Overview

• Scientists have observed unusually high ionization levels in hydrogen gas at the Milky Way's Central Molecular Zone (CMZ), a long-standing mystery in astrophysics.
• A new study suggests that the ionization may be caused by the annihilation of sub-GeV dark matter particles, which are much lighter than previously considered candidates like WIMPs.
• These particles could produce electron-positron pairs, providing energy to ionize hydrogen and potentially explaining the galaxy's enigmatic 511 keV gamma-ray signal.
• If confirmed, this would mark a significant breakthrough in dark matter research, potentially shifting focus toward lighter, harder-to-detect particles.
• Future missions like NASA's COSI telescope, launching in 2027, may provide critical data to test this hypothesis and deepen our understanding of dark matter.