Open AccessModelling the H Lyman lines in evolved late‐type stars
Author(s) -
Sim S.A.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04632.x
Subject(s) - physics , subgiant , stars , astrophysics , stellar atmosphere , atmospheric models , hydrostatic equilibrium , line (geometry) , atmospheric model , astronomy , ionosphere , meteorology , geometry , mathematics , globular cluster
The importance of partial redistribution (PRD) in the modelling of the Lyman α and Lyman β emission lines of hydrogen in stellar atmospheres is examined using simple atmospheric models of a range of late‐type stars. These models represent the subgiant Procyon (F5 IV–V), and the two giants β Gem (K0 III) and α Tau (K5 III). These stars are selected to span a wide range of surface gravities: 1.25< log g<4.00 . The calculations are performed using the computer code multi with the modifications made by Hubeny & Lites. It is found that PRD effects are highly significant, both in the direct prediction of the Lyman line profiles and in the application of hydrostatic equilibrium to calculate the atmospheric electron density in static atmospheric models.