A Near Infrared Survey of the Orion Molecular Cloud 2 Region

by John Curtis Mergen

Under the supervision of Professors Robert D. Gehrz and Terry J. Jones

ABSTRACT

Presented is a near-infrared survey at 1.25-2.2 micron of a 0.025 sq. deg. region surrounding the core of Orion Molecular Cloud 2 (OMC-2). Analysis of the source counts and colors indicate that the majority of the sources brighter than K = +13 are not field stars. They must be members of a young association or associations within the survey area. The K band luminosity function (corrected for field star contamination using model calculations) exhibits a drop in counts at magnitudes fainter than K= +13 (~0.15 solar luminosities). This is most easily explained by assuming that the association(s) are young. The lowest mass stars are still in their pre-main sequence stage of evolution and have not yet "contracted" onto the main sequence. The distribution of colors across the region shows moderate correlation with molecular gas, but both reddened and unreddened stars are present along most lines of sight. Considerable reflection nebulosity is present in the core cluster region of OMC-2. Of particular interest are the thin streamers emanating from the star J9, which may be the remnant of a bipolar nebula produced by the star in the recent past. Several sources in OMC-2 appear variable. This is not unexpected for young stellar objects.