Published July 28, 2021 | Version 1.0
Dataset Open

Theoretical Models of Ultra-Cool Objects (Brown Dwarfs and Free-Floating Planets) Including Water Latent Heat Effect: Thermal Structure, Spectra, and Photometry

  • 1. Lowell Observatory; Department of Astronomy and Planetary Science, NAU
  • 2. Department of Astronomy and Planetary Science, NAU; Habitability, Atmospheres, and Biosignatures Laboratory, NAU; NASA Astrobiology Institute's Virtual Planetary Laboratory, University of Washington
  • 3. Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona
  • 4. Space Sciences Division, NASA Ames Research Center
  • 5. BAER Institute, NASA Ames Research Center, Naval Air Station


Data presented here are from the work of Tang et al. (2021), which present a one-dimensional (vertical) atmospheric structure model for ultra-cool objects
that includes moist adiabatic convection (water latent heat release effect).
Model grids across a range of effective temperatures (350, 300, 250, 200 K), metallicities ([M/H] of 0.0, 0.5, 0.7, 1.5),
and gravities (logg of 4.0, 4.5, 4.7, 5.0) that mimic the atmosphere condition of Y-class brown dwarf and Free-Floating Planets.

The pressure-temperature profile are saved under the ./pT_profiles/, which have two folders:

  1. pT_profile_dry_adiabat: for dry adiabatic treatment.
  2. pT_profile_moist_adiabat: for moist adiabatic treatment.

File name of each compressed files gives the effective temperature (Teff, in Kelvin), gravity (in MKS), and metallicity (in [M/H]) information as for example:
t200g100nc_m0.0.cmp.gz --> Teff of 200K, gravity as 100 m/s2, and [M/H]=0.0.

The table formate of the pressure-temperature profile, i.e., the .cmp files, is made to work with the [PICASO software](
Each .cmp file contains

  • Column 01   (x)                   : atmosphere pressure level
  • Column 02   (pressure)       : atmosphere pressure in bar
  • Column 03   (DEN)              : atmosphere density in cm^{-3}
  • Column 04   (temperature) : atmosphere temperature in kelvin
  • Column 05-14                    : molecule mixing ratios for H2, He, CH4, H2O, NH3, CO, PH3, H2S, N2, CO2
  • Column 15   (MU)               : mean molecular weight in grams/mole

Model spectra are saved under the ./spectra/ with wavelength ranging from 1 to 30 micron.
File name of each compressed file gives the effective temperature (Teff, in Kelvin), gravity (in MKS), metallicity (in [M/H]), adiabatic treatment, and
the resolving power information as for example:
sp_t200_g100_m0.0_dry_R3000.csv.gz --> Teff of 200K, gravity as 100 m/s2, [M/H]=0.0, with dry adiabatic treatment, and R=3000.
Each spetrum .cv file contains two columns:

  • Column 01 wavelength [micron]
  • Column 02 Flux            [W/m2/micron], the spectral fluxes are given at the top of the atmosphere, taken to be 1 Jupiter radius.

Photometry data derived from the spectra at the top of the atmosphere (assuming one Jupiter radius) are given in the syn_photometry.csv.
Photometry filters are from the Mauna Kea Observatory (MKO) photometry system, the Wide-field Infrared Survey Explorer (WISE), and the
Spitzer Space Telescope. Filter profiles and Vega magnitude zero points are from the [SVO Filter Profile Service](

  • Column 01 (gravity)  , gravity in MKS
  • Column 02 (teff)       , effective temperature in Kelvin
  • Column 03 ([M/H])    , metallicity
  • Column 04-12           , photometry magnitude for IRAC36, IRAC45, W1, W2, GiminiM, MKO_J, MKO_H, MKO_K, MKO_Lp all in Vega system.
  • Column 13 (adiabatic), adiabatic treatment; D: dry adiabatic, M: moist adiabatic

Please cite Tang et al. (2021, Astrophysical Journal, in press.)
[ADS link]( if you used data here in your research.


Files (29.3 MB)

Name Size Download all
29.3 MB Preview Download