Atomic data for astrophysics: improved collision strengths for Fe VIII

Del Zanna, G. and Badnell, N.R. (2014) Atomic data for astrophysics: improved collision strengths for Fe VIII. Astronomy and Astrophysics, 570. A56. ISSN 0004-6361 (https://doi.org/10.1051/0004-6361/201424508)

[thumbnail of DelZanna-Badnell-AA-2014-Atomic-data-for-astrophysics-improved-collision-strengths]
Preview
 Text. Filename: DelZanna_Badnell_AA_2014_Atomic_data_for_astrophysics_improved_collision_strengths.pdf
Accepted Author Manuscript
Download (273kB)| Preview

Abstract

We describe, and present the results of, a new large-scale R-matrix scattering calculation for the electron collisional excitation of Fe viii. We first discuss the limitations of the previous calculations, in particular concerning some strong EUV lines observed in the solar corona by the Hinode EUV Imaging Spectrometer. We then present a new target which represents an improvement over the previous ones for this particularly complex ion. We developed a new method, based on the use of term energy corrections within the intermediate coupling frame transformation method, to calculate the collision strengths. We compare predicted and observed line intensities using laboratory and solar spectra, finding excellent agreement for all the main soft X-ray and extreme ultraviolet (EUV) transitions, using the present atomic data. In particular, we show that Fe viii EUV lines observed by Hinode EIS can now be used to provide reliable electron temperatures for the solar corona.

  • Item type:Article
    ID code:53860
    Dates:
    Date
    Event
    October 2014
    Published
    16 October 2014
    Published Online
    12 August 2014
    Accepted
    Notes:Reproduced with permission from Astronomy & Astrophysics, © ESO
    Subjects:Science > Astronomy
    Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:24 Jul 2015 09:55
    Last modified:19 Apr 2024 17:22
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/53860
CORE (COnnecting REpositories)