David Cohen
Swarthmore College

Talk for MiMeS Meeting#2 in Paris, May 2009

"A critical evaluation of X-ray diagnostics and their relationship to magnetic fields"

The observed x-ray behavior of known magnetic massive stars is distressingly heterogeneous, 
painting a complex picture of the relationship between magnetic fields and x-ray production in
massive stars.  Even in the case of the prototype theta1 Ori C, there are several puzzles that 
remain to be solved.  The situation is more complicated and ambiguous in other magnetic hot 
stars.  In this talk, I will describe several x-ray diagnostics that are often taken to be 
affected by magnetic fields -- spectral hardness, time variability, line profiles, and f/i 
line ratios -- and discuss the uncertainties in their application to real datasets.