July 11-15, 2011
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A CHARA Array Survey of the Circumstellar Environments of Rapidly Rotating Be Stars

Yamina Touhami (CHARA/GSU)

D. R. Gies, G. H. Schaefer, N. D. Richardson, S. J. Williams, E. D. Grundstrom, & M. V. McSwain

We present the first spatially resolved observations of circumstellar envelopes of 25 bright northern Be stars. The survey was performed with the CHARA Array interferometer in the K-band at intermediate and long baselines. The interferometric visibilities are well fitted by an optically thick disk model where the gas density steeply decreases with the radius. Physical and geometrical parameters such as the density profile, the inclination, and the position angle of the circumstellar disks are determined, and we find that the density exponent varies between n ~ 2.4-3.2, which is consistent with previous IRAS measurements. In addition to the interferometric observations, we also present simultaneous optical and near-IR spectrophotometry data taken at Lowell observatory. We show that the thick disk model reproduces well the observed disk IR-continuum excess. By combining the projected rotational velocity of the Be star with the disk inclination derived from interferometry, we can estimate the equatorial rotational velocities of these Be stars.

Mode of presentation: poster