Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-09-18
Astrophys.J.654:527-543,2006
Astronomy and Astrophysics
Astrophysics
ApJ in press (2007 Jan 1), 55 pages, 14 figures
Scientific paper
10.1086/509144
We present the first K'-band, long-baseline interferometric observations of the northern Be stars gamma Cas, phi Per, zeta Tau, and kappa Dra. The measurements were made with multiple telescope pairs of the CHARA Array interferometer, and in every case the observations indicate that the circumstellar disks of the targets are resolved. We fit the interferometric visibilities with predictions from a simple disk model that assumes an isothermal gas in Keplerian rotation. We derive fits of the four model parameters (disk base density, radial density exponent, disk normal inclination, and position angle) for each of the targets. The resulting densities are in broad agreement with prior studies of the IR excess flux and the resulting orientations generally agree with those from interferometric H-alpha and continuum polarimetric observations. We find that the angular size of the K' disk emission is smaller than that determined for the H-alpha emission, and we argue that the difference is the result of a larger H-alpha opacity and the relatively larger neutral hydrogen fraction with increasing disk radius. All the targets are known binaries with faint companions, and we find that companions appear to influence the interferometric visibilities in the cases of phi Per and kappa Dra. We also present contemporaneous observations of the H-alpha, H-gamma, and Br-gamma emission lines. Synthetic model profiles of these lines that are based on the same disk inclination and radial density exponent as derived from the CHARA Array observations match the observed emission line strength if the disk base density is reduced by approximately 1.7 dex.
Jr.
Aufdenberg Jason Paul
Bagnuolo William G.
Baines Ellyn K.
Berger David Harold
No associations
LandOfFree
CHARA Array K'-band Measurements of the Angular Dimensions of Be Star Disks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with CHARA Array K'-band Measurements of the Angular Dimensions of Be Star Disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CHARA Array K'-band Measurements of the Angular Dimensions of Be Star Disks will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-646920