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What is Sgr A∗?

Published online by Cambridge University Press:  25 May 2016

H. Falcke
H. Falcke*
Affiliation:
Max-Planck-Institut für Radioastronomie (MPIfR), Auf dem Hügel 69, D-53121 Bonn, Germany E-mail: HFalcke@mpifr-bonn.mpg.de (hfalcke@astro.umd.edu)

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Sgr A∗ is the unique 1 Jy flat spectrum radio point source located at the dynamical center of the Galaxy and in the very center of the central star cluster (Eckart et al. 1993). Due to its unusual appearance it has long been speculated that this source is powered by a supermassive black hole–an object whose presence has been suspected to reside in the nuclei of many other galaxies as well. Its mass is believed to be as large as M • ∼ 2 m 106M⊙ (e.g. Genzel & Townes 1987) while a lower limit of M • > 200–2000M ⊙ can be inferred from the low proper motion of Sgr A∗ (Backer – this volume). The currently best dynamical arguments for the million solar mass black hole stem from detailed stellar kinematic studies (Haller et al. 1995).

Type
Chapter 3: What is the Nature of the Center of the Galaxy?
Information
Symposium - International Astronomical Union , Volume 169: Unsolved Problems of the Milky Way , 1996 , pp. 169 - 180
Copyright
Copyright © Kluwer 1996 

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