Abstract
Eta Carinae is a super-massive, super-luminous star. It is surrounded by a bipolar nebula, the "Homunculus", and several blobs of ejected gas which are the source of a complex emission-line spectrum. This thesis presents results from spectroscopic investigations of the star and its surroundings, performed with the Space Telescope Imaging Spectrograph (STIS) and the Goddard High Resolution Spectrograph (GHRS) onboard the Hubble Space Telescope (HST). The age of the equatorial disk in the Homunculus has been studied by measurements of radial velocities of emission lines. Fluorescence processes in Fe II, Fe III, and Cr II are discussed, and the discovery of an ejected filament producing Sr II and [Sr II] emission is reported. Also, a list of 2000 emission line identifications is presented and discussed.
The chemically peculiar star Chi Lupi was the target of the "Pathfinder Project", a mapping of the UV spectrum of the star using the GHRS. An investigation of the abundance and isotopic composition of boron in Chi Lupi is presented.
The launch of space telescopes has put greater demands on the quality of atomic data needed for the analyses of the observed spectra. This thesis presents laboratory measurements of wavelengths and transitions isotope shifts in the B~II spectrum.
The chemically peculiar star Chi Lupi was the target of the "Pathfinder Project", a mapping of the UV spectrum of the star using the GHRS. An investigation of the abundance and isotopic composition of boron in Chi Lupi is presented.
The launch of space telescopes has put greater demands on the quality of atomic data needed for the analyses of the observed spectra. This thesis presents laboratory measurements of wavelengths and transitions isotope shifts in the B~II spectrum.
Original language | English |
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Qualification | Doctor |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 2001 Mar 9 |
Publisher | |
ISBN (Print) | 91-7874-112-2 |
Publication status | Published - 2001 |
Bibliographical note
Defence detailsDate: 2001-03-09
Time: 10:15
Place: Lecture Hall B at the Department of Physics
External reviewer(s)
Name: Pagel, Bernard
Title: Professor
Affiliation: [unknown]
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Article: T. Zethson, S. Johansson, K. Davidson, R.M. Humphreys, K. Ishibashi, and D. Ebbets, "Strange velocities in the equatorial ejecta of Eta Carinae", Astronomy & Astrophysics, Vol. 344, p.211, 1998
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Article: S. Johansson, T. Zethson, H. Hartman, J.O. Ekberg, K. Ishibashi, K. Davidson, and T.R. Gull, "New forbidden and fluorescent Fe III lines identified in HST spectra of Eta Carinae", Astronomy & Astrophysics, Vol. 361, p.977, 2000
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Article: T. Zethson, T.R. Gull, H. Hartman, S. Johansson, K. Davidson, and K. Ishibashi, "Sr II and [Sr II] emission in the ejecta of Eta Carinae", submitted to The Astronomical Journal
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Article: T. Zethson, H. Hartman, S. Johansson, T.R. Gull, K. Ishibashi, and K. Davidson, "Cr II fluorescence in Eta Carinae due to Hydrogen Lyman-alpha pumping", to appear in the proceedings (ASP Conf. Series) of the meeting: Eta Carinae and other mysterious stars -- the hidden opportunities of emission line spectroscopy, August 24-26, 2000, Hven, Sweden
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Article: U. Litzen, T. Zethson, P. Jönsson, J. Kasten, R. Kling, and F. Launay, "Precision measurements and calculations in the B II spectrum: Wavelengths, isotope shifts, and oscillator strengths", Physical Review A, Vol. 57, p.2477, 1998
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Article: T. Zethson, S. Johansson, G.M. Wahlgren, and D. Leckrone, "High-resolution observation of B II 1362 Å in Chi Lupi", The Scientific impact of the Goddard High Resolution Spectrograph, eds. J.C. Brandt, T.B. Ake, and C.C. Petersen, ASP Conf. Ser. Vol. 143, p.339, 1998
Subject classification (UKÄ)
- Subatomic Physics
Free keywords
- magnetic and optical properties
- supraconductors
- electrical
- Rymdteknik
- kosmisk kemi
- Condensed matter:electronic structure
- rymdvetenskap
- Astronomi
- cosmic chemistry
- space research
- Astronomy
- boron
- isotope shifts
- Chi Lupi
- fluorescence
- element abundances
- emission lines
- GHRS
- strontium
- STIS
- Eta Carinae
- spectroscopy
- Hubble Space Telescope
- supraledare
- magnetiska och optiska)
- magnetisk resonans
- Space technology
- spektroskopi
- relaxation
- magnetic resonance
- egenskaper (elektriska)
- Kondenserade materiens egenskaper:elektronstruktur