'Angular separation in arcsec corresponding to a comoving kpc
at redshift ``z``.
Parameters
z : array-like
Input redshifts.  Must be 1D or scalar.
Returns
theta : `~astropy.units.Quantity`
The angular separation in arcsec corresponding to a comoving kpc
at each input redshift.'

def arcsec_per_kpc_comoving(self, z):

    return (u.arcsec / (self.comoving_transverse_distance(z).to(u.kpc) * arcsec_in_radians))
