AN ANALYSIS OF THE INFRARED REFLECTION NEBULA AND CIRCUMSTELLAR ENVIRONMENT OF GL-2136

The star formation region GL 2136 has been imaged using narrowband fil ters at 2.2, 3.08, and 3.45 mu m. Water ice absorption at 3.08 mu m is commonly seen in molecular clouds toward embedded objects such as GL 2136. By constructing and analyzing a water ice absorption map and a M -2.2 - M-3.45 color map, we are able to set constraints upon the locat ion, size, and scattering properties:of grains in the GL 2136 region. Through detailed modeling of the composition and size distribution of the grains in the reflection nebula, we calculate a dust photospheric temperature of 660 K for IRS 1. Our analysis indicates that absorption is occurring within a circumstellar disk in addition to absorption in the molecular cloud. For the density of water ice in the molecular cl oud, we find an upper limit of 7 H2O molecules cm(-3) and a water ice abundance of 1.2 x 10(-5) by number with respect to hydrogen. The sout h and east lobes of the reflection nebula have small values of M-2.2 - M-3.45 and tau(ice) compared to those of IRS 1, and appear to line a c onical cavity created by the blueshifted molecular outflow. From the a pparent positions of the reflection lobes, the estimated opening angle of the outflow is 45 degrees. We also present a schematic diagram of the geometry of the region as determined by the results of this study.