Gas density (left), gas temperature (centre), and ratio of gas and dust temperatures (right) after 200 orbits of the fiducial simulation. The latter is defined as min(T_gas,PRIZMO, T_DIAD)/T_dust,PRIZMO. The solid purple line is the sonic surface, while the dashed lines show streamlines at regular intervals. The grey lines in the right-hand panel show total column densities of N = 10²¹, 10²³, 10²⁵ cm⁻².