CONCERNING AN EQUALITY BETWEEN THE NET RADIATIVE BRACKET AND ESCAPE PROBABILITY IN A MOVING MEDIUM

With reference to line photons within an isolated source, conditions which are known to be sufficient for an equality between the escape probability and the net radiative bracket for a constant source function have been summarized and one further condition has been identified, namely, a velocity field with constant velocity gradient irrespective of the shape of the absorption profile. This latter condition applies irrespective of the magnitude of the velocity gradient (and not just in the large velocity gradient limit). © 1990.