Volume 449, Number 3, April III 2006
|Page(s)||L41 - L44|
|Published online||24 March 2006|
Letter to the Editor
Ca II K polarization as a diagnostic of temperature bifurcation
Institute of Astronomy, ETH Zurich, 8092 Zurich, Switzerland e-mail: [holzreuter;fluri;stenflo]@astro.phys.ethz.ch
2 Faculty of Mathematics & Science, University of Zurich, 8057 Zurich, Switzerland
Accepted: 2 February 2006
Aims.We compute the linearly polarized spectrum of K caused by coherent scattering and exploit the line for chromospheric diagnosis, with particular attention to temperature bifurcation, by comparing the theory with solar observations.Methods.We numerically solve the statistical equilibrium equations and the radiative transfer equation taking into account polarized coherent scattering with partial frequency redistribution. All calculations are performed in 1D within a plane-parallel atmosphere.Results.We find strong evidence of a chromospheric temperature bifurcation. This suggests that the linearly polarized spectrum of K might become a valuable tool to study cool components and the dynamics of the chromosphere independently of observations of molecular CO lines and millimeter and sub-millimeter continua.
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.