6533b81ffe1ef96bd1278447

RESEARCH PRODUCT

Search for Low-mass Companions to X-ray Emitting A-type Stars

Giuseppina MicelaM. HünschBeate StelzerBeate StelzerNuria Huélamo

subject

PhysicsAstrophysics::High Energy Astrophysical PhenomenaAstronomyAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsA-type main-sequence starStarsDynamo theoryROSATAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary AstrophysicsLow MassAstrophysics::Galaxy AstrophysicsVisual binary

description

There is no obvious theory that would explain X-ray emission from main-sequence A-type stars. Therefore, the X-ray emission identified with these stars on basis of low spatial resolution X-ray observations is usually attributed to magnetic activity from unknown late-type companion stars. We systematically study the literature and public 2MASS data in search for binaries among A stars. This way, we identify new candidate counterparts for the X-ray sources in at least 60% of the A-type stars claimed to be detected in the ROSAT All-Sky Survey. There is marginal evidence that this fraction decreases from early to late A spectral type, possibly indicating the onset of intrinsic X-ray emission for the latest A stars which may have deep enough convection zones to support magnetic activity.

yearjournalcountryeditionlanguage
2007-10-12
https://doi.org/10.1007/978-3-540-74745-1_38