DGalanDieguez

Software

PRISMAS

Pipeline of Radiative Intensity Synthesis for Meshed Atmospheric Surfaces: the intensity grids behind SPAMMS.

Code on GitHub Read the paper

What it does

To compute the spectrum of a distorted star, SPAMMS needs to know how much light each surface element emits towards the observer, at every wavelength and every viewing angle. PRISMAS produces those specific-intensity grids. It wraps the synple spectral-synthesis code (Allende Prieto; SYNSPEC by Hubeny et al. 2021) and turns a folder of model atmospheres into SPAMMS-ready intensities and calibrated Eddington fluxes, for any wavelength range, sampling and microturbulence you choose.

Supported model atmospheres

Grid Physics Typical use --mode
ATLAS9, Castelli & Kurucz (2003) LTE O- to K-type stars KC
ATLAS9, Mészáros et al. (2012) LTE Updated opacities, α and C enhancement KM
TLUSTY OSTAR2002 / BSTAR2006 (Lanz & Hubeny 2003, 2007) Non-LTE Hot stars, Teff ≥ 15 000 K T
Three panels in the log g versus effective temperature plane showing the coverage of the Castelli and Kurucz, Mészáros and TLUSTY grids, with Geneva evolutionary tracks.
Coverage of the three grid families in the log g–Teff plane, over Geneva tracks at solar metallicity (Ekström et al. 2012).

Main features

Full control

Wavelength range, sampling Δλ, microturbulence, μ-grid and line lists.

Reads file names

Teff, log g, [M/H], [α/M] and [C/M] decoded from each grid's native names.

Laptop to HPC

Single model, multiprocessing over a CPU pool, or job arrays on clusters.

Compact output

NumPy arrays packed into .tar.gz, temporary files removed.

Quick start

After installing synple and placing the atomic data and line lists as described in the README, run from the PRISMAS folder:

# one Kurucz-Castelli model, two microturbulences
python3 prismas.py --opt 0 --mode KC --modeldir ./Examples/kurucz_castelli/ \
    --model m0.50t49000g4.5am05k2odfnew.dat \
    --numpydir ./Examples/kurucz_castelli/results/ \
    --wl [3000,5000] --vmic [2,5] --dw 0.01

# a folder of TLUSTY models on 5 cores
python3 prismas.py --opt 1 --mode T --modeldir ./Examples/tlusty/ \
    --numpydir ./Examples/tlusty/results/ --wl [3000,5000] \
    --vmic [1.0,5.0] --dw 0.1 --linelist [gfTLUSTYALL.dat] --ncpus 5

Each model produces the wavelength vector, the specific-intensity and continuum-intensity matrices (101 μ × Nλ, μ from 0 to 1) and the integrated and continuum fluxes, in the layout SPAMMS expects.

Ready-made grids

The full grids from Galán-Diéguez et al. (2026) are already computed:

Wavelength 3000–9000 Å, Δλ = 0.01 Å
Microturbulence 1, 3, 5 and 10 km s−1
Angles 101 values of μ = cos θ
Teff, log g, [M/H] Grid-dependent, see the figure above and the paper

The grids are too large to host publicly. Email me and I will arrange access.

How to cite

The licence is MIT, with one condition: any publication or presentation that uses results from PRISMAS must cite this paper.

Galán-Diéguez et al. (2026)

@ARTICLE{2026arXiv260915331G,
       author = {{Gal{\'a}n-Di{\'e}guez}, D. and {Abdul-Masih}, M. and {Allende Prieto}, C. and {Berlanas}, S.~R. and {Herrero}, A. and {Sana}, H.},
        title = "{SPAMMS: 3D spectroscopic modelling of stellar surfaces. II. Implementation of Kurucz and TLUSTY model atmospheres}",
      journal = {arXiv e-prints},
     keywords = {Solar and Stellar Astrophysics, Earth and Planetary Astrophysics},
         year = 2026,
        month = sep,
          eid = {arXiv:2609.15331},
        pages = {arXiv:2609.15331},
archivePrefix = {arXiv},
       eprint = {2609.15331},
 primaryClass = {astro-ph.SR},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2026arXiv260915331G},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}