Session 12 - Radio Galaxies, VLBI.
Display session, Monday, January 15
North Banquet Hall, Convention Center

## [12.14] 3mm-VLBI Observations of the Galactic Center

S. Doeleman, A. E. E. Rogers (Haystack Obs.), G. C. Bower, M. C. H. Wright, D. C. Backer (UC Berkeley Radio Astronomy Lab)

April 1995 observations with the CMVA (Coordinated Millimeter VLBI Array) at 3mm wavelength have included, for the first time, the BIMA mm array. We have used the BIMA-KittPeak baseline (up to 400M\lambda) to estimate the size of the compact radio source at the galactic center, Sgr A*.

Our results confirm the size found using the smaller OVRO-KittPeak baseline of \sim 0.2mas. This size is consistent with a point source scattered by an screen of ionized material and follows a \propto \lambda^2 dependence extrapolated from lower frequency observations. We examine the implications of these results using theoretical models of emission in which the radiation is produced via accretion onto a massive black hole.