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Spectroscopic Influence of Temperature Inhomogeneities

Published online by Cambridge University Press:  30 March 2016

Roger Cayrel  and
Matthias Steffen
Roger Cayrel
Affiliation:
Observatoire de Paris, 61 av. de l’Observatoire F-75014 Paris, France
Matthias Steffen
Affiliation:
Astrophysikalisches Institut Potsdam, Potsdam, Germany

Abstract

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The effect of temperature inhomogeneities on the formation of two oxygen lines and one Fe II line has been investigated based on 2-D radiation hydrodynamics simulations of convection in the atmospheres of metal-poor stars. It was expected that the IR O I triplet lines would be enhanced by the temperature inhomogeneities, more than the forbidden [O I] line or Fe II lines. The actual computations done on two snapshots under the assumption of LTE have not confirmed this expectation, instead suggesting that the main difference between ‘classical’ and ‘dynamical’ atmospheres of metal-poor dwarfs is the significantly cooler mean temperature of the dynamical upper photosphere (τRoss ≾ 0.01).

Type
II. Joint Discussions
Information
Highlights of Astronomy , Volume 12: Highlights of Astronomy. As presented at the XXIVth General Assembly of the IAU, 2000 , 2002 , pp. 423 - 425
Copyright
Copyright © Astronomical Society of Pacific 2002

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