The Position, Motion, and Mass of Sgr A*
Abstract
We report progress on measuring the position of Sgr A* on infrared images, placing limits on the motion of the central star cluster relative to Sgr A*, and measuring the proper motionof Sgr A* itself. The position of Sgr A* has been determined to within 10 mas on infrared images. To this accuracy, the gravitational source (sensed by stellar orbits) and the radiative source (Sgr A*) are coincident. Proper motions of four stars measured both in the infrared and radio indicate that the central star cluster moves with Sgr A* to within 70 km/s. Finally, combining stellar orbital information with an upper limit of 8 km/s for the intrinsic proper motion of Sgr A* (perpendicular to the Galactic plane), we place a lower limit on the mass of Sgr A* of 4 x 10^5 Msun.
Cite
@article{arxiv.astro-ph/0304095,
title = {The Position, Motion, and Mass of Sgr A*},
author = {M. J. Reid and K. M. Menten and R. Genzel and T. Ott and R. Schoedel and A. Eckart and A. Brunthaler},
journal= {arXiv preprint arXiv:astro-ph/0304095},
year = {2009}
}
Comments
7 pages, 4 figures