The structure of the Monoceros R2 molecular cloud core

We present the results of molecular line observations of Mon R2. Maps in lines tracing high density show an arclike structure surrounding the H II region. Maps of temperature deduced from H2CO line ratios reveal a hot spot with T-K >100 K coincident with a submillimeter continuum peak. Maps of density deduced from CS line ratios indicate that the density peaks near IRS 1 and declines away from it. The spherically averaged data can be modeled equally well with a power law (with an exponent of 0.8-0.9) or a Gaussian with an FWHM of 1.0 pc. In either case, densities in the central region are around 10(6) cm(-3). The derived density gradient suggests that the thermal pressure is not the only source of cloud support, and the relation between the density gradient and the cloud mass suggested from similar studies of other regions also holds in the Mon R2 cloud core.