LINES

The program LINES may be used to calculate the equivalent width and the central depth of the lines in a linelist file. This is useful for identifying lines, and also for figuring out the components in a complex blend of lines. But it can also be used for creating a line list file based on the subset of lines in the input linelist file that have equivalent widths greater than a specified value. This can be useful for speeding up a spectral synthesis by eliminating those lines that do not contribute significantly to the spectrum. LINES fully supports isotopes and hyperfine structure, and the full range of line broadening theory in SPECTRUM. The format of the input linelist file is identical to that of SPECTRUM. The inputs are also the same as SPECTRUM (a stellar atmosphere model, the atomic and molecular data file stdatom.dat, and optionally the isotope file isotope.iso). LINES will also prompt the user for the spectral range, and the minimum equivalent width for a line to be included in the output. The default output has the following format:

4190.243   22.1    22.387  0.5531
4190.408   23.1     9.332  0.7928
4190.459  106.0     3.026  0.9610

where the first column is the wavelength, the second the species code, the third the computed equivalent width (units mÅ), the fourth the line depth (with the continuum at 1.0, and assuming infinite resolution with no macroturbulence or rotation). Thus, the core of the third line is only 4% below the continuum. The default (and only mode) is to calculate the equivalent width and line depth for the integrated disk.

The following switches may be used with LINES:

C:

Will cause LINES to print out a file cd.out which contains the ``contribution function'' of the lines in the linelist (note - it is best to invoke this for a linelist that has only a few lines in it). The output file has three columns; the first is the layer number in the stellar atmosphere, beginning with 1 for the top layer, the second is the reference continuous optical depth (at 5000Å) and the third is the contribution function used in calculating the line profile.

i:

Invokes the isotope mode - see § .

s:

Causes LINES to output a linelist file (in exactly the format of the input linelist file) containing those lines that have equivalent widths greater than the minimum equivalent width entered as a prompt to the program. This option is useful for culling linelists of weak lines which do not contribute to the spectrum and would simply slow down a spectral synthesis calculation.

t:

Informs LINES that the stellar atmosphere model is in the ATLAS9/ATLAS12 format - see § .

v:

Verbose mode - the default mode of LINES is to be silent - i.e. to print nothing to the screen beyond a few initial messages. This switch causes LINES to print to screen everything it prints out to the default output file.