The emission lines in the ultra-violet spectrum of Beta Lyrae

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6700266

Mazzali, P A

The properties of the non-degenerate interacting binary system of beta Lyrae was investigated by studying its mass loss features. After reviewing the most noteworthy characteristics of this famously peculiar object, the typical wind signatures were examined: the UV emission lines, observed in high dispersion by IUE. These lines can be divided into two groups: one includes the superionized hot star wind resonances, displaying P-Cygni profiles superimposed to broad emission features; the other includes lines of moderately ionized species, showing pure P-Cygni profiles. After reviewing the theories of radiatively driven stellar winds and line formation, the 3D extension of Sobolev theory, designed to calculate radiative transfer and emerging line profiles in winds where stellar rotation and angular momentum conservation in the flow are included, was described. This model represents more accurately the physics of beta Lyrae. The models are able to predict the stellar rotational rate from the shape of the profiles, showing that rotation cannot be neglected in the modelling of P-Cygni lines. Finally, applying the self-consistent NLTE and hydrodynamic codes developed by Kudritzki, Pauldrach and Puls at the Munich Sternwarte, the winds of the two stars in the system were modeled.

• Research Organization: California Univ., Los Angeles, CA (USA)
• OSTI ID: 6700266
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR MOMENTUM
BINARY STARS
DATA
EMISSION SPECTRA
FLUID MECHANICS
HYDRODYNAMICS
INFORMATION
MATHEMATICAL MODELS
MECHANICS
NUMERICAL DATA
SPECTRA
STAR MODELS
STARS
STELLAR ACTIVITY
STELLAR WINDS
THEORETICAL DATA
ULTRAVIOLET SPECTRA