Some Restrictions on Models of Quasi-stellar Objects

Abstract

IT was shown in a previous article¹ that the inverse Compton process sets severe boundary conditions on the kinds of models of quasi-stellar objects that are compatible with the idea that they are at cosmological distances. In that article it was also shown that the condition that the synchrotron process is responsible for the continuous radiation from these objects leads, if they are at cosmological distances, to a class of model very different from those discussed previously. The restriction stems from the very high density of radiation which must be present in the objects. The total flux emitted if the objects are at cosmological distances is ∼ 10⁴⁷ ergs/ sec, and for an isotropic radiation field the energy density U_rad = L/πR²c where R is the dimension of the object. In our previous communication we took a value R≃10¹⁷ cm, suggested by the fluctuation data, so that U_rad≃100 ergs/cm³. If the objects are much closer, that is, if they are local, then U_rad≃10⁻⁴ ergs/cm³, and the inverse Compton effect is negligible.