Spectral ANalog of Dwarfs (SAND) model atmospheres and Evolutionary Extension to SAND (SANDee) evolutionary models for low-mass stars and brown dwarfs

Spectral ANalog of Dwarfs (SAND) is a new grid of model atmospheres for low-mass stars and brown dwarfs at a variety of chemical compositions, characteristic of various components of the Milky Way, including the galactic halo and globular clusters. The models were calculated using PHOENIX 15

A detailed description of SAND is available in RNAAS 2024 by Alvarado, Gerasimov, Burgasser, Brooks, Aganze and Theissen [ADS]

Evolutionary Extension to SAND (SANDee) is a new grid of evolutionary models that uses the SAND models for synthetic photometry and as atmosphere boundary conditions. SANDee is the first set of models that can reproduce the observed star/brown dwarf transition in globular clusters. SANDee models were calculated using MESA 23.05.1

A detailed description of SANDee is available in ApJ 2024 by Gerasimov, Bedin, Burgasser, Apai, Nardiello, Alvarado and Anderson [ADS]

Directory structure:

SAND.zip                  :               SAND model atmospheres
    recommended           :                   Subset of SAND atmospheres whose synthetic photometry maintains continuity as a function of temperature
    rest                  :                   The rest of SAND models (see notes on convergence below)
SANDee.zip                :               SANDee evolutionary models
    BC                    :                   MESA atmosphere boundary condition tables for tau=100 at each chemistry
    MESA                  :                   MESA evolutionary models, organized first by chemistry, then by initial mass
isogen.zip                :               Python script to generate model isochrones from SANDee and SAND models
    isogen.py             :                   The script itself
    demo.ipynb            :                   Jupyter notebook that demonstrates how the script can be used
    vega_bohlin_2004.dat  :                   Standard spectrum of Vega for VEGAMAG photometry
    Other *.dat           :                   Transmission profiles for JWST filters used by the demo notebook
custom.patch              :               Patch with author's changes to the MESA codebase
HBL.mrt                   :               Estimated true hydrogen-burning limits for each SAND/SANDee chemistry