Charge Exchange X-ray Emission in the Heliosphere and Beyond

Charge exchange (CX) is a basic physical process involving the transfer of bound electrons between colliding particles. In the solar system, highly-charged solar wind ions collide with neutral particles from cometary and planetary (e. g. Mars, Earth) environments, as well as interstellar atoms sweeping through the heliosphere, and produce X-rays through radiative decay. I will present an overview of our current knowledge of the CX X-ray emission, focusing mainly on the heliospheric component which, along with CX emission from the Earth's geocorona, surrounds Earth-bound observatories and adds a variable background to all X-ray observations. Current studies combine theoretical modeling and observational analyses from Suzaku, XMM-Newton and Chandra in order to constrain this emission and its contribution to the diffuse soft X-ray background.