eROSITA Telescope Separates Solar System X-ray Glow from Deep-Space Signals

Scientists at the Max Planck Institute for Extraterrestrial Physics have successfully separated X-ray emissions originating within our solar system from those coming from deep space, using data from the SRG/eROSITA space telescope. The telescope, positioned approximately 1.5 million kilometers from Earth—roughly four times the distance to the Moon—collected four sky maps between 2019 and 2021 that enabled researchers to isolate solar-wind charge exchange (SWCX) emission.

The achievement addresses a longstanding challenge in X-ray astronomy: distinguishing between local and distant X-ray sources. By analyzing multiple sky maps from eROSITA's unique vantage point, the team was able to extract the contribution of SWCX emission, which occurs when charged particles from the solar wind interact with neutral atoms in the solar system. This separation allows astronomers to more accurately study X-ray signals from distant cosmic sources without contamination from our own solar neighborhood. The research has been published in a peer-reviewed journal.