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3. Description of tables

 

The tables are available only electronically from the Centre de Données astronomique de Strasbourg (CDS)gif. They cover the Lyman, Balmer, Paschen, and Brackett series up to n=22 for a slightly extended grid of T and tex2html_wrap_inline6453 than the 1973 tables. The tables contain the logarithm of the normalized Stark profile tex2html_wrap_inline6455 with
equation267
where the distance tex2html_wrap_inline6457 from the line center is in Ångströms and the normal field strength tex2html_wrap_inline6459 (in esu) is given as
equation269
Normalization was such that
equation274
Unlike the original tables the grid is rectangular for easy interpolation and covers the range tex2html_wrap_inline6461K; tex2html_wrap_inline6463cmtex2html_wrap_inline6465; and tex2html_wrap_inline6467 (tex2html_wrap_inline6469 for some higher lines) tex2html_wrap_inline6471, all in the same steps as the original tables: tex2html_wrap_inline6473, tex2html_wrap_inline6475, tex2html_wrap_inline6477. Note that the scaling of the Lyman lines results in a slightly different tex2html_wrap_inline6479 for the higher lines.

The code was not able to compute profiles for the higher lines of a series for high tex2html_wrap_inline6481 and low T. This simply reflects the fact that the upper level does no longer exist for such high densities. However, for practical applications it is much easier to deal with a rectangular table instead of having the number of points vary with tex2html_wrap_inline6485 and T. To ease the use of the tables we simply copied the last correctly produced profile to the lower temperature and indicate this fact with a flag (see Table 3 (click here)). This allows easy interpolation and reading of the table with a single Fortran read statement. But we caution the reader that such profiles are not physically meaningful.

The pure Stark profiles and the broadened profiles are given in separate files. The file layout is given in Table 1 (click here) and a minimal Fortran illustration for how to read it is given in Table 2 (click here).

Note added in proofs: After the paper had been accepted for publication it was realized that the unbroadened profiles were computed not close enough to the line center. As a result, the cores and small parts of the wings of the Doppler-broadened profiles were too shallow. This was most serious for tex2html_wrap_inline6489. We have therefore extended the affected profiles further down towards the line center. In correction to Sect. 3, tex2html_wrap_inline6491, tex2html_wrap_inline6493, and tex2html_wrap_inline6495 are all computed down to tex2html_wrap_inline6497. This removes the remaining differences between our tables and VCS'. The Doppler-broadened profiles are tabulated only with as many points as are neccessary to recover the line center. Consequently, the smallest tabulated tex2html_wrap_inline6499 varies from line to line; the first point is also valid for all smaller values of tex2html_wrap_inline6501. A table with tex2html_wrap_inline6503 for all lines can be found on the ftp servers. The information is of course contained in the actual profile tables as defined in Table 1 (click here).

  Table 1: File layout. The ``goodness flag" is defined as follows: 0: profile ok; -1: copied from next higher T, -2: copied from 2nd next higher T etc.; -10: copied from next lower tex2html_wrap_inline6515, -20: copied from 2nd next lower tex2html_wrap_inline6519 etc; -23: copied from 2nd next lower tex2html_wrap_inline6523, then copied down three T steps

  Table 2: Fortran illustration for reading table

  Table 3: Overview of explicitly computed tables and goodness flag. The higher profiles not displayed here are scaled Lyman profiles (see text). Shown is the absolute value of the goodness flag as defined in Table 1 (click here). The abbreviated temperatures stand for 2500, 5000, 10000, 20000, 40000, 80000, 160000 K, respectively

Table 3 (continued):

Acknowledgements

I thank Tony Lynas-Gray for bringing to my attention the existence of the code and for having it installed and put at my disposal. I am also thankful to Dieter Engelhardt, Ralf Napiwotzki, and Thomas Rauch for useful discussions. The computations were carried out in parallel on several Starlink-provided SparcStations at the Institute of Astronomy, Cambridge. Financial support from the Leverhulme foundation under grant F627C is thankfully acknowledged.


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