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An abundance study of the transition beetween the galactic thick and thin disc

Sandell, Johan LU (2009) In Lund Observatory Examensarbeten ASTM31 20091
Lund Observatory
Abstract
Detailed abundance analysis of 41 F and G type dwarf stars located in the solar neighborhood are presented. The stellar sample was selected to have kinematics intermediate between the Galactic thin and thick discs. The stars have been observed with the NOT telescope at La Palma, Spain in March 2006 and the ESO 2.2 m telescope at La Silla, Chile between October 1, 2004 and March 31, 2005. Abundance results show good agreement with the previous study by Bensby et al. (2003). For some elements, the inbetween stars represent a fairly smooth transition between the thick disc and the thin disc, which would favor a formation of a thick disc in the Galaxy without a merger event. Also a kinematically independent investigation of the galactic disc... (More)
Detailed abundance analysis of 41 F and G type dwarf stars located in the solar neighborhood are presented. The stellar sample was selected to have kinematics intermediate between the Galactic thin and thick discs. The stars have been observed with the NOT telescope at La Palma, Spain in March 2006 and the ESO 2.2 m telescope at La Silla, Chile between October 1, 2004 and March 31, 2005. Abundance results show good agreement with the previous study by Bensby et al. (2003). For some elements, the inbetween stars represent a fairly smooth transition between the thick disc and the thin disc, which would favor a formation of a thick disc in the Galaxy without a merger event. Also a kinematically independent investigation of the galactic disc structure based on the star sample from Bensby et al. (2009 in prep) have been performed using the statistical method of cluster analysis. The investigation has been focusing on the possibility to resemble the kinematically selected Galactic populations. Overall the study show diculties in this task, but in a few cases the cluster analysis show some interesting results worth a deeper investigation by future investigators. I also note that when ordering the stars according to the shapes of their respective footprints, using a simple ”sum of squares”, we see a weak age dependence indicating that a low sum of squares implies a young star and a high sum of squares implies an old star. (Less)
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author
Sandell, Johan LU
supervisor
organization
course
ASTM31 20091
year
type
H2 - Master's Degree (Two Years)
subject
publication/series
Lund Observatory Examensarbeten
report number
2009-EXA36
language
English
id
1940240
date added to LUP
2011-05-09 15:05:57
date last changed
2011-05-09 15:05:57
@misc{1940240,
  abstract     = {Detailed abundance analysis of 41 F and G type dwarf stars located in the solar neighborhood are presented. The stellar sample was selected to have kinematics intermediate between the Galactic thin and thick discs. The stars have been observed with the NOT telescope at La Palma, Spain in March 2006 and the ESO 2.2 m telescope at La Silla, Chile between October 1, 2004 and March 31, 2005. Abundance results show good agreement with the previous study by Bensby et al. (2003). For some elements, the inbetween stars represent a fairly smooth transition between the thick disc and the thin disc, which would favor a formation of a thick disc in the Galaxy without a merger event. Also a kinematically independent investigation of the galactic disc structure based on the star sample from Bensby et al. (2009 in prep) have been performed using the statistical method of cluster analysis. The investigation has been focusing on the possibility to resemble the kinematically selected Galactic populations. Overall the study show diculties in this task, but in a few cases the cluster analysis show some interesting results worth a deeper investigation by future investigators. I also note that when ordering the stars according to the shapes of their respective footprints, using a simple ”sum of squares”, we see a weak age dependence indicating that a low sum of squares implies a young star and a high sum of squares implies an old star.},
  author       = {Sandell, Johan},
  language     = {eng},
  note         = {Student Paper},
  series       = {Lund Observatory Examensarbeten},
  title        = {An abundance study of the transition beetween the galactic thick and thin disc},
  year         = {2009},
}