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Access to the Phoenix Models for Synphot

The  Phoenix Models by France Allard and Collaborators offered with Synphot are for stars/brown dwarfs/planets  with a cloud model. The models here are from the author's AGSS2009 models which use the Asplund et al. (2009) solar abundances. These use static, spherical symmetric, 1D simulations to completely describe the atmospheric emission spectrum. The models account for the formation of molecular bands, such as those of water vapor (Barber & Tennyson BT2 2006), methane, or titanium dioxide, with no alpha element enhancement. More information about these models can be found in Allard et al. 2003, Allard et al. 2007,  Allard et al. 2012, and in the simulators home page at https://phoenix.ens-lyon.fr/simulator/index.faces

The models in this suite were resampled to reduce the number of points from the original models. We reduce it to 5,000 points across the 900 to 30 \(\mu m\) wavelength range. Each directory in this suite includes all the models for a given solar abundance. For example "phoenixm10" includes all the models for [M/H]=-1.0, where "m" is for minus and "p" is for plus. Each of the files in these directories is for a single Teff. These fits files have the wavelength in angstroms while the flux is in units of  \( erg\ cm^{-2}\ s^{-1}\ {\dot A}^{-1}\).  Each file has several columns for different log_g values, with the column name labeled accordingly. For example, the column for log_g = 4.0 has column name g40, while that for log_g=3.0 has column g30. For all metallicities, except for [M/H]= 0.0, each model includes columns for all log_gs in the range between 0.0 and 5.5. Those log_gs for which there are no phoenix models have FLAM=0 for all wavelengths.

We are in the process of replacing these models with an updated version that includes more data point and extend the wavelenth range to start at 10 \({\dot A}\). The new models have 100,000 points for each log_g. We have done this only for models with metallicity = 0.0. These files are also slightly different from the previous cases in which each file includes columns only for those log_gs for which the models exist; this is, not all the Teffs have the full range of log_gs, which in this case goes from 0.0 to 6.0. The list of log_g's included, as well as those missing, is provided in the header[0] of each file. Note also that we downloaded again the original models from the author's site at https://phoenix.ens-lyon.fr/Grids/BT-Settl/AGSS2009/SPECTRA/. The models for metallicity = 0.0 and stars with Teff > 2600K are from BT-Settl_M-0.0_a+0.0_hot.tar. For stars with Teff between 2000K and 2600 K, we downloaded them from BT-Settl_M-0.0_cool.tar.  Note that in this new set, as well as our original models, most models include four spectra per file (i.e., the wavelengths were repeated four times within a given file), where each had about 100,000 points or less. For these cases, we took only the first instance. There are a few cases where the full 400,000 points corresponded to a single instance of the spectrum.

The Phoenix models in our library were obtained on Nov. 14, 2011; those for [M/H]= 0.0 were downloaded on April 29, 2021. The individual models per solar abundance in our grid can be obtained from the following links:

These can also be downloaded from the MAST HSLP by solar metallicity or as a tar file.

References:

  • Allard, F., Guillot, T., Ludwig, H.-G., et al. 2003, IAU Symp., 211, 325
  • F. Allard , N. F. Allard , D. Homeier , J. Kielkopf , M. J. McCaughrean , and F. Spiegelman 2007, A&A, 474, L21

  • Allard, F., Homeier, D., Freytag, B. 2012, Phil. Trans. R. Soc. A., 370, 276 (in Allard's directories this reference has year 2009)

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