Optical Depth Estimates and Effective Critical Densities of Dense Gas Tracers in the Inner Parts of Nearby Galaxy Discs

M. J. Jimenez-Donaire, F. Bigiel, A. K. Leroy +17

High critical density molecular lines like HCN(1-0) or HCO+(1-0) represent our best tool to study currently star-forming, dense molecular gas at extragalactic distances. The optica…