STARFORMATION IN ORION NEBULAE: PROPLYDS

Abstract

We have constructed for the rst time the surface-brightness distributions arund 11 bright protostellar objects at three wavelengths. Our results indicate appreciable inhomogeneity in the distribution of the radiating matter around these
proplyds. The brightness distributions along the minor and major axes have asymmetrical, bell-like shapes.

The lengths of the tails of proplyds located within 16"of the star 1 Ori C depend on the distance to the ionizing star. Proplyds located closer to the star have shorter tails.
The distributions of matter in the protostellar disks differ substantially: The  brightness distributions along the minor diameter can be best fitted using a cubic polynomial, while the brightness distributions along the major diameter are better fitted with a power law with index a < 0. No wavelength dependence for the dimensions of the protostellar disks was found. The sizes of different objects in the violet, red, and IR can remain the same, increase, or decrease with wavelength. This is probably related to the physical and evolutionary states of individual objects. The mean absolute luminosities determined from the bright, crescent-shaped regions in the sources studied differ little from the solar luminosity.