Density and Temperature Structure of TMC‐1C from 450 and 850 Micron Maps

We have mapped the central 10'x10' of the dense core TMC-1C at 450 and 850microns using SCUBA on the James Clerk Maxwell Telescope. The unusually highquality of the 450 micron map allows us to make a detailed analysis of thetemperature and column density profiles of the core. We find that the dusttemperature at the center of TMC-1C is 7 K, rising to 11 K at the edges. Wediscuss the possibility and effects of a variable emissivity spectral index onthe derived mass profile. The low dust temperature of TMC-1C results in a highderived mass for the core, significantly larger than the virial mass estimatedfrom the linewidth of the N2H+ (1-0) transition. This result is valid within awide range of dust properties and ellipticities of the core. The N2H+ (1-0)spectra, taken with the IRAM 30m telescope, show signs of self-absorption,which provide evidence of sub-sonic infall motions. The derived density profileand infall velocity is compared to the predictions of several popular starformation models, and the Bonnor-Ebert model isthe best fit analytic model.Comment: 38 pages, 13 Figures, accepted to Ap