -- Chapter 7. Mass Accretion and Expulsion -- 7.1. Sagittarius A*'s Gaseous Environment -- 7.2. Bondi-Hoyle Capture from Distributed Sources -- 7.3. Accretion Close to Sagittarius A* -- 7.4. Magnetic Field Dissipation -- 7.5. A Compact Magnetized Disk -- 7.6. Expulsion of Matter -- Chapter 8. Flares -- 8.1. Flare Physics -- 8.2. Periodicity -- 8.3. General Relativistic Flux Modulations -- Chapter 9. Strong Field Physics -- 9.1. Spin-Induced Disk Precession -- 9.2. Microlensing -- 9.3. Imaging the Shadow of the Black Hole