getTrk: Import stellar track data
In stellaR: Evolutionary Tracks and Isochrones from Pisa Stellar Evolution Database

getTrk

R Documentation

Import stellar track data

Description

Import a stellar evolutionary track from pre-main sequence to He flash and from ZAHB to thermal pulses.

Usage

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

Arguments

`m`	the mass, in unit of solar mass, of the model to get. Allowed values are 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10.
`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. See `Details` for further information.

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

getTrk returns an object of class trk; getHb returns an object of class hb.

More specifically these objects are lists with common elements:

`mass`	the mass of the model (in unit of solar mass)
`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: mod model number time logarithm of the evolutionary time (in yr) 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) Hc central H/He abundance logTc logarithm of the central temperature (Tc in K) logRHOc logarithm of the central density (RHOc in g cm^-3) MHEc mass of the He core (in unit of solar mass) Lpp luminosity of pp chain (in unit of total luminosity L) LCNO luminosity of CNO cycle (in unit of total luminosity L) L3a luminosity of triple-alpha (in unit of total luminosity L) Lg gravitational luminosity (in unit of total luminosity L) radius radius of the star (in unit of solar radius) logg logarithm of the surface gravity (g in cm s^-2) Only `time`, `logL`, and `logTe` are mandatory, while all other variables are optional.

hb class contains also the element:

massRGB

the mass of the RGB progenitor

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.

Examples


  ## Not run: 
  trk <- getTrk(0.9, 0.002, 0.25, 1.7, 0)

  ### get data from local directory /data
  trk <- getTrk(0.9, 0.002, 0.25, 1.7, 0, baseURL="/data/")

  ###  multi-panel plot of the various quantities with time
  track <- getTrk(0.80, 0.001, 0.25, 1.90, 0)
  if(!is.na(track)[1]) {
  trkdata <- within(stack(track$data), time <- rep(track$data$time,
      length.out=length(values)) )
  require(lattice)
  xyplot( values ~ time | ind, data=trkdata, type="l",
      scales=list(y=list(relation="free")))
  } 
## End(Not run)

stellaR documentation built on April 11, 2022, 5:09 p.m.