cosmo: Cosmological distances

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/cosmo.r

Calculates the angular diameter scale corresponding to the angular diameter distance at redshift z.

1	ascale(z, ...)

`z`	redshift
`...`	cosmological parameters, if needed

The default cosmological parameters assumed are H0=70 km/sec/Mpc, Omega_m=0.27, Omega_lambda=1-Omega_m.

The angular scale in kpc/arcsec

M.L. Peck

Hogg, D.W., 2000, "Distance measures in cosmology," http://arxiv.org/abs/astro-ph/9905116.

dcos

ascale(.05)
##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (z, ...) 
{
    dA <- dcos(z, ...)$dA * 1000
    dA * tan(pi/(180 * 3600))
  }