getZahb function

Import stellar track data for ZAHB

Import stellar track data for ZAHB

Import a stellar ZAHB model.

getZahb(z, y, ml, afe,
           baseURL="ftp://cdsarc.u-strasbg.fr/pub/cats/J/A+A/540/A26/")

Arguments

  • z: the initial metallicity of the model to get. Allowed values are 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, 0.0009, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01.
  • y: the initial helium abundance of the model to get. Allowed values are 0.25, 0.27, 0.33, 0.38, 0.42.
  • ml: the mixing-length of the model to get. Allowed values are 1.7, 1.8, 1.9.
  • afe: the alpha-enhanchment of the model to get. It can be one of afe = 0 for [alpha/Fe] = 0.0 or afe = 1 for [alpha/Fe] = 0.3.
  • baseURL: the URL of the base directory of the database from where get the models.

Returns

getZahb returns an object of class zahb

More specifically it is a list with elements: - z: the metallicity of the model

  • y: the initial helium content of the model

  • ml: the mixing-length value of the model

  • alpha.enh: the alpha-enhanchment of the model. It can be one of alpha.enh = 0 for [alpha/Fe] = 0.0 or alpha.enh = 1 for [alpha/Fe] = 0.3.

  • data: the dataset of stellar track, containing the following variables:

    • mass: mass of the star (in unit of solar mass)
    • logTe: logarithm of the effective temperature (Te in K)
    • logL: logarithm of the luminosity (L in unit of solar luminosity)

print, and plot methods are available for the two classes.

If baseURL points to an invalid path or CDS ftp site is unavailable the function returns NA and issues a warning.

Details

As a sanity check, the function performs a consistency test on the parameters z, y, ml, afe by a call to testComposition.

By default the function requires an Internet access for data gathering. Tracks and isochrones are downloaded from the on-line repository CDS (http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/540/A26) It is also possible to gather data from a local download of the catalog, specifying as baseURL the root directory of the download. In this case the structure of the catalog and the names of files and directory must be preserved.

See Also

getTrk, getHbgrid, getIso, getTrkSet.

References

M. Dell'Omodarme, G. Valle, S. Degl'Innocenti, and P.G. Prada Moroni (2012). The Pisa Stellar Evolution Data Base for low-mass stars. Astronomy and Astrophysics, 540, A26.

Examples

## Not run:

  zahb <- getZahb(0.002, 0.25, 1.7, 0)

  ### get data from local directory /data
  zahb <- getZahb(0.002, 0.25, 1.7, 0, baseURL="/data/")
## End(Not run)
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