## Overview

The grids and source code are available here.

The "MARCS" grid uses 1D MARCS models with standard alpha-enhancement at low metallicity. Microturbulence is set to 1 km/s for `logg >= 4`

and 2 km/s for `logg < 4`

, i.e. dwarfs and giants.

The "mean3D" grid uses temporally and spatially averaged <3D> STAGGER models with standard alpha-enhancement at low metallicity. Microturbulence here is set to 1 km/s for `logg >= 3.5`

and 2 km/s for `logg < 3.5`

.

Please cite the reference paper if you use these routines or grids: Nordlander, T., & Lind, K. 2017, A&A, 607, A75. Additional models and detailed line profiles or fits can be provided on request.

The NLTE and LTE grid structures contain the following fields:

```
nabund, nteff, nlogg, nfeh - long: number of elements for each parameter
nlines - long: number of spectral lines in synthetic grid
nlevels - long: long, number of levels in the atomic model
abund - fltarr(nabund): [X/Fe] parameters (solar abundance = 6.43)
teff - fltarr(nteff): Teff parameters [K]
logg - fltarr(nlogg): log(g) parameters [cgs]
feh - fltarr(nfeh): [Fe/H] parameters
logEW - fltarr(nabund,nteff,nlogg,nfeh,nlines): Grids of equivalent widths,
stored as log(EW / pm). These are interpolated to compute NLTE corrections.
wavelength - fltarr(nlines): air wavelength in units of Angstrom
loggf - fltarr(nlines): line oscillator strengths
GA, GQ, GW - fltarr(nlines): Radiative, Starck and Hydrogen collision broadening
of spectral lines. When GW = 1.5, the Unsold approximation is used.
If GW>20, then BPO broadening is applied to that line. A special format is
used where alpha=abs(fix(GW)), sigma=GW-alpha.
If GW<-20, then sigma>1, and can be recovered as sigma=10*(abs(GW-fix(GW))).
GWrep - strarr(nlines): Human-readable GW, with sigma and alpha separated.
irad, jrad - intarr(nlines): Lower and upper level indices of spectral lines.
These map the spectral lines to atomic levels.
conf - strarr(nlevels): Electron configurations
term - strarr(nlevels): Spectroscopic terms
spec - strarr(nlevels): Species
ec, ev - dblarr(nlevels): Level energies, in units of cm^-1 and eV
converged, interpolated - bytarr(nabund,nteff,nlogg,nfeh): Diagnostic variables
indicating whether a point on the grid converged, or has been interpolated.
If neither flag is set, then curves of growth are not available for that
model.
```

## Author information

- Author:
Thomas Nordlander, RSAA/ANU

- History:
Change history:

`Written, 2017-12-20, TN Modified, 2018-01-22, TN: completely rewritten to use grids stored in structures. This improves portability and compatibility with GDL.`

## Project statistics

Directories: | 1 |

.pro files: | 1 |

.sav files: | 2 |

Routines: | 5 |

Lines: | 221 |