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The FERRUM project: experimentally determined metastable lifetimes and transition probabilities for forbidden [Ti II] lines observed in eta Carinae

Hartman, Henrik LU ; Schef, P; Lundin, P; Ellmann, A; Johansson, Sveneric LU ; Lundberg, Hans LU ; Mannervik, S; Norlin, L O; Rostohar, D and Royen, P (2005) In Monthly Notices of the Royal Astronomical Society 361(1). p.206-210
Abstract
In the spectrum of an emission-line region ejected from the massive star Eta Carinae, called the strontium filament (SrF), forbidden lines from many elements, in particular [Sr II] and [Ti II], are observed. These lines are strong in this specific region and valuable for plasma diagnostics. Forbidden lines are not easily produced in laboratory light sources and the atomic parameters for these lines can thus not be measured in a straightforward way. We use a combination of laboratory and astrophysical measurements to determine transition probabilities for the [Ti II] lines. Lifetimes for metastable levels in Ti II are measured using a laser probing technique on a stored ion beam at CRYRING, MSL, Stockholm. Branching fractions from some of... (More)
In the spectrum of an emission-line region ejected from the massive star Eta Carinae, called the strontium filament (SrF), forbidden lines from many elements, in particular [Sr II] and [Ti II], are observed. These lines are strong in this specific region and valuable for plasma diagnostics. Forbidden lines are not easily produced in laboratory light sources and the atomic parameters for these lines can thus not be measured in a straightforward way. We use a combination of laboratory and astrophysical measurements to determine transition probabilities for the [Ti II] lines. Lifetimes for metastable levels in Ti II are measured using a laser probing technique on a stored ion beam at CRYRING, MSL, Stockholm. Branching fractions from some of these levels are derived from Hubble Space Telescope/STIS spectra of the SrF. The astrophysical branching fractions are combined with the experimental lifetimes to determine absolute transition probabilities. We report lifetimes for the Ti II levels b(4)P(3/2), b(2)P(1/2), c(2)D(3/2) and c(2)D(5/2), in the range 0.29-17 s, and transition probabilities for eight parity-forbidden lines from the levels c(2)D(3/2) and c(2)D(5/2), along with uncertainty estimates. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
atomic data, stars : individual : Eta Carinae
in
Monthly Notices of the Royal Astronomical Society
volume
361
issue
1
pages
206 - 210
publisher
Wiley-Blackwell
external identifiers
  • wos:000230304300014
  • scopus:22944442598
ISSN
1365-2966
DOI
10.1111/j.1365-2966.2005.09157.x
language
English
LU publication?
yes
id
f6715683-0a47-44ae-b545-cfbcb046d2f2 (old id 233386)
date added to LUP
2007-09-28 08:33:00
date last changed
2017-09-17 05:15:30
@article{f6715683-0a47-44ae-b545-cfbcb046d2f2,
  abstract     = {In the spectrum of an emission-line region ejected from the massive star Eta Carinae, called the strontium filament (SrF), forbidden lines from many elements, in particular [Sr II] and [Ti II], are observed. These lines are strong in this specific region and valuable for plasma diagnostics. Forbidden lines are not easily produced in laboratory light sources and the atomic parameters for these lines can thus not be measured in a straightforward way. We use a combination of laboratory and astrophysical measurements to determine transition probabilities for the [Ti II] lines. Lifetimes for metastable levels in Ti II are measured using a laser probing technique on a stored ion beam at CRYRING, MSL, Stockholm. Branching fractions from some of these levels are derived from Hubble Space Telescope/STIS spectra of the SrF. The astrophysical branching fractions are combined with the experimental lifetimes to determine absolute transition probabilities. We report lifetimes for the Ti II levels b(4)P(3/2), b(2)P(1/2), c(2)D(3/2) and c(2)D(5/2), in the range 0.29-17 s, and transition probabilities for eight parity-forbidden lines from the levels c(2)D(3/2) and c(2)D(5/2), along with uncertainty estimates.},
  author       = {Hartman, Henrik and Schef, P and Lundin, P and Ellmann, A and Johansson, Sveneric and Lundberg, Hans and Mannervik, S and Norlin, L O and Rostohar, D and Royen, P},
  issn         = {1365-2966},
  keyword      = {atomic data,stars : individual : Eta Carinae},
  language     = {eng},
  number       = {1},
  pages        = {206--210},
  publisher    = {Wiley-Blackwell},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {The FERRUM project: experimentally determined metastable lifetimes and transition probabilities for forbidden [Ti II] lines observed in eta Carinae},
  url          = {http://dx.doi.org/10.1111/j.1365-2966.2005.09157.x},
  volume       = {361},
  year         = {2005},
}