API

pygnuastro.cosmology.age	Returns the age of the universe at redshift z in units of Giga years.
pygnuastro.cosmology.angular_distance	Return the angular diameter distance to an object at redshift z in units of Mega parsecs.
pygnuastro.cosmology.to_absolute_mag	Return the conversion from apparent to absolute magnitude for an object at redshift z.
pygnuastro.cosmology.critical_density	Returns the critical density at redshift z in units of g/cm3.
pygnuastro.cosmology.comoving_volume	Returns the comoving volume over 4pi stradian to z in units of Mega parsecs cube.
pygnuastro.cosmology.proper_distance	Returns the proper distance to an object at redshift z in units of Mega parsecs.
pygnuastro.cosmology.luminosity_distance	Return the luminosity diameter distance to an object at redshift z in units of Mega parsecs.
pygnuastro.cosmology.distance_modulus	Return the distance modulus at redshift z (with no units).
pygnuastro.cosmology.velocity_from_z	Return the velocity (in km/s) corresponding to the given redshift (z).
pygnuastro.cosmology.z_from_velocity	Return the redshift corresponding to the given velocity (v in km/s).
pygnuastro.fits.img_read	Reads the contents of the 'hdu' extension/HDU of 'filename' into a NumPy array and returns it.
pygnuastro.fits.img_write	Write the input 'data' into the FITS file named 'filename'.