Ne I 
Ne II
Ne III 
Ne IV
This issue of Comms
ULO contains text and graphics files referenced in the paper on Neon
radiative accelerations. We discuss the details and results of the
acceleration calculations with and without Non-LTE in the main paper.
Text files for Ne I calculations: naming conventions
file.5 -tlusty model input file
file.7 -tlusty model computed with file.5 data
file.acc -radiative acceleration for the model file.7 for each ion
and abundance
file.acc.sum -radiative accelerations weighted by ioniz. fractions
and diffusion coefficients for each abundance
file.acc.sum2 -radiative accelerations weighted by ioniz. fractions
only for each abundance
file.acc.inlte0 -radiative acceleration on NeI in LTE
file.acc.inlte-3 -rad.accel. on NeI in approx. NLTE
file.acc.inlte1 -rad.accel. on NeI in full NLTE
file.lin -bound-bound transitions selected and relevant for file.7
model
tlusty* -model of the atom
n12nl.acc.redour2.sum -with our redistribution model
n12nl.acc.redglam.sum -with Gonzales et al. redist. model but our formulae
kresli.gnu -gnuplot source file to plot the radiative accelerations
computed for a particular model.
Graphics files for Ne I calculations
The reader can produce a graphic of accelerations of Ne from our data
using a simple gnuplot routine based
on files in the directory ne
and the input file kresli.gnu.
Using any of the files with acc in the name, copy the file to the input
name accel.tot and run gnuplot--just do:
cp file.acc accel.tot
gnuplot kresli.gnu
(output for Ne I through IV is also in *.eps files).
The diagrams of Ne I to Ne IV accelerations are in the files *.eps; thumbnail links are given below. We have also provided .gif versions of these plots for those who can't view .eps files in a browser.
Encapsulated Postscript Files (.eps):
Ne I
Ne II
Ne III
Ne IV
Transparent GIF (.gif) images:
Ne I 
Ne II
Ne III 
Ne IV
To look at any of the text files, click on the link below to the directory of neon text and .eps files, ne/
To save any of the files as a download, with a Web browser either use the `File--save as' pulldown menu after opening the file, or <shift>left-click on the underlined link and you should be able to save the whole file without viewing it. Files with numbers in their names like 1235 refer to the Teff and log g of the model, e.g., these figures refer to a 12000 K, log g 3.5 model.
The tlusty files are input files for the Ne I and Ne II models used for the NLTE calculations in the main paper; some of the data were generated using the MODION program of Varosi et al (1995). Tlusty (Hubeny 1988; Hubeny and Lanz 1992, 1995) is a general NLTE stellar atmospheres program developed and maintained by Hubeny et al. (1995) as is SYNSPEC, for synthesis of spectra.
The entire directory (with .eps graphs only) is available for download as a 460K gzipped tar file: ne.tar.gz
The Partition Functions
The partition function routines from the UCLSYN spectrum synthesis codes were prepared by B. Smalley and M. Dworetsky from various sources, and include for some elements a specific method of adding on the higher hydrogenic levels near the ionization limit by approximating the sum as an integral, following the methods of Kurucz (1970). The statistical weight of the summed levels of principal quantum number n is Gn2; in the case of hydrogen G=2; for Cr I, G = 12. An easy way to evaluate G is to look at the statistical weight of the ground state of the next higher ion (the limit of the series for the ionization potential). (We leave it to readers to prove this for themselves.) For example, for Cr I --> Cr II, the ground state of Cr II is 6S21/2 and G = 2 x multiplicity x (2L +1), where multiplicity = 6, L = 0 (for S), and 2 is the number of possible electron spin states. Therefore, G = 12. For Cr II --> Cr III, the ground state is 5D0 and G (Cr II) = 50. (In atomic energy level notation, L= 0 for S, 1 for P, 2 for D, 3 for F, etc). The subroutine BRAKET implements this integration as a series approximation and uses G in the evaluation (eq. 4.40 in Kurucz 1970).
The partition functions u(T) are tabulated by values of ln (u) with an equal step size in T governed by the ionization potential. Interpolation in the table is linear, and extrapolation past the highest value is linear. Anyone interested in the details can read the Fortran 77 code given here as pfdwor.f . To run this code under Linux, for example, simply download the code and compile it with
g77 pfdwor.f -o pfdwor and execute pfdwor. The output file will
be named pfdwor.out and will list the computed partition functions for
92 elements. These are the same as the partition functions used in
the MNRAS paper.
The Authors
J. Budaj (University of London Observatory, University College London and Astronomical Institute of the Slovak Academy of Sciences, 05960 Tatranska Lomnica, Slovak Republic)
M. M. Dworetsky (University of London Observatory, University College London)
B. Smalley (Department
of Physics, Keele University, Keele, Staffordshire, ST5 5BG)
Acknowledgements
J. Budaj gratefully acknowledges the support of a Royal Society/NATO Fellowship (98B) and partial support by the VEGA grant No. 7107 from the Slovak Academy of Sciences.
References
Hubeny I., 1988, Comput. Phys. Comm., 52, 103
Hubeny I., Lanz T., 1992, Astron. & Astrophys., 262, 501
Hubeny I., Lanz T., 1995, Astrophys. J., 439, 875
Hubeny I., Lanz T., Jeffery, C.S., 1995, Tlusty & Synspec-A User's
Guide http://tlusty.gsfc.nasa.gov/
Kurucz, R. L., 1970, ATLAS: A Computer Program for Calculating Model
Stellar Atmospheres (Smithsonian Astrophysical Observatory Special Report
309), pp. 63-65.
Varosi F., Lanz T., Dekoter A., Hubeny I. & Heap S., 1995, MODION
(NASA Goddard SFC) ftp://idlastro.gsfc.nasa.gov/pub/contrib/varosi/modion/