ATA: A computer code for calculation of model stellar atmospheres

version 033-09

Only files with "Last update" later than 14.7.2018 are being checked with the upgraded version of the code.

The computer code ATA solves the model stellar atmosphere (generally NLTE) for given effective temperature, log g (gravitational acceleration at the stellar surface), and stellar radius. The atmosphere is represented with ND depth points.

Basic methods used in the code:

radiative transfer: accelerated lambda iteration in the linearization step; standard Feautrier scheme for the formal solution, NF frequency points possible
energy equilibrium: at large optical depths differential form (flux correction), at lower optical depths either radiative equilibrium or thermal balance of electrons
hydrostatic equilibrium: standard
statistical equilibrium: NL levels possible, many atomic species; occupation probability formalism; arbitrary reference atom

Basic options:

model atmosphere calculation
NLTE line formation problem
synthetic spectrum
irradiated atmospheres
shells (irradiated from the bottom)

Input files

Debugging options file DEBUG.DAT (obsolete, useless for users; sorry)
Basic input file FT05.DAT
Input of the model atmosphere
Optional input:

Input of the print parameters PRINT.DAT
Input of the incident flux at the upper boundary RTEUBC.DAT
Input of the incident flux at the lower boundary RTELBC.DAT

Output files

Output file of the model atmosphere MODELO.DAT
Basic output file report.lst
Output file of the current maximum relative change iter.lst
Output file of the relative changes relch.lst
Output file of the errors errors.lst
Optional output:

Output of the transitions data: transit.lst
Cross sections: cross.lst

Approximate lambda operator: aprlam.lst
Output of the mean intensities, variable Eddington factors, and Eddington flux: intensit.lst
Output of the angle dependence of the emergent specific intensity: limb.lst
Auxilliary output from the formal solution: formal.lst
Emergent flux for all frequency points, equivalent widths: emflux.lst
Flux for all frequency points at tau_R~2/3: formflux.lst
Flux for all frequency points at the lower boundary: ndflux.lst
Total flux for all depth points: flux.lst
Output of the relative changes of b-factors during the formal solution step: relbf.lst

Convective gradients and other convective variables: convec.lst
Energy (radiative and thermal) balance: enbal.lst
All LTE populations, b-factors, ion populations: popul.lst
All rates (both collisional and radiative) for all depth points: rates.lst
Stability tests: stabil.lst
Detailed output of the LTE populations, ionization fractions, etc.: lte.lst
Extensive output of all relative changes: relal.lst
Output during the depth integration: depint.lst

References:

Kubát J.: 1994, Astron. Astrophys. 287, 179
Kubát J.: 1996, Astron. Astrophys. 305, 255
Kubát J.: 1997, Astron. Astrophys. 326, 277
Kubát J.: 2001, Astron. Astrophys. 366, 210
Kubát J.: 2003, in Stellar Atmosphere Modelling, I. Hubeny, D. Mihalas & K. Werner eds., ASP Conf. Ser. Vol. 288, p. 87
Kubát J.: 2003, in Modelling of Stellar Atmospheres, IAU Symp. 210, N. E. Piskunov, W. W. Weiss & D. F. Gray eds., ASP, A8
Kubát J., 2012, Astrophys. J. Suppl. Ser. 203, 20

Program is available upon request.

Jiří Kubát

Astronomical Institute

251 65 Ondřejov

Czech Republic

e-mail: kubat@sunstel.asu.cas.cz

Last update: 14.7.2018