Date of Award


Document Type

Restricted Thesis

Terms of Use

© 2003 Roban H. Kramer. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Physics & Astronomy Department

First Advisor

David H. Cohen


X-ray emission from hot (O- and B-type) stars is a long-standing astrophysical puzzle. High-resolution x-ray spectroscopy of hot stars resolves emission line profile shapes, offering direct insight into the dynamics and spatial distribution of the x-ray-emitting plasma. The O supergiant ζ Puppis shows broad, blueshifted, and asymmetric line profiles, generally consistent with the wind-shock picture of OB star X-ray production. Here, for the first time, this is demonstrated quantitatively by fitting a spherically-symmetric phenomenological wind model to a Chandra spectrum of ζ Puppis. The results of the fits to eight lines are presented here. Statistically good fits to seven of the lines are achieved, with extracted parameters providing constraints on the amount of absorption in the wind and the minimum radius of x-ray emission. The results indicate that a modest amount of wind attenuation is required, which is inconsistent with previous theoretical calculations of continuum optical depths. The implications of these results are discussed in light of other recent observational and theoretical work.