Date of Award


Document Type

Restricted Thesis

Terms of Use

© 2004 Geneviève de Messières. 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


How do hot stars produce X-rays? The two major theories involve radiatively driven wind shocks or magnetic coronal heating. We have acquired a high-resolution spectrum of the nearby B giant ε Canis Majoris, from the Reflection Grating Spectrometer instrument of the XMM-Newton space telescope. Due to its brightness, ε CMa provides a valuable opportunity to test these theories. We fit emission lines from the spectrum in order to draw conclusions about the conditions of velocity and height under which X-rays were generated. The emission lines indicate that the X-ray-emitting plasma has an average speed of 162 km s⁻¹. Analysis of helium-like F/I ratios yields a radius of emission between 1 and 2.1 R*. Characteristic plasma temperatures from a global fit are between 2 and 6 MK.