Reviewing the fundamental instrumental techniques and current observational results, this book unveils the mysteries of the physical processes in the central parsec of our Milky Way: the super-massive black hole embedded in a central stellar cluster as well as the gas and dust in the circumnuclear region.

The observations described cover the entire electromagnetic spectrum from decimeter radio-waves to high energy X-ray and γ-rays, and a comprehensive summary of up-to-date astrophysical interpretations is given.

The emphasis is put on observational techniques, image processing aspects, and a detailed presentation of the most cutting-edge work carried out in the near-infrared wavelength regime. These recent results include both the first orbits of stars around the central black hole and the multiwavelength variability of the central source.

Contents:

• Observational Techniques:
• The GC Across the Electromagnetic Spectrum
• NIR Imaging Through the Atmosphere
• Speckle Imaging
• Single Telescope Adaptive Optics
• Cleaning and Deconvolution
• Future IR Interferometry
• Observational Results:
• The Discovery of Sagittarius A*
• Large-Scale Structures at the Galactic Center
• The Circum Nuclear Disk
• The Mini- Spiral
• Radio Filaments
• Near-Infrared Images of the Central Stellar Cluster
• The Radio and Infrared Positional Reference Frames
• Number Density Counts
• Polarization of Filaments and Stars
• Stellar Velocities and Orbital Accelerations
• Spectroscopy
• Star Formation at the Galactic Center?
• Sgr A* Across the Electromagnetic Spectrum
• Astrophysical Results:
• The Stellar Velocity Field
• Scenarios for Star Formation at the Galactic Center
• The Central Dark Mass
• Stability of the Enclosed Dark Mass
• Agglomerations of Exotic Particles?
• The Central Stellar Cusp
• Analysis of Stellar Orbits Near the Central Black Hole
• The Central Black Hole
• Comparison to Nuclei of Other Galaxies
• Massive Black Holes at High Redshifts