uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Effects of line-blocking on the non-LTE Fe I spectral line formation
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics.
2005 (English)In: Astronomy & Astrophysics, Vol. 442, 643- p.Article in journal (Refereed) Published
Abstract [en]

The effects of background line opacity (line-blocking) in statistical equilibrium calculations for Fe in late-type stellar atmospheres have been investigated using an extensive and up-to-date model atom with radiative data primarily from the iron Project. The background metal line opacities have been computed using data from the marcs stellar model atmospheres. While accounting for this line opacity is important at solar metallicity, the differences between calculations including and excluding line-blocking at low metallicity are insignificant for the non-local thermodynamic equilibrium (non-LTE) abundance corrections for Fe I lines. The line-blocking has no impact on the non-LTE effects of Fe II lines. The dominant uncertainty in Fe non-LTE calculations for metal-poor stars is still the treatment of the inelastic H I collisions, which here have been included using scaling factors to the classical Drawin formalism, and whether or not thermalisation of the high Fe I levels to Fe II ground state should be enforced. Without such thermalisation, the Fe I non-LTE abundance corrections are substantial in metal-poor stars: about 0.3 dex with efficient (i.e. Drawin-like) H I collisions and <0.5 dex without. Without both thermalisation and H I collisions, even Fe II lines show significant non-LTE effects in such stars.

Place, publisher, year, edition, pages
2005. Vol. 442, 643- p.
Keyword [en]
line: formation, Sun: abundances, stars: abundances, stars: individual: Procyon, stars: individual: HD 140283, stars: individual: G64-12
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:uu:diva-77629DOI: doi:10.1051/0004-6361:20053363OAI: oai:DiVA.org:uu-77629DiVA: diva2:105541
Available from: 2006-03-15 Created: 2006-03-15 Last updated: 2011-01-11

Open Access in DiVA

No full text

Other links

Publisher's full texthttp://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?bibcode=2005A%26A...442..643C&amp;db_key=AST&amp;data_type=HTML&amp;format=&amp;high=4417f8d19f19630

Search in DiVA

By author/editor
Collet, Remo
By organisation
Department of Astronomy and Space Physics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 199 hits
ReferencesLink to record
Permanent link

Direct link