getIso: Import stellar isochrones data

Description Usage Arguments Details Value References See Also Examples

Description

Import a stellar isochrone.

Usage

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

Arguments

age

the age (in Gyr) of the isochrone to get. Allowed values are 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0.

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

getIso returns an object of class iso. More specifically this is a list with elements:

age

the age of the isochrone (in Gyr)

z

the metallicity of the model

y

the initial helium content of the model

alpha.enh

the mixing-length value of the model

data

the dataset of stellar isocrone, containing the following five variables:

logL

logarithm of the luminosity (L in unit of solar luminosity)

logTe

logarithm of the effective temperature (Te in K)

mass

mass of the star (in unit of solar mass)

radius

radius of the star (in unit of solar radius)

logg

logarithm of the surface gravity (g in cm s^-2)

print, and plot methods are available for the class.

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

getZahb, getHbgrid, getTrk, getTrkSet.

Examples

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  ## Not run: 
  iso <- getIso(12.0, 0.002, 0.25, 1.7, 0)

  ### get data from local directory /data
  iso <- getIso(12.0, 0.002, 0.25, 1.7, 0, baseURL="/data/")
## End(Not run)

Example output

Warning message:
In getIso(12, 0.002, 0.25, 1.7, 0) : CDS is unavailable; please try later
Warning message:
In getIso(12, 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.