Escape probability treatment of doublet resonance lines in expanding stellar winds

Journal Article · Thu Apr 01 04:00:00 EST 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159825· OSTI ID:5100548

Olson, G L

When stellar winds have expansion velocities greater than the velocity separation between doublet line transitions, the line source function of the component with the longer wavelength depends on nonlocal values of the other component's source function. By using the Sobolev approximation and escape probability methods, the nonlocal radiative coupling for the case of spherically symmetric outflow with a monotonically increasing velocity can be solved explicitly and efficiently. This case is directly applicable to the doublet P Cygni type profiles observed in the ultraviolet spectra of O and B stars and leads to an improved determination of the line strengths. The nonlocal coupling also modifies the radiative forces that act on the mass outflow. Examples of how the nonlocal radiative coupling changes the line source functions, the line profiles, and the radiative forces are presented.

• Research Organization: Joint Institute for Laboratory Astrophysics, University of Colorado and National Bureau of Standards
• OSTI ID: 5100548
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 255:1; ISSN ASJOA
• 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
COUPLING
ENERGY-LEVEL TRANSITIONS
EXPANSION
FUNCTIONS
RADIATION TRANSPORT
RESONANCE
SPECTRAL FUNCTIONS
STARS
STELLAR RADIATION
STELLAR WINDS
VARIABLE STARS