Is there a Supermassive Black Hole at the Center of the Milky Way?

Abstract

This review outlines the observations that now provide an overwhelming scientific case that the center of our Milky Way Galaxy harbors a supermassive black hole. Observations at infrared wavelength trace stars that orbit about a common focal position and require a central mass (M) of 4 million solar masses within a radius of 100 Astronomical Units. Orbital speeds have been observed to exceed 5,000 km/s. At the focal position there is an extremely compact radio source (Sgr A*), whose apparent size is near the Schwarzschild radius (2GM/c^2). This radio source is motionless at the ~1 km/s level at the dynamical center of the Galaxy. The mass density required by these observations is now approaching the ultimate limit of a supermassive black hole within the last stable orbit for matter near the event horizon.

arXiv commentInvited review submitted to International Journal of Modern Physics D; 23 pages; 10 figures

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Cited by in corpus (45)

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• Micro-Arcsecond Radio Astrometry
• Optical phenomena in brany Kerr spacetimes
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• Multiwavelength VLBI observations of Sagittarius A*
• Discovery of Substructure in the Scatter-Broadened Image of Sgr A*
• Physical laboratory at the center of the Galaxy
• Test of Einstein equivalence principle near the Galactic center supermassive black hole
• Isolated Horizons and Black Hole Entropy in Loop Quantum Gravity
• Adapting a Cryogenic Sapphire Oscillator for Very Long Baseline Interferometry
• A New Perspective of the Radio Bright Zone at The Galactic Center: Feedback from Nuclear Activities
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