colors module controls

colors module controls#

Colors User Parameters#

use_colors#

Set to .true. to enable bolometric and synthetic photometry output.

instrument#

Path to the filter instrument directory (structured as facility/instrument). The directory must contain an index file named after the instrument and one .dat transmission curve per filter. Each filter becomes a history column.

stellar_atm#

Path to the directory containing the stellar atmosphere lookup table and spectra used by the colors module. The default uses the Kurucz2003all ATLAS9 atmosphere grid shipped with MESA. Must contain: lookup_table.csv, SED files, and optionally flux_cube.bin. Castelli & Kurucz 2003 – https://arxiv.org/abs/astro-ph/0405087 SVO model – https://svo2.cab.inta-csic.es/theory/newov2/index.php?models=Kurucz2003all

vega_sed#

Path to the Vega reference SED file. Required when mag_system = ‘Vega’. Used to compute photometric zero-points for all filters.

distance#

Distance to the star in cm. Determines whether output magnitudes are absolute (default: 10 pc = 3.0857e19 cm) or apparent (set to source distance).

make_csv#

If .true., exports the full SED as a CSV file at every profile interval. Files are written to colors_results_directory.

colors_results_directory#

Directory where CSV outputs (make_csv, sed_per_model) are saved.

mag_system#

Photometric zero-point system. Options: ‘Vega’, ‘AB’, ‘ST’.

Vega : zero-point set so Vega has magnitude 0 in all bands. AB : zero-point based on flat f_nu = 3631 Jy. ST : zero-point based on flat f_lambda per unit wavelength.

sed_per_model#

Requires make_csv = .true. If .true., each SED output file is suffixed with the model number, preserving the full SED history rather than overwriting. WARNING: can produce very large numbers of files. Ensure adequate storage.

If use_colors is true, the colors module computes bolometric and synthetic magnitudes by interpolating stellar atmosphere model grids and convolving with photometric filter transmission curves. Output is appended to history.data.

use_colors = .false.
instrument = 'data/colors_data/filters/Generic/Johnson'
stellar_atm = 'data/colors_data/stellar_models/Kurucz2003all/'
vega_sed = 'data/colors_data/stellar_models/vega_flam.csv'
distance = 3.0857d19     ! 10 parsecs in cm -> Absolute Magnitudes
make_csv = .false.
colors_results_directory = 'SED'
mag_system = 'Vega'
sed_per_model = .false.

z_over_x_ref#

z_over_x_ref is the reference metal-to-hydrogen ratio used to map the photospheric composition onto the atmosphere-table metallicity axis: [Fe/H] = log10((Z/X)/z_over_x_ref).

The default matches the GS98 solar mixture used by the default Kurucz2003all ATLAS9 atmosphere grid and equals 0.0169/(1 - 0.0169 - 0.2485) = 2.30057173972d-2.

If the photospheric metallicity, expressed as Z/X, falls outside the metallicity range available in the tabulated atmosphere lookup table, then MESA uses the nearest metallicity in the table for the atmosphere interpolation. If the photospheric hydrogen mass fraction or metal mass fraction is not positive, then MESA cannot form log10((Z/X)/z_over_x_ref). In that case the module still returns colors and SEDs, but it does so by using the lowest metallicity in the table. This is a fallback safeguard and not a dedicated treatment for H-free atmospheres.

For the shipped Kurucz2003all table in this checkout, the metallicity range is [Fe/H] = -2.5 to [Fe/H] = 4.0. With the default z_over_x_ref, the lower edge corresponds to Z/X ~ 7.275d-5.

z_over_x_ref = 2.30057173972d-2

Extra inlist controls#

One can split a colors inlist into pieces using the following parameters. It works recursively, so the extras can read extras too.

read_extra_colors_inlist(1..5)#

extra_colors_inlist_name(1..5)#

If read_extra_colors_inlist(i) is true, then read &colors from the file extra_colors_inlist_name(i).

read_extra_colors_inlist(:) = .false.
extra_colors_inlist_name(:) = 'undefined'
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