Program ATM.FOR (ATMOS)
Model Atmosphere

ATMOS integrates the hydrostatic equation from a given temperature structure and chemical composition. The result is the pressure stratification with continuous opacities and particle concentrations. The result can then be used as input to LINFOR.

There is an alternative version NATM which will not calculate the pressures but reads them from NPTAU.DAT instead. All that NATM does is to compute particle concentrations and continuous opacitities. This version is useful if the temperature structure has been computed with another stellar atmospheres program such as ATLAS9 and should be fed into LINFOR. One has to make sure, however, that the chemical mix is identical in ATMOS and the other program.

Input files:

ABU.DAT
Chemical composition
PTAU.DAT
Temperature structure for monochromatic optical depth.

Output files:

ATM.DAT    (in UNIX ATM [capitals])
The model atmosphere, suitable as input for LINFOR.
screen output    (SYS$OUTPUT/stdout)
Model atmosphere listing, and details about absorbers and ionization equilibria if requested in PTAU.DAT.