Juan Carlos Díaz Vélez
University of Wisconsin-Madison
Ground Observations of the Spectrum, Composition, and Anisotropy of Galactic Cosmic Rays
Since the discovery of cosmic rays, scientists have investigated their energy spectra, mass composition, and arrival direction distribution. These measurements provide insights into the astrophysical processes that accelerate these particles to extreme energies and offer clues about their sources and propagation through space. Recent observations reveal that the energy spectra of several cosmic-ray species deviate from a pure power law, exhibiting structures that depend on mass composition. Additionally, the distribution of arrival directions of cosmic rays appears to have a similar dependence on magnetic rigidity pointing to possible different dominant source populations at different energy scales below the knee.