Related papers: Diffuse emission from stochastic sources
We revisit the signatures from collisions of cosmic-rays on sub-GeV dark matter (DM) in the Milky Way. In addition to the upscattered DM component that can be probed by existing DM and neutrino experiments widely discussed, we examine the…
SNRs are likely to be significant sources of Galactic cosmic rays up to the knee. They produce gamma rays in the very-high-energy (E>100 GeV) range mainly via two mechanisms: hadronic interactions of accelerated protons with the…
The field of TeV gamma-ray astronomy is reviewed with emphasis on its relation to the origin of cosmic rays. The discovery of TeV photons from supernova remnants and active galaxies has provided the first direct observational link between…
Observations of the Milky Way at TeV-PeV energies reveal a bright diffuse flux of hadronic cosmic rays and also bright point sources of gamma rays. If the gamma-ray sources are hadronic cosmic-ray accelerators, then they must also be…
GeV and TeV emission from the forward shocks of supernova remnants (SNRs) indicates that they are capable particle accelerators, making them promising sources of Galactic cosmic rays (CRs). However, it remains uncertain whether this…
The recent IceCube publication claims the observation of cosmic neutrinos with energies down to $\sim 10$ TeV, reinforcing the growing evidence that the neutrino flux in the 10-100 TeV range is unexpectedly large. Any conceivable source of…
The observed very high energy spectra of distant blazars are well described by secondary gamma rays produced in line-of-sight interactions of cosmic rays with background photons. In the absence of the cosmic-ray contribution, one would not…
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…
High-energy neutrinos are traditionally regarded as unambiguous signatures of hadronic cosmic rays in astrophysical environments. Here we show that TeV neutrinos can instead be produced by energetic electrons through purely electromagnetic…
The LHAASO collaboration has recently released the spectrum and the angular distribution of the gamma-ray Galactic diffuse emission from 1 TeV to 1 PeV measured with the Kilometer-2 Array (KM2A) and the Water Cherenkov Detector Array…
Using the cosmic ray (CR) data available in the energy interval $(10 - 2 \times 10^{7})$ GeV/particle, we have calculated the profile of the primary $\gamma$-ray spectrum produced by the interaction of these CR with thermal nuclei of the…
Possible existence of extragalactic ultra-high energy cosmic ray sources giving a very small particle flux on the Earth is considered. Accretion discs around supermassive black holes where particles are accelerated in electric fields are…
The Galactic diffuse emission (GDE) is formed when cosmic rays leave the sources where they were accelerated, diffusively propagate in the Galactic magnetic field, and interact with the interstellar medium and interstellar radiation field.…
Cosmic rays travel throughout the Galaxy, leaving traces from radio to ultra-high-energy gamma rays due to interactions with the interstellar gas, radiation field and magnetic field. Therefore, it is necessary to utilize multi-wavelength…
The origin of the X-ray emission from the central region of the Galaxy has remained a mystery, despite extensive study over the past two decades. A fundamental question is the relative contribution of the point-source and diffuse components…
Multi-messenger high-energy astrophysics has currently achieved the potential to unravel the origin of cosmic rays and how sources accelerate them, their relation to the diffuse radiation in the extra-galactic space, and their role to forge…
[Abdriged] The origin of the diffuse hard X-ray (2 - 10 keV) emission from starburst galaxies is a long-standing problem. We suggest that synchrotron emission of 10 - 100 TeV electrons and positrons (e+/-) can contribute to this emission,…
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…
The distances that galactic cosmic ray electrons and positrons can travel are severely limited by energy losses to at most a few kiloparsec, thereby rendering the local spectrum very sensitive to the exact distribution of sources in our…
Massive protostars have associated bipolar outflows with velocities of hundreds of km s$^{-1}$. Such outflows can produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. We aim at…