'Return the CMB temperature at redshift ``z``.
Parameters
z : array-like
Input redshifts.
Returns
Tcmb : `~astropy.units.Quantity`
The temperature of the CMB in K.'

def Tcmb(self, z):

    if isiterable(z):
        z = np.asarray(z)
    return (self._Tcmb0 * (1.0 + z))
