COSMOTOOLS V1.0
Cosmological Calculator

Alberto Cappi
INAF - Osservatorio Astronomico di Bologna

This program calculates a number of useful quantities (distances, angles and lookback time) given a cosmological model and a redshift. If you are interested in the formulae used here, look at my short introduction to cosmological formulae and check the links listed below. For any comments, suggestions or errors do not hesitate to send me an email.
This program is listed -among other cosmological calculators- by the Nasa Extragalactic Database (NED).

If you simply need the distance for the standard flat LambdaCDM model, you can use my WolframAlpha Widget:

Input parameters

Enter H0 ...............................................
Enter OmegaMatter ..............................
Enter OmegaLambda ...........................
Enter redshift ......................................

General properties of the model

Deceleration parameter q0 ....................
Omegak ..................... (Omegak = 1-OmegaM-OmegaLambda)
Age of the universe (Gyr) ......................

Values for the chosen redshift

Luminosity Distance (Mpc):
Comoving Distance (Mpc):
Angular Distance (Mpc):
Length corresponding to 1 degree (Mpc):
Angle corresponding to 1 Mpc (arcmin):
Lookback time (Gyr):

Useful links:

A. Cappi, Testing cosmological models with negative pressure, 2001, ApLC 40, 161 (astro-ph/0105382)
D.W. Hogg, Distance measures in cosmology, 1999 (astro-ph/9905116)
H. de Ruiter, Cosmological formulas, 2005

Written in JavaScript by Alberto Cappi. Last update: July 28, 2010

E-Mail: alberto.cappi@bo.astro.it

counts since December 9, 2005