A HIGH-RESOLUTION H-I SURVEY OF THE ROSETTE NEBULA

As part of the Boston University-Arecibo Galactic H I Survey, we analy zed the gross physical properties of the atomic gas associated with th e Rosette Molecular Complex (RMC) which was derived from a new, high-r esolution 21 cm survey. At the distance of the RMC, the 4' angular res olution of the survey corresponds to a linear size of 2 pc. The H I ma ps presented here cover an area of 110 x 60 pc. If the 21 cm emission is optically thin, then the survey mapped an H I mass of 1.5 +/- 0.1 x 10(5) M.. The optical nebula is surrounded by three dense H I regions , which roughly trace out the boundary of an H I shell. The shell is l ocated at the periphery of the atomic cloud and is expanding into the cloud at 4.5 km s-1. The expansion center is located at (1, b, v) = (2 06.266-degrees, - 2.083-degrees, 16.0 km s-1). A constant expansion ve locity implies a dynamical age for the shell of approximately 4 millio n years, which is consistent with the age of the central cluster NGC 2 244. The total kinetic energy of the expansion is estimated to be 3.8 x 10(48) ergs. This represents approximately 2% of the total (radiativ e + mechanical) energy available from the central cluster. Thus the ce ntral cluster can provide sufficient energy to power the flow through a combination of stellar winds and radiation.