X-ray Spectroscopy of Chemically Peculiar B Stars,
Their Unseen Companions
Department of Physics
Haifa, 32000 Israel
Late type B stars are not supposed to emit X-rays. Their apparent
detection by X-ray telescopes gives rise to the companion hypothesis.
We will present spectroscopic methods for testing this hypothesis
and dwell on the importance of the atomic data used, the methods
for obtaining it, and on its accuracy.
We will apply these methods to high-resolution Chandra and
XMM-Newton observations of the chemically peculiar late-type
B star mu Lep and show that, indeed, in this case the X-rays
can be traced back to a previously unresolved companion (mu Lep B), whose X-ray spectrum resembles
that of a coronal source.
We will present evidence that supports mu
Lep B being a pre-main-sequence star, most likely of the non-accreting