The dust particle density [cm³] and gas density [g cm^-3] (left); and the gas velocity [km s^-1] and gas temperature [K] (right) for a simulation with an ambient medium temperature of 100 K (simulation A). Although the shocks are smooth, the contact discontinuity shows extensive instabilities, which start small at the front of the shock and grow as they move downstream. The dust concentration follows the contact discontinuity.