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

Sammanfattning: 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.