Identifying Shock-drift Acceleration at Quasiperpendicular Shocks: Simulations and MMS Observations

Collisionless shock play an important role in the heliosphere by governing the transition between different space environments, such as the transition from the solar wind to the magnetosheath at Earth's bow shock. The non-thermal acceleration of particles arising at collisionless shocks leads to hazards for spaceborne technology and human space exploration. Shock-drift acceleration is a well known process occurring at quasiperpendicular shocks that leads to the reflection and acceleration of a fraction of the incoming solar wind plasma. Here, we use the field-particle correlation technique to identify the unique velocity-space signature of shock-drift acceleration using a suite of hybrid simulations of Earth's bowshock. We also present the first use of this technique to identify shock-drift acceleration using observations of an almost exactly perpendicular shock by the Magnetospheric MultiScale (MMS) mission. This work provides a novel foundation for future efforts to generate predictive models of the energy partitioning through collisionless shocks as a function of the upstream shock parameters.