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Chemical abundances in cool metal rich disk dwarf stars

Thorén, P. and Feltzing, Sofia LU (2000) In Astronomy and Astrophysics 363. p.692-704
Abstract
The present study of spectra of twelve metal-rich cool dwarf stars, carefully selected in order to cover a range of temperatures ( K), is a follow up on Feltzing & Gustafsson (1998) with the aim to understand the apparent over-ionization and anomalous elemental abundances found by them for the K dwarf stars in their sample.



Our method of analysis employs synthetic spectra of the full spectrum both to constrain the continuum level and to derive abundances. It is shown that by using this method and imposing a strict excitation equilibrium (possible to do because of the care in selection of observed Fe I lines) we are able to show that metal-rich K dwarf stars do not show anomalous stellar abundances, as indicated in... (More)
The present study of spectra of twelve metal-rich cool dwarf stars, carefully selected in order to cover a range of temperatures ( K), is a follow up on Feltzing & Gustafsson (1998) with the aim to understand the apparent over-ionization and anomalous elemental abundances found by them for the K dwarf stars in their sample.



Our method of analysis employs synthetic spectra of the full spectrum both to constrain the continuum level and to derive abundances. It is shown that by using this method and imposing a strict excitation equilibrium (possible to do because of the care in selection of observed Fe I lines) we are able to show that metal-rich K dwarf stars do not show anomalous stellar abundances, as indicated in Feltzing & Gustafsson (1998), and can, with reasonable efforts, be analyzed in order to increase the number of metal-rich stars with useful chemical abundances.



With abundance analysis by means of spectrum synthesis and assuming Local Thermodynamic Equilibrium (LTE) the abundances of Na, Si, Ca, Sc, Ti, V, Cr, Fe, Co, Ni, and Nd have been derived. Also ionization balance is satisfied for Fe and Cr after correcting the stellar effective temperatures such that both ionization and excitation equilibrium were satisfied.



In addition, spectra from five cool dwarf stars of the Feltzing & Gustafsson (1998) sample have been analyzed with the methods used in this work. They show essentially the same abundance patterns as the new stars in this sample. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
stars: late-type stars: abundances
in
Astronomy and Astrophysics
volume
363
pages
692 - 704
publisher
EDP Sciences
external identifiers
  • Scopus:0000570251
ISSN
1432-0746
language
English
LU publication?
yes
id
454bd2fd-eeaa-4529-9fe8-a7fa118a45da (old id 113703)
alternative location
http://aa.springer.de/bibs/0363002/2300692/small.htm
date added to LUP
2007-07-20 14:09:45
date last changed
2016-10-13 04:48:32
@misc{454bd2fd-eeaa-4529-9fe8-a7fa118a45da,
  abstract     = {The present study of spectra of twelve metal-rich cool dwarf stars, carefully selected in order to cover a range of temperatures ( K), is a follow up on Feltzing &amp; Gustafsson (1998) with the aim to understand the apparent over-ionization and anomalous elemental abundances found by them for the K dwarf stars in their sample.<br/><br>
<br/><br>
Our method of analysis employs synthetic spectra of the full spectrum both to constrain the continuum level and to derive abundances. It is shown that by using this method and imposing a strict excitation equilibrium (possible to do because of the care in selection of observed Fe I lines) we are able to show that metal-rich K dwarf stars do not show anomalous stellar abundances, as indicated in Feltzing &amp; Gustafsson (1998), and can, with reasonable efforts, be analyzed in order to increase the number of metal-rich stars with useful chemical abundances.<br/><br>
<br/><br>
With abundance analysis by means of spectrum synthesis and assuming Local Thermodynamic Equilibrium (LTE) the abundances of Na, Si, Ca, Sc, Ti, V, Cr, Fe, Co, Ni, and Nd have been derived. Also ionization balance is satisfied for Fe and Cr after correcting the stellar effective temperatures such that both ionization and excitation equilibrium were satisfied.<br/><br>
<br/><br>
In addition, spectra from five cool dwarf stars of the Feltzing &amp; Gustafsson (1998) sample have been analyzed with the methods used in this work. They show essentially the same abundance patterns as the new stars in this sample.},
  author       = {Thorén, P. and Feltzing, Sofia},
  issn         = {1432-0746},
  keyword      = {stars: late-type  stars: abundances},
  language     = {eng},
  pages        = {692--704},
  publisher    = {ARRAY(0x57a6a90)},
  series       = {Astronomy and Astrophysics},
  title        = {Chemical abundances in cool metal rich disk dwarf stars},
  volume       = {363},
  year         = {2000},
}