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Summary of the IRON and OPACITY Projects

Published online by Cambridge University Press:  30 March 2016

Keith A. Berrington
Keith A. Berrington*
Affiliation:
Department of Applied Mathematics and Theoretical Physics, Queen’s University, Belfast BT7 1NN, U.K.

Extract

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Considerable effort has been made recently by international collaborations, exploiting advances in atomic physics and in supercomputing, to compute complete sets of accurate data for astrophysically important processes; in particular, the Opacity Project and the IRON Project.

The Opacity Project computed atomic data for opacity calculations

  1. • for H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe.

  2. • energies of terms having effective quantum numbers v≤10 and total angular momentum L≤3 or 4, all spin and parity combinations;

  3. • gƒ-values for all dipole transitions between these bound terms;

  4. • total cross sections for photoionizaion from all calculated bound terms, tabulated on a grid of photon energies suitable to describe the resonance structure in sufficient detail to calculate reliable opacities;

  5. • line broadening parameters.

28 key research papers arising from the Project, together with calculated energies and oscillator strengths for light ions, are reprinted in ‘The Opacity Project Volume 1’ (Opacity Project Team, 1994, IOP Publ. ISBN 0 7503 0288 7). All data are available from TOPbase, an on-line database at the CDS (Cunto et al. 1993, A&A 275, L5).

The IRON Project aims to systematically compute electron excitation cross sections for the iron group of elements. Particular attention is given to requirements for the interpretation of data from specific space observations.

In the first stage of the Project excitation cross sections have been computed for fine-structure transitions in the ground configuration of all ions of astrophysical interest. These data are essential for the interpretation of IR lines to be observed by ISO, as well as for coronal spectra.

Type
II. Joint Discussions
Information
Highlights of Astronomy , Volume 10: Highlights of Astronomy. As presented at the XXIInd General Assembly of the IAU, 1994 , 1995 , pp. 571 - 572
Copyright
Copyright © Kluwer 1995

References

I. Goals and methods. Hummer, D.G., Berrington, K.A., Eissner, W., Anil K., Pradhan, Saraph, H.E., Tully, J.A., 1993, A&A 279, 298–309 Google Scholar
II. Effective collision strengths for infrared transitions in carbon-like ions. Lennon, D.J., Burke, V.M., 1994, A&AS 103, 273–277 Google Scholar
III. Rate coefficients for electron impact excitation of Boron-like ions: Na VI, Mg VIII, Al IX, Si X, S XII, Ar XIV, Ca XVI and Fe XXII. Hong Lin, Zhang,Mark, Graziani, Anil K., Pradhan, 1994, A&A 283, 319–330 Google Scholar
IV. Electron excitation of the 2P°(3/2)-2P°(1/2) fine structure transition in fluorine-like ions. Saraph, H.E. and Tully, J.A., 1994, A&AS (in press)Google Scholar
V. Effective collision strengths for transitions in the ground configuration of oxygen-like ions. Butler, K., Zeippen, C.J., 1994, A&AS (in press)Google Scholar
VI. Collision Strengths and Rate Coefficients for Fe II. Hong Lin, Zhang and Anil K., Pradhan, 1994, A&AS (in press)Google Scholar
VII. Radiative Transition Probabilities for Fe II. Nahar, S.N., 1994, A&ASGoogle Scholar
VIII. Electron excitation of the 3d4 5DJ ground state fine structure transition in the Ti-like ions V II, Cr III, Mn IV, Fe v, Co VI and Ni VII. Berrington, K.A., 1994, A&AS (in press)Google Scholar
IX. Electron excitation of the 2P°3/2 -1/2 fine structure transitions in chlorine-like ions from Ar II to Ni XII. Pelan, J.C. and Berrington, K.A., 1994, A&AS (in press)Google Scholar
X. Effective collision strengths for infrared transitions in silicon- and sulphur-like ions. Galavis, M.E., Mendoza, C. and C.J., Zeippen, 1994, A&ASGoogle Scholar
XI. The 2P°1/2.-3/3 fine structure lines of Ar VI, K VII and Ca VIII. Saraph, H.E. and Storey, P.J., 1994, A&AS (submitted)Google Scholar