High-resolution Millimeter-VLBI Imaging of Sgr A*

Abstract

We present the highest resolution VLBI imaging observations of Sgr A* made at both 7 and 3.5 mm. These data reveal wavelength-dependent intrinsic sizes with an intrinsic emitting region at 3.5 mm of about 1 AU (at a distance of 8 kpc to the Galactic Center). When combined with the lower limit on the mass of Sgr A*, these size measurements provide strong evidence that Sgr A* is a super-massive black hole. We also detected a structural variation which results in an intrinsically symmetrical structure that increases in its intrinsic size by more than 25% at 7 mm.

arXiv comment4 pages, Contribution to the proceedings of the Galactic Center Workshop 2006 "From the Center of the Milky Way to Nearby Low-Luminosity Galactic Nuclei", held in Bad Honnef, Germany on April 18 - 22, 2006. Editors: R. Schoedel (University of Cologne), et al.. To be published in the Journal of Physics: Conference Series by Institute of Physics Publishing

References in corpus (12)

• Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way
• Viewing the Shadow of the Black Hole at the Galactic Center
• Stellar Orbits Around the Galactic Center Black Hole
• The Proper Motion of Sgr A*: II. The Mass of Sgr A*
• The Supermassive Black Hole at the Galactic Center
• A size of ~1 AU for the radio source Sgr A* at the centre of the Milky Way
• Detection of the Intrinsic Size of Sagittarius A* through Closure Amplitude Imaging (includes Online Supporting Material)
• Intrinsic Size OF Sgr A*: 72 Schwarzschild Radii
• Structure of Sagittarius A* at 86 GHz using VLBI Closure Quantities
• The Variability of Sagittarius A* at Centimeter Wavelengths
• Intra-Day Variation of Sagittarius A* at Short Millimeter Wavelengths
• Testing RIAF model for Sgr A* using the size measurements

Cited by in corpus (6)

• Jet-lag in Sgr A*: What size and timing measurements tell us about the central black hole in the Milky Way
• Multiwavelength VLBI observations of Sagittarius A*
• The Circular Polarization of Sagittarius A* at Submillimeter Wavelengths
• Wisps in the Galactic center: NIR triggered observations of the radio source Sgr A* at 43 GHz
• Spherically Symmetric Accretion Flows: Minimal Model with MHD Turbulence
• Micro-arcsecond structure of Sagittarius A* revealed by high-sensitivity 86 GHz VLBI observations