相关论文: Ultra Heavy Cosmic Rays from Magnetars
We discuss several effects due to lensing of ultra high energy cosmic rays by the regular component of the galactic magnetic field. Large flux magnification around caustics can be a significant source of clustering in the arrival directions…
Ultramagnetized neutron stars or magnetars are magnetically powered neutron stars. Their strong magnetic fields dominate the physical processes in their crusts and their surroundings. The past few years have seen several advances in our…
It is shown that bulk acceleration during reconnection of extremely strong magnetic fields near compact objects can accelerate ions to Lorentz factors of $\sim 10^2 \sigma^{3/5}$ under general conditions, where $\sigma$, the magnetic energy…
A striking concentration of ultra-high energy cosmic ray (UHECR) events observed by the Pierre Auger Observatory around the direction of the nearby radio galaxy Centaurus A revives the idea that radio galaxies may be dominant sources of…
Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons would also generate neutrinos through interactions with ambient matter and/or…
Recent measurements by the Pierre Auger Observatory suggest that the composition of ultra-high energy cosmic rays (UHECRs) becomes dominated by heavy nuclei at high energies. However, until now there has been no astrophysical motivation for…
Ultra-high energy cosmic rays are mostly charged particles and they are therefore deflected by magnetic fields on their path from their sources to Earth. An interesting phenomenon arising from these deflections is the appearance of multiple…
We calculate for the nearest active galactic nucleus (AGN), Centaurus A, the flux of high energy cosmic rays and of accompanying secondary photons and neutrinos expected from hadronic interactions in the source. We use as two basic models…
We here investigate the possibility that the ultra-high energy cosmic ray (UHECR) events observed above the GZK limit are mostly protons accelerated in econnection sites just above the magnetosphere of newborn millisecond pulsars which are…
High-energy cosmic rays can be accelerated in clusters of galaxies, by mega-parsec scale shocks induced by accretion of gas during the formation of large-scale structure, or by powerful sources harbored in clusters. Once accelerated, the…
We review the physics of the highest energy cosmic rays. The discovery of their sources, still unknown, will reveal the most energetic astrophysical objects in the universe and could unveil new physics beyond the standard model of particle…
Among the many different classes of stellar objects, neutron stars provide a unique environment where we can test (at the same time) our understanding of matter with extreme density, temperature, and magnetic field. In particular, the…
Cosmic rays scattering with neutrinos produced in supernovae induce a flux of supernova neutrinos boosted to high energies. We calculate the neutrino flux arising from this new mechanism in environments with large cosmic-ray and supernova…
The propagation of ultra high energy cosmic rays in Galactic and extragalactic magnetic fields is investigated in the present paper. The motion of charged particles of different energies and chemical composition is simulated using different…
Neutron stars are one of the most exotic objects in the universe and a unique laboratory to study the nuclear matter above the nuclear saturation density. In this work, we study the equation of state of the nuclear matter within a…
The existence of neutron star mergers has been supported since the discovery of the binary pulsar and the observation of its orbital energy loss, consistent with General Relativity. They are considered nucleosynthesis sites of the rapid…
Merging neutron star binaries are prime candidate sources for heavy r-process nucleosynthesis. The amount of heavy r-process material is consistent with the mass ejection and rates of mergers, and abundances of relic radioactive materials…
We explore scenarios where the highest energy cosmic rays are produced by new particle physics near the grand unification scale. Using detailed numerical simulations of extragalactic nucleon, gamma-ray, and neutrino propagation, we show the…
Neutron star mergers have been proposed as the main source of heavy $r$-process nucleosynthesis in the Universe. However, the mergers' significant expected delay after binary formation is in tension with observed very early $r$-process…
Three times of supergiant flares from soft $\gamma$-ray repeatres are observed, with typical released energy of $\sim 10^{44-47}$ erg. A conventional model (i.e., the magnetar model) for such events is catastrophic magnetism-powered…