Related papers: Cosmic Rays from Pulsars and Magnetars
We consider the possibility that the excess of cosmic rays near $\sim 10^{18}$ eV, reported by the AGASA and SUGAR groups from the direction of the Galactic Center, is caused by a young, very fast pulsar in the high density medium. The…
Recent studies suggest that pulsars could be strong sources of TeV muon neutrinos provided positive ions are accelerated by pulsar polar caps to PeV energies. In such a situation muon neutrinos are produced through the delta resonance in…
We show that the observed fluxes, spectra and sky distributions of the high energy diffuse backgrounds of astronomical neutrinos, gamma rays and cosmic ray positrons satisfy simple relations expected from their common production in hadronic…
The merger of a neutron star (NS) binary may result in the formation of a long-lived, or indefinitely stable, millisecond magnetar remnant surrounded by a low-mass ejecta shell. A portion of the magnetar's prodigious rotational energy is…
Interpretations of synchrotron observations often assume a tight correlation between magnetic and cosmic ray energy densities. We examine this assumption using both test-particle simulations of cosmic rays and MHD simulations which include…
Observations of diffuse gamma rays above hundreds of TeV from the Galactic disk provide strong evidence for the existence of PeV cosmic-ray accelerators--so-called PeVatrons--in the Galaxy. However, mounting observations have ruled out most…
Contribution of nearby pulsars to the cosmic rays observed at Earth has been studied. It is found that the experimental bound on amplitude of cosmic ray anisotropy may produce significant constraint on the efficiency of converting pulsar…
The search for the origin of cosmic rays is a quest of almost a hundred years. A recent theoretical proposal gives quantitative predictions, which can be tested with data. Specifically, it has been suggested, that all cosmic rays can be…
The HAWC Collaboration has recently reported the detection of bright and spatially extended multi-TeV gamma-ray emission from Geminga, Monogem, and a handful of other nearby, middle-aged pulsars. The angular profile of the emission observed…
The total cosmic-ray luminosity of the Galaxy is an important constraint on models of cosmic-ray generation. The diffuse high energy $\gamma$-ray and radio-synchrotron emissions of the Milky Way are used to derive this luminosity. The…
The role pulsar wind nebulae play in producing our locally observed cosmic ray spectrum remains murky, yet intriguing. Pulsar wind nebulae are born and evolve in conjunction with SNRs, which are favored sites of Galactic cosmic ray…
The ratio between secondary and primary cosmic ray particles is the main source of information about cosmic ray propagation in the Galaxy. Primary cosmic rays are thought to be accelerated mainly in Supernova Remnant (SNR) shocks and then…
The positron fraction observed by PAMELA and other experiments up to ~ 100 GeV is analyzed in terms of models of cosmic-ray propagation. It is shown that generically we expect the positron fraction to reach ~ 0.6 at energies of several TeV,…
The flux of cosmic-ray high-energy positrons has recently been measured by AMS with unprecedented precision. This flux is well above the expectation from secondary positrons made by the observed fluxes of nuclear cosmic rays impinging on…
The bulk of observed ultrahigh energy cosmic rays could be light or heavier elements, and originate from an either steady or transient population of sources. This leaves us with four general categories of sources. Energetic requirements set…
Recent data reported by the PAMELA and ATIC experiments, as well as cosmic ray lepton results from FERMI and H.E.S.S. collaborations sparked a series of papers explaining these results either by contributions of electron positron pairs to…
The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above $10^{19}\,$eV as reported by the Auger…
The Alpha Magnetic Spectrometer (AMS-02) has provided unprecedented precision measurements of the electron and positron cosmic-ray fluxes and the positron fraction spectrum. At the higher energies, sources as energetic local pulsars, may…
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…
The antiproton flux measured by PAMELA experiment might have originated from Galactic sources of cosmic rays. These antiprotons are expected to be produced in the interactions of cosmic ray protons and nuclei with cold protons. Gamma rays…