A recent astronomical observation recorded the presence of very high-energy gamma rays emanating from the vicinity of the pulsar Geminga. The measurement reached the mark of 100 trillion electron volts, representing the highest energy range ever documented for this specific type of celestial phenomenon.
The study target is located approximately 800 light-years away from Terra, positioned in the constellation of Gêmeos. Esta neutron star is historically recognized by the scientific community as the second brightest source of visible gamma radiation in the entire night sky.
The data collected offers a direct window into the extreme particle acceleration processes occurring in deep space. Mapping these emissions provides fundamental answers about the origin, composition and behavior of cosmic rays that travel through the universe.
Observation dynamics in the Tibete infrastructure
The capture of these high-energy signals was made possible by the infrastructure of the AS-gamma experiment, an international scientific installation located at an altitude of 4,300 meters in the autonomous region of Tibete. The complex operates a vast network of surface detectors combined with underground Cherenkov water muon sensors designed to capture the atmospheric shower of secondary particles generated when cosmic radiation reaches Earth’s atmosphere.
By analyzing the angle, distribution and energy of these secondary particles, researchers are able to accurately reconstruct the trajectory and original power of the gamma rays before they entered the Earth’s environment. The high altitude of the installation minimizes the loss of information during the atmospheric cascade, while underground sensors filter out background interference, allowing a clean reading of signals originating from the Gêmeos constellation.
Particle behavior and magnetic fields
Cosmic rays are essentially highly energetic charged particles that constantly bombard the Earth’s environment. Its exact origin remains one of the biggest questions in modern astrophysics due to the physical nature of its movement through the cosmos.
Because they have an electrical charge, these particles interact directly with the interstellar magnetic fields spread throughout the galaxy. Esta interaction causes their trajectories to be continually diverted, creating a chaotic path that makes it impossible to track in a straight line back to their generating source.
To overcome this technical limitation, the observation of gamma rays appears as the most effective methodological alternative. Diferente of charged particles, gamma radiation is made up of photons, which have no electrical charge and travel in an absolutely straight line through space.
These photons function as direct messengers, pointing exactly to the location where the extreme acceleration events occurred. Eles are generated when highly energetic electrons collide with surrounding low-energy photons, transferring colossal amounts of force in a process known as inverse Compton scattering.
Formation of the stellar radioactive halo
Geminga is an ancient pulsar, estimated to be 300,000 years old, characterized by its rapid rotation and intense emission of radiation beams. Around this dense stellar core, the expelled plasma forms a violent wind that constantly collides with the remains of the original supernova.
This continuous collision acts like a gigantic natural particle accelerator, pushing electrons and positrons to extreme speeds. The result of this interaction is the formation of a pulsar wind nebula, which visually manifests itself as a vast, ring-shaped halo of gamma rays surrounding the dead star.
Energy Limits and Space Acceleration
Recent mapping of this halo revealed that the intensity of gamma rays drops drastically when the energy exceeds the 100 TeV barrier. Esta specific measurement establishes the critical limit of electron acceleration within the Geminga nebula, providing a precise mathematical parameter for physical models.
The definition of this energy ceiling is a milestone for understanding how different celestial bodies manage their internal forces. Comparing these numbers with other sources, such as Nebulosa and Caranguejo, which reach the petaelectronvolt scale, demonstrates that age and the surrounding environment directly dictate the accelerating capacity of a pulsar.
Electron retention and the diffusion coefficient
Another aspect detailed by the measurements involves the diffusion coefficient in the region immediately close to the star. Este index determines the speed and ease with which cosmic ray particles can escape local magnetic turbulence and spread throughout open space.
The data indicated that the diffusion rate around Geminga amounts to just one hundredth of the standard value observed in the rest of the interstellar medium. Este extremely low number indicates severe suppression in particle mobility within that specific zone.
In practical terms, this means that the electrons and positrons generated by the pulsar are mostly trapped in its surroundings. The local magnetic structure acts as a containment barrier, preventing the rapid dispersal of this highly energetic material to the rest of the galaxy.
Resolution of excess positrons in astrophysics
The discovery of this intense particle retention capacity provides the missing piece to resolve a long-standing discrepancy in astronomical observations regarding the amount of antimatter reaching the solar system. Durante decades, instruments in Terra’s orbit detected a volume of high-energy positrons far greater than what standard theoretical models of cosmic ray propagation could explain. The confirmation that ancient pulsars like Geminga operate as massive traps that release these particles slowly over millennia aligns perfectly with the mathematical models needed to justify this excess. The slow diffusion of trapped positrons creates a constant and delayed flow of antimatter, explaining exactly the anomalous readings captured by terrestrial equipment and definitively linking the dynamics of pulsar wind nebulae to the composition of the cosmic radiation that bathes the planetary neighborhood.
Continuous mapping of deep space
The consolidation of these data sets a new standard for the observation of high-energy phenomena in the galactic neighborhood. Continuous monitoring of similar sources will allow the creation of a detailed map of the natural accelerators present in Via Láctea, refining the understanding of the extreme physics that governs the universe.