Sub-milliarcsecond Imaging of SgrA* and M87

Abstract

We present and discuss new result from mm-VLBI observations of M87 and SgrA*, using the Global mm-VLBI array (GMVA). New 3mm-VLBI images of the inner jet of M87 are presented, showing details with a spatial resolution down to 15 Schwarzschild radii. This resolution corresponds to a similar spatial resolution (in terms of R_s) obtained for Sgr A*. We discuss existing and new size determinations for this source provided by mm-VLBI at wavelengths of 3, 2, and 1.4 mm. With respect to the morphological difference between Sgr A* and M87 (the latter exhibits a long jet), a comparison of the sub-milliarcsecond structures seen with mm-VLBI may lead to a better understanding of the astro-physical processes acting in the vicinity of super-massive black holes.

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. Paper contains 7 pages and 6 figures