your ID: 0309 
First Name: Zhi-Qiang 
Last Name: Shen 
Affiliation: Shanghai Astronomical Observatory 

Title: High-resolution Millimeter-VLBI Study of Sgr A* 
--A Supermassive Black Hole at the Galactic Center 
Authors: Z.-Q. Shen 
Topic: 1 
Session: oral 

Abstract: 
We present the highest resolution VLBI imaging observations of Sgr A*. 
These data reveal a wavelength-dependent intrinsic size with an intrinsic 
emitting region at 3.5 mm of about 1 AU (at a distance of 8 kc 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 that results in an intrinsically symmetrical 
structure that increases in its intrinsic size by more than 25% at 7 mm.