The origins of ultra-high-energy cosmic rays (UHECRs)—which are the strongest particles in the universe—are still a puzzlement to scientists after decades of research. As a result of a new idea, these high-energy particles might come into existence during the mergers of neutron stars.
For Highly-energetic Cosmic Rays Understanding
UHECRs are really subatomic particles, like mostly protons or an atomic nucleus, having energy more than 10¹⁸ eV. To gloss this out, the “Oh-My-God” particle detected within 1991 largely has an energy of about 3.2 × 10²⁰ eV, very widely magnitudes over what could be achieved by human-made particle accelerators; much absolutely.
Many sources have been suggested for this unknown collection of extraordinarily energetic particles.
Recent studies have suggested that UHECRs are actually produced by binary neutron star (BNS) mergers. When two neutron stars collide and spiral inwards, following the supernova explosion, they create shock waves that cause a massive outflow of energy from the two stars. This event can give rise to relativistic jets, meaning very narrow beams of particles travelling very close to the speed of light.
Farrar’s study mentions that these jets produced by BNS mergers can accelerate particles to ultra-high energies. The almost symmetrical jets produced by the small mass range in such a merger make up the only acceptable explanation for the observed uniformity in UHECR energies.
Mechanisms of Acceleration of Particle
The processes through which particles gain such extreme energies as neutron star mergers involve:
Magnetohydrodynamic (MHD) Phenomena: The neutron stars have such remarkably strong magnetic fields and such rapid rotations that they can drive the formation of powerful MHD processes which would produce relativistic jets capable of accelerating particles to ultra-high energies.
Shock Acceleration: The jets interact with ambient material and generate shock waves that can energize particles through processes such as Fermi acceleration.
Observations and Perspectives Therein New avenues of research into these phenomena have been created by the detection of gravitational waves due to neutron star mergers, for example, the event GW170817 of 2017. None of these high-energy neutrinos have been detected from GW170817, but by keeping on observing, scientists hope to find any relation of those very events to high-energy cosmic rays or neutrinos.
The future would see even more advanced neutrinos and cosmic ray observatories. Much advancement is expected in measuring and analyzing these particles from neutron star mergers, which would both solve a great cosmic mystery and extend knowledge on particle acceleration in extreme astrophysical environments.
To sum up, the assertion that star mergers- more particularly neutron star mergers- are a viable candidate for accounting for the universe’s highest-energy particles certainly makes sense in light of the new observational evidence. Further studies in the field can only help clarify the origins of UHECRs and the most energetic phenomena in the universe.
