Luminosity, redshift and gas abundance in general relativistic radiation   hydrodynamics
  Quasi-stationary flows of gas accreting onto a compact center are analyzed in the framework of general-relativistic radiation hydrodynamics, under assumptions of spherical symmetry and thin gas approximation. Numerical investigation shows that luminosity, redshift and gas abundance are correlated. The gas can constitute up to one third of the total mass of brightest low-redshift sources, but its abundance goes down to 1/30 for sources with luminosities close to the Eddington limit. 
Janusz Karkowski, Edward Malec, Krzysztof Roszkowski, Zdobyslaw   Swierczynski