X-ray Emission Line Profiles from the Magnetically Confined Wind Shock Model

Date
2003
Journal Title
Journal ISSN
Volume Title
Publisher
Producer
Director
Performer
Choreographer
Costume Designer
Music
Videographer
Lighting Designer
Set Designer
Crew Member
Funder
Rehearsal Director
Concert Coordinator
Moderator
Panelist
Alternative Title
Department
Swarthmore College. Dept. of Physics & Astronomy
Type
Thesis (B.A.)
Original Format
Running Time
File Format
Place of Publication
Date Span
Copyright Date
Award
Language
en_US
Note
Table of Contents
Terms of Use
Full copyright to this work is retained by the student author. It may only be used for non-commercial, research, and educational purposes. All other uses are restricted.
Rights Holder
Access Restrictions
Terms of Use
Tripod URL
Identifier
Abstract
O stars make important contributions to the energy and composition of the interstellar medium through their stellar winds and tendency to become super-novae. The Chandra satellite has recently observed X-ray emission lines from these stellar winds, producing spectra of unprecedented resolution. One of these observed stars is the young star θ1 Orionis C. The X-ray lines from this star are narrow and symmetric, in direct contrast to the line profiles observed from ( Puppis, which has a standard X-ray emitting wind. In addition, observations of Zeeman splitting and optical polarization have detected a magnetic field around this star (Donati et al., 2002). θ1 Orionis C is unusual in that its rotational axis is misaligned from both the magnetic field axis and the observer's axis. This allows us to view this star from all possible angles with respect to the magnetic axis. In order to examine the wind structure producing the narrow, symmetric X-ray emission line profiles from θ1 Orionis C, we calculate analytic and numer-ical models based on an adaptation of the Magnetically Confined Wind Shock (MCWS) model. From these models we are able to create line profiles that can be compared to observed line profiles from θ1 Orionis C. Here we describe the process by which our program creates line profiles from analytic and numerical wind models. We find that our most sophisticated model, a numerical magne-tohydrodynamic (MHD) simulation of a non-isothermal wind that emits X-rays from material with a temperature over 106 K, matches the data well. The char-acteristics of the line profiles from the model and the data are consistent in three important ways: the lines are narrow; the centroids of the line profiles do not shift far from the rest wavelength; and the flux decreases with increasing viewing angle. We conclude that our adaptation of the MCWS model is a good descrip-tion of the wind structure around θ1 Orionis C, and around other hot stars with magnetic fields.
Description
Subjects
Citation