getZahb: Import stellar track data for ZAHB

Description Usage Arguments Details Value References See Also Examples

Description

Import a stellar ZAHB model.

Usage

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 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.

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.

Value

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.

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.

See Also

getTrk, getHbgrid, getIso, getTrkSet.

Examples

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  ## 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)

Example output

Warning message:
In getZahb(0.002, 0.25, 1.7, 0) : CDS is unavailable; please try later
Warning message:
In getZahb(0.002, 0.25, 1.7, 0, baseURL = "/data/") :
  data file not found; please check path

stellaR documentation built on May 2, 2019, 2:45 a.m.