The ".opa" files with continuous opacities

The "opa" format files are model files constructed for the calculation of synthetic spectra from MARCS models with line-data files compiled by the user. Here is a FORTRAN subroutine to read a continuous-opacity file and store it into arrays.

    MRXF   56   5000.00

    1) label. 2) no of depth points in the model. 3) wavelength (Å) for the standard opacity

    1071

    the number of wavelengths for which continuous scattering and absorption is given 

          912.82     924.44     943.69     967.98     994.02    1018.31    1037.56    1049.18    1055.17    1063.83

    listing of these wavelengths (Å), these are selected to take care of opacity edges so that linear interpolation

    should work fine.

    (104 lines skipped)

      1604691.00 1623076.50 1650000.00 1676923.50 1695309.00 1704691.00 1723076.50 1750000.00 1776923.50 1795309.00

      1804691.00 1823076.50 1850000.00 1876923.50 1895309.00 1904713.50 1923187.25 1950240.00 1977292.75 1995766.50

      2000482.0

      1.0000E+00 7.6855E-04 2.7584E+03 2.5009E-06 2.6666E+02 1.5165E-09 2.0000E+00 4.4348E-04

    the last line is the start of the listing of the first (outermost) depth point: 1) geometry factor, 1.0 for plane-parallel

    models and ≤ 1.0 for spherical models. 2) optical depth at the standard wavelength (5000 Å). 3) temperature (K).

    4) electron pressure (cgs). 5) gas pressure (cgs). 6) density (cgs). 7) microturbulence parameter (km/s).

    8) total opacity (absorption+scattering at the standard wavelength 5000 Å)

      5.7495E+02 3.7985E+03 5.4600E+02 3.7985E+03 5.0825E+02 3.7985E+03

    1071 pairs of numbers for the wavelengths listed at the top.

    1) true absorption (at 912.82 Å) divided by the total opacity, col 8 in the line above.

    2) scattering (at 912.82 Å) divided by the total opacity, col 8 in the line above.

    3) true absorption (at 924.44 Å) divided by the total opacity, col 8 in the line above.

    4) scattering (at 924.44 Å) divided by the total opacity, col 8 in the line above.

    5) true absorption (at 943.69 Å) divided by the total opacity, col 8 in the line above.

    6) scattering (at 943.69 Å) divided by the total opacity, col 8 in the line above.

      4.7818E+02 3.7985E+03 4.6610E+02 3.7985E+03 4.6835E+02 3.7985E+03

      4.7388E+02 3.5182E+03 4.7697E+02 3.2611E+03 4.7831E+02 3.1372E+03

      4.7975E+02 2.9680E+03 4.8022E+02 2.9010E+03 4.8038E+02 2.8798E+03

      4.8066E+02 2.8420E+03 4.8154E+02 2.7324E+03 3.8570E+02 2.5968E+03

    (350 lines skipped)

    then the end for depth point 1 and the beginning of number 2:

      9.6057E-01 6.4986E-06 9.6343E-01 6.4985E-06 9.7031E-01 6.4985E-06

      9.8016E-01 6.4985E-06 9.8847E-01 6.4985E-06 9.9079E-01 6.4985E-06

      9.9953E-01 1.1989E-03 2.7970E+03 3.5641E-06 3.6230E+02 2.0343E-09 2.0000E+00 4.4354E-04

      6.8965E+02 3.7922E+03 6.4985E+02 3.7922E+03 5.9623E+02 3.7922E+03

      5.4946E+02 3.7922E+03 5.2293E+02 3.7922E+03 5.1429E+02 3.7922E+03

      5.1252E+02 3.5124E+03 5.1166E+02 3.2557E+03 5.1108E+02 3.1321E+03

    (19683 lines skipped)

      6.0292E+03 7.9467E-05 5.9957E+03 7.9467E-05 5.9868E+03 7.9467E-05

      5.9865E+03 7.9467E-05 5.9941E+03 7.9467E-05 6.0240E+03 7.9467E-05

      6.0746E+03 7.9467E-05 6.1202E+03 7.9467E-05 6.1331E+03 7.9467E-05

      12.000  10.930  -2.900  -2.600  -1.210   4.410   3.800   5.060   0.480   4.480

       2.330   3.980   2.470   3.950   1.450   3.730   1.280   2.800   1.120   2.760

      -0.830   1.420   0.000   1.670   1.390   3.500   0.920   2.250   0.210   0.600

      -1.120  -0.590  -1.630  -0.590  -1.370  -0.690  -1.400  -1.030  -1.760  -1.400

      -2.580  -2.080 -99.000  -2.160  -2.880  -2.310  -2.760  -2.230  -3.180  -2.000

      -3.000  -1.760  -2.490  -1.830  -2.870  -1.870  -2.830  -2.420  -3.290  -2.500

     -99.000  -2.990  -3.490  -2.880  -3.650  -2.860  -3.490  -3.070  -3.850  -2.920

      -3.940  -3.120  -4.130  -3.310  -3.720  -2.550  -2.650  -2.200  -3.150  -2.870

      -2.050  -3.290 -99.000 -99.000 -99.000 -99.000 -99.000 -99.000  -3.910

     -99.000  -4.500

    the final 10 lines specify the chemical composition of the model, the total number abundances

    of the 92 first elements in the periodic table on a logarithmic scale where hydrogen=12.0