Elongated Structures Near Young Stars: Jets or Projection Effects?

Abstract

Recent observations in radio, infrared and visible wavelengths have revealed the presence of small, elongated gaseous structures that appear to emanate from young stars. These structures are frequently interpreted as jets, perhaps similar in nature to those observed in extragalactic objects. We argue that these apparent “jets” could simply be light emitted by, or reflected from the walls of the cavities expected to be formed when the winds of these young stars drive their surrounding gaseous medium away. When viewed from certain positions the radiation from the walls of these cavities appears to the observer as elongated structures. A simple model is presented to illustrate this projection effect.