Two-dimensional particle transport in HgMn and FmAm stars

Abstract

view Abstract Citations (54) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Two-dimensional Particle Transport in HgMn and FmAm Stars Charbonneau, Paul ; Michaud, Georges Abstract Detailed two-dimensional diffusion calculations of helium are carried out to determine the maximum equatorial rotational velocity allowing the gravitational settling of He. Once the He abundance has decreased sufficiently in the superficial convection zones, the He convection zone disappears, abundance anomalies become large, and the HgMn and FmAm phenomena appear. The limiting equatorial velocity is found to be 75 and 100 km s-1, respectively, for HgMn and FmAm stars. It depends mainly on gravity, becoming much smaller as soon as gravity goes down. The observed upper limit being ≡100 km s-1, the agreement is quite satisfactory. These results are very similar to those obtained with the one-dimensional approximation and justify the use of those results. Publication: The Astrophysical Journal Pub Date: April 1988 DOI: 10.1086/166238 Bibcode: 1988ApJ...327..809C Keywords: A Stars; Abundance; Particle Motion; Peculiar Stars; Stellar Interiors; Stellar Rotation; Computational Astrophysics; Diffusion Coefficient; Heavy Elements; Interstellar Magnetic Fields; Astrophysics; CONVECTION; DIFFUSION; STARS: ABUNDANCES; STARS: INTERIORS; STARS: PECULIAR A; STARS: ROTATION; TURBULENCE full text sources ADS |