open access publication

Article, 2023

Non-LTE radiative transfer with Turbospectrum

In: Astronomy & Astrophysics, ISSN 1432-0746, 0004-6361, Volume 669, Page a43, 10.1051/0004-6361/202243673

Contributors (7)

Gerber, Jeffrey M (0000-0001-9583-0004) (Corresponding author) [1] Magg, Ekaterina [1] Plez, Bertrand (0000-0002-0398-4434) [2] Bergemann, Maria (0000-0002-9908-5571) [1] [3] Heiter, Ulrike (0000-0001-6825-1066) [4] Olander, Terese [4] Hoppe, Richard (0000-0002-8451-6260) [1]


  1. [1] Max Planck Institute for Astronomy
  2. [NORA names: Germany; Europe, EU; OECD]
  3. [2] Laboratoire Univers et Particules de Montpellier
  4. [NORA names: France; Europe, EU; OECD]
  5. [3] University of Copenhagen
  6. [NORA names: KU University of Copenhagen; University; Denmark; Europe, EU; Nordic; OECD]
  7. [4] Uppsala University
  8. [NORA names: Sweden; Europe, EU; Nordic; OECD]


Physically realistic models of stellar spectra are needed in a variety of astronomical studies, from the analysis of fundamental stellar parameters, to studies of exoplanets and stellar populations in galaxies. Here we present a new version of the widely used radiative transfer code Turbospectrum, which we update so that it is able to perform spectrum synthesis for lines of multiple chemical elements in non-local thermodynamic equilibrium (NLTE). We use the code in the analysis of metallicites and abundances of the Gaia FGK benchmark stars, using 1D MARCS atmospheric models and the averages of 3D radiation-hydrodynamics simulations of stellar surface convection. We show that the new more physically realistic models offer a better description of the observed data, and we make the program and the associated microphysics data publicly available, including grids of NLTE departure coefficients for H, O, Na, Mg, Si, Ca, Ti, Mn, Fe, Co, Ni, Sr, and Ba.


Ba, CO, Ca, Fe, Gaia FGK benchmark stars, LTE radiative transfer, Mg, Mn, Na, Ni, Si, Sr, Ti, Turbospectrum, abundance, analysis, astronomical studies, atmospheric model, average, benchmark stars, chemical elements, code, coefficient, convection, data, departure coefficients, description, elements, equilibrium, exoplanets, fundamental stellar parameters, galaxies, good description, grid, lines, metallicites, model, multiple chemical elements, new version, non-local thermodynamic equilibrium, observed data, parameters, population, program, radiation hydrodynamics simulations, radiative transfer, realistic model, simulations, spectra, spectrum synthesis, stars, stellar parameters, stellar populations, stellar spectra, stellar surface convection, study, study of exoplanets, surface convection, synthesis, thermodynamic equilibrium, transfer, variety, version


  • Office of the Director
  • European Research Council
  • Deutsche Forschungsgemeinschaft
  • Swedish National Space Board