6533b821fe1ef96bd127bac7
RESEARCH PRODUCT
Testing the companion hypothesis for the origin of the X-ray emission from intermediate-mass main-sequence stars
Giuseppina MicelaSwetlana HubrigBeate StelzerNuria Huélamosubject
PhysicsSpatially resolvedAstrophysics::High Energy Astrophysical PhenomenaAstrophysics (astro-ph)FOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsStarsSpace and Planetary ScienceAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary AstrophysicsMultiplicity (chemistry)Main sequenceAstrophysics::Galaxy Astrophysicsdescription
There is no straightforward explanation for intrinsic X-ray emission from intermediate-mass main-sequence stars. Therefore the observed emission is often interpreted in terms of (hypothesized) late-type magnetically active companion stars. We use Chandra imaging observations to spatially resolve in X-rays a sample of main-sequence B-type stars with recently discovered companions at arcsecond separation. We find that all spatially resolved companions are X-ray emitters, but seven out of eleven intermediate-mass stars are also X-ray sources. If this emission is interpreted in terms of additional sub-arcsecond or spectroscopic companions, this implies a high multiplicity of B-type stars. Firm results on B star multiplicity pending, the alternative, that B stars produce intrinsic X-rays, can not be discarded. The appropriate scenario in this vein is might be a magnetically confined wind, as suggested for the X-ray emission of the magnetic Ap star IQ Aur. However, the only Ap star in the Chandra sample is not detected in X-rays, and therefore does not support this picture.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-02-23 |