A detailed infrared study of the star forming region NGC2071 IRS

Abstract

This thesis presents measurements made at infrared (IR) wavelengths of the bipolar outflow in NGC2071. The observing methods at these wavelengths, the results of these data, and the nature of this outflow are discussed.
The first JHK and NBL high spatial resolution images of the NGC2071IR region are presented in this thesis. A 5' x 9' K band image and contour map of NGC2071 are presented, as is the first high resolution K band polarimetry of the cluster of near-IR sources in the core of this bipolar outflow. The nature of these IR sources are analysed and discussed individually and collectively. IRS1 is a highly polarized pre-main-sequence star which is most likely the generating source of the bipolar outflow; IRS2, 4 and 6 are stellar-like objects with low polarization; IRS4, and IRS6 are background stars showing some reddening due to dust from the outflow; IRS7 appears to be a pre-main-sequence star embedded in the cloud with a circumstellar shell while IRS2 could be either: 1) a background star contaminated by dust from the bipolar outflow or 2) a deeply embedded pre-main-sequence star. IRS5 and IRS5A are molecular hydrogen emission peaks, due to an infrared jet from IRS1, which appears to be changing positions on a four year time-scale.
Although the outflow in NGC2071 has, until now, been considered a single out­flow, data presented in this thesis lends support to this outflow being a composite of two and possibly even three outflows.