2013MNRAS.429.3166G

Observations show that some molecular cloud cores are prolate. In this paper, we investigate the effects of surface heating due to an external radiation source on the shape of molecular cloud cores. We limit our investigation to the particular case in which the cloud core is quiescent and the effect of magnetic fields is negligible. Thus, we only consider the thermal effects of the external radiation source. When the external radiation source illuminates one side of a core preferentially, a temperature gradient results across it. In the steady state, we use the Laplace equation to find the temperature profile through the core and then we solve the density structure using the finite-difference method. The results show that the surface heating caused by an external radiation source is a suitable candidate for the transformation of cores to a prolate shape. These results are in conformity with observational results of quiescent cores within the Orion cloud.