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Sgr A*: Observations, Models, and Imaging of the event horizon with VLBI

Published online by Cambridge University Press:  13 May 2016

Heino Falcke
Affiliation:
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn, Germany
Sera Markoff
Affiliation:
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn, Germany
Peter L. Biermann
Affiliation:
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn, Germany
Thomas P. Krichbaum
Affiliation:
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn, Germany
Fulvio Melia
Affiliation:
Physics Department and Steward Observatory, The University of Arizona, Tucson, AZ 85721
Eric Agol
Affiliation:
Theoretical Astrophysics, Caltech MS 130-33, 1200 E. California Blvd., Pasadena, CA 91125
Geoffrey Bower
Affiliation:
Radio Astronomy Laboratory, University of California, Berkeley, CA 94720

Abstract

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We show and discuss results and prospects of high-resolution imaging of the supermassive black hole candidate Sgr A*. We also briefly review the latest observational and theoretical progress for this source. The latest millimeter-VLBI observations show compact radio emission from within a region of about 15 Schwarzschild radii. This compact component is most likely responsible for the so-called sub-mm bump in the spectrum and perhaps even for the recently discovered circular polarization discovered up to 43 GHz and some X-ray emission through synchrotron self-Compton emission. Most importantly, however, the sub-mm emission from Sgr A* opens the door to observe, for the first time, the event horizon of a black hole directly with VLBI at sub-mm wavelengths.

Type
The Inner Regions of Galaxies
Copyright
Copyright © Astronomical Society of the Pacific 2001 

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