New type of collisionless shock observed by Venus Express Conference Paper uri icon


  • The overshoot-undershoot structure at the front of a quasiperpendicular colissionless shock has always been regarded as evidence of supercriticality and sign of ion reflection. Subcritical shocks have been classified as either dissipative or dispersive. In a quasiperpendicular case both type do not posses oscillatory structure downstream of the ramp. Here we present for the first time low a series of Mach number subcritical quasiperpendicular shocks that possess overshootundershoot structure It is shown that its unusual structure is due to kinematic collisionless relaxation of downstream ions.

publication date

  • January 1, 2008