Are Optically Thick Winds Regulated by the Distribution Over Line Wavelength Rather Than Line Strength?

University Of Iowa, Iowa City IA

Investigators

Abstract

Gayley, Kenneth "Are Optically Thick Winds Regulated by the Distribution Over Line Wavelength Rather Than Line Strength?" AST-0098155 The most massive stars are predestined to end their active lives with a supernova outburst. Prior to this terminal event, such a star undergoes substantial mass loss through radially driven winds that are many orders of magnitude stronger than those associated with stars of smaller mass like the Sun. It is important to understand how these winds operate, not only because of their part in transferring matter and energy into the interstellar medium but also because of the need to fix the initial parameters of the supernova explosion which itself in turn will enrich the interstellar medium with matter and with energy generated deep in the stellar interior. During the course of this award, the PI and his student. will explore those factors which lead to the extremely large mass loss rates in Wolf-Rayet stars. The plan is to work from the assumption that the major opacity factor is the wavelength distribution of the absorption lines in the expanding stellar atmosphere. Detailed calculations will be carried out to see how this drives the extreme mass loss from these stars. ***