def HIMassToFlux( M_HI, dist_Mpc ):
	"""Converts H I mass (in solar masses) to equivalent H I flux (in Jy km/s)
	based on distance in Mpc.  Equation originally from Giovanelli & Haynes
	(1988, in Galactic and extragalactic radio astronomy (2nd edition), p.522),
	based on Roberts (1975, n A. Sandage, M. Sandage, and J. Kristian (eds.), 
	Galaxies and the Universe. Chicago:	University of Chicago Press; p.	309).
	"""
	return M_HI / (2.356e5 * dist_Mpc**2)