An XMM investigation of non-thermal phenomena in the winds of early-type stars

We propose to observe the hard nonthermal Xray emission from presumably single Otype stars known to display strong nonthermal emission in the radio domain. Theoretical models predict the existence of a small population of relativistic electrons accelerated in strong shocks in the winds of O stars. Given the enormous supply of UV photons from these stars, inverseComptonscattering should generate a substantial nonthermal Xray emission. XMM is the very first Xray observatory that has the sensitivity required to measure this emission. Studying this phenomenon will provide important insight intothe properties of the relativistic electron population in the winds of OB starsand could eventually provide the very first measurement of the magnetic field truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]