Temporal Variations of Charge-Exchange induced Heliospheric X-rays: Constraints on the Local Interstellar X-ray Background

International audience; We study the EUV/soft X-ray emission generated by charge transfer between solar wind heavy ions and interstellar H and He neutral atoms in the inner Heliosphere. We first present heliospheric maps for average stationary solar wind, depending on solar cycle phase, solar wind anisotropies and composition, line of sight direction and observer position. In a second step we introduce time dependence. A series of simulations of the X-ray intensities variations due to temporary solar wind enhancements are compared with XMM Newton recorded spectra at different intervals in the period 2000-2003. Results show that the heliospheric component can explain a large fraction of (if not all) the line intensity below 1.3 keV, strongly attenuating the need for soft X-ray emission from the Local Interstellar Bubble. We finally briefly discuss the potential role of charge-transfer X-ray emission from other astrophysical objects.