All articles tagged with #ultrahigh energy cosmic rays
New simulations suggest ultrahigh-energy cosmic rays hitting Earth could be atomic nuclei heavier than iron, which lose energy more slowly over cosmic distances; events like neutron-star mergers or massive star collapses into black holes may accelerate these ultraheavy nuclei, reshaping how scientists search for their sources and understand cosmic-ray acceleration.
NASA's Fermi Gamma-ray Space Telescope has detected an unexpected gamma-ray feature beyond our galaxy, which is 10 times stronger than expected and located far from the cosmic microwave background (CMB) dipole. This discovery, presented at the American Astronomical Society meeting, suggests a link between the gamma-ray signal and ultrahigh-energy cosmic rays, both exhibiting similar magnitudes and directions. The findings challenge current understanding of astrophysical processes and may provide insights into the early universe.