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Line Identification and Temperature Diagnostics of Eta Carina's Sr-Filament

Rhodin, Henrik LU (2013) In Lund Observatory Examensarbeten ASTK01 20122
Lund Observatory
Abstract
This bachelor thesis concerns the NIR spectral region of the Sr-filament, a substructure of the fan located in the equatorial skirt of Eta Carinae. The primary objective was to identify emission features intrinsic to the Sr-filament, and to tabulate these in a line-list spanning the spectral range λλ990 − 2410 nm. A secondary objective was concerned with the use of identified parity-forbidden atomic transitions for temperature diagnostics. The thesis is based on a long-slit NIR spectrum at resolution R approx. 10500, obtained using the ESO X-Shooter instrument at VLT. Centred on the Sr-filament, at a position offset 2.0 arcsec NW of the central object, the target is sampled during the recovery phase of Eta Carinae’s spectroscopic cycle.... (More)
This bachelor thesis concerns the NIR spectral region of the Sr-filament, a substructure of the fan located in the equatorial skirt of Eta Carinae. The primary objective was to identify emission features intrinsic to the Sr-filament, and to tabulate these in a line-list spanning the spectral range λλ990 − 2410 nm. A secondary objective was concerned with the use of identified parity-forbidden atomic transitions for temperature diagnostics. The thesis is based on a long-slit NIR spectrum at resolution R approx. 10500, obtained using the ESO X-Shooter instrument at VLT. Centred on the Sr-filament, at a position offset 2.0 arcsec NW of the central object, the target is sampled during the recovery phase of Eta Carinae’s spectroscopic cycle. 300 emission features spectrally separated the Sr-filament from other sub-structures. Out of these, 144 lines were identified. One Zr II line and two Co II lines are identified, but not confirmed by previous studies. The resulting line-list indicates that the NIR spectrum of the S filament is dominated by CaI, TiII and FeI emission, accounting for 75% of the identified features. [TiII] lines are proposed as candidates for temperature diagnostics due to a span in excitation energy and wavelength. However, a lack of reference atomic transition probabilities prevented numerical calculations being conducted. (Less)
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author
Rhodin, Henrik LU
supervisor
organization
course
ASTK01 20122
year
type
M2 - Bachelor Degree
subject
keywords
η Carinae, Sr-Filament, X-Shooter, Near-Infrared (NIR) Spectra, line list, forbidden lines, Boltzmann Plot, Temperature Diagnostics
publication/series
Lund Observatory Examensarbeten
report number
2013-EXA73
language
English
id
3802854
date added to LUP
2013-05-30 11:31:08
date last changed
2013-05-30 11:31:08
@misc{3802854,
  abstract     = {This bachelor thesis concerns the NIR spectral region of the Sr-filament, a substructure of the fan located in the equatorial skirt of Eta Carinae. The primary objective was to identify emission features intrinsic to the Sr-filament, and to tabulate these in a line-list spanning the spectral range λλ990 − 2410 nm. A secondary objective was concerned with the use of identified parity-forbidden atomic transitions for temperature diagnostics. The thesis is based on a long-slit NIR spectrum at resolution R approx. 10500, obtained using the ESO X-Shooter instrument at VLT. Centred on the Sr-filament, at a position offset 2.0 arcsec NW of the central object, the target is sampled during the recovery phase of Eta Carinae’s spectroscopic cycle. 300 emission features spectrally separated the Sr-filament from other sub-structures. Out of these, 144 lines were identified. One Zr II line and two Co II lines are identified, but not confirmed by previous studies. The resulting line-list indicates that the NIR spectrum of the S filament is dominated by CaI, TiII and FeI emission, accounting for 75% of the identified features. [TiII] lines are proposed as candidates for temperature diagnostics due to a span in excitation energy and wavelength. However, a lack of reference atomic transition probabilities prevented numerical calculations being conducted.},
  author       = {Rhodin, Henrik},
  keyword      = {η Carinae,Sr-Filament,X-Shooter,Near-Infrared (NIR) Spectra,line list,forbidden lines,Boltzmann Plot,Temperature Diagnostics},
  language     = {eng},
  note         = {Student Paper},
  series       = {Lund Observatory Examensarbeten},
  title        = {Line Identification and Temperature Diagnostics of Eta Carina's Sr-Filament},
  year         = {2013},
}