Statistical Analysis of Interferometric Measurements of Axis Ratios for Classical Be Stars

Abstract

This work presents a novel method to estimate the effective opening angle of CBe star disks from projected axis ratio measurements, obtained by interferometry using Bayesian statistics. A Monte Carlo scheme was used to generate a large set of theoretical axis ratios from disk models using different distributions of disk densities and opening angles. These theoretical samples were then compared to observational samples, using a two-sample Kolmogorov-Smirnov test, to determine which theoretical distribution best reproduces the observations. The results suggest that the observed ratio distributions in the K-, H-, and N-band can best be explained by the presence of thin disks, with opening half-angles of the order of 0.15${}^{\circ }$ to 4.0${}^{\circ }$. Results for measurements over the H$\alpha$ line point toward slightly thicker disks, 3.7${}^{\circ }$ to 14${}^{\circ }$, which is consistent with a flaring disk predicted by the viscous disk model.

arXiv commentAccepted for publication in ApJ, 10 pages, 13 figures

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Cited by in corpus (5)

• The X-ray emission of the gamma Cassiopeiae stars
• The effects of stellar rotation along the main sequence of the 100 Myr old massive cluster NGC 1850
• Spectro-interferometric observations of a sample of Be stars. Setting limits to the geometry and kinematics of stable Be disks
• Optical spectroscopy of Be/gamma-ray binaries
• Stellar Inclination Angles from Be Star H$\alpha$ Emission-Line Profiles