Radiative transition rates and collision strengths for the n=3,4,5,6,7,8 configurations of Ca II M. Melendez 1,2 ; M.A. Bautista 3 & N.R. Badnell 4 ITAMP WORKSHOP, August IACS/CUA 2 GSFC/NASA 3 IVIC 4 U. of Strathclyde, UK

Long linear, filamentary ejecta, known as “strings”, are found to move at very high velocity external to the Homunculus. The origin of the strings is a puzzle. Determining if their elemental abundances are similar to other ejecta linked with the brightening events of the 1840’s and the 1890’s, would give insight as to whether these ejecta originated in the outer atmosphere of the erupting star, or possibly much deeper. Motivation (Poster AAS 207 th )

(Å) (Å) 2-D Spectra of the Strontium Filament and a portion of a string

Atomic Data Model Potential (Norcross & Seaton 1976) Dipole core Polarizability  =3.31  =2.25 (Edlen & Risberg 1956)

Atomic Data (a)w/o PI (b)PI 1. R. N. Grosselin. et al (1988). 2. T. Andersen. et al (1970). 3. W. Ansbacher. et al (1985).

Scattering Calculations 4s 2 S1/2 – 3d 2 D 3/2

(a)4s 2 S 1/2 – 3d 2 D 3/2 (b)4s 2 S 1/2 – 3d 2 D 5/2 (c)4s 2 S 1/2 – 4p 2 P 1/2 (d) 4s 2 S 1/2 – 4p 2 P 3/2 PI w/o PI

(a)4s 2 S 1/2 – 3d 2 D 3/2 (b)4s 2 S 1/2 – 3d 2 D 5/2 (c)4s 2 S 1/2 – 4p 2 P 1/2 (d) 4s 2 S 1/2 – 4p 2 P 3/2 PI w/o PI Scattering Calculations

Effective collision strengths 4s-4p 5,000 K 10,000 K 15,000 K 20,000 K w/o PI PI Osterbrock & Wallace (1976), Taylor & Dunn (1973) 2.Burgess A. et. al (1995)

Line Ratios

Conclusions We have computed radiative data, collision strengths and effective collision strengths for transitions among 45 levels from the n=3,4,5,6,7,8 configurations of Ca II. We present an extensive comparison for the polarization contribution to the radiative transition and electron impact excitation rates coefficients, which can lead to contributions of up to 20% in some cases with respect to the "unpolarize" frozen core model. The complete set of data obtained here allows us to build a non-LTE collisional radiative model fo Ca II.

Obs Obs Terms rest restVelFlux Å Å Km s ergs s -1 arcsec [N I] 4 S 0 3/2 - 2 D 0 3/ [N II] 1D2-1S01D2-1S01D2-1S01D2-1S P1-1D23P1-1D23P1-1D23P1-1D HHHH P D [S II] 4 S 3/2 - 2 D 5/ [S II] 4 S 3/2 - 2 D 3/ [Fe II] a 4 F 9/2 - a 2 G 9/ [Ca II] 2 S 1/2 - 2 D 5/ [Ca II] 2 S 1/2 - 2 D 3/ [Ni II] a 2 D 5/2 - a 2 F 7/ [Fe II] a 4 F 9/2 - a 4 P 5/ Line Identification for the String