Related papers: TeV Blazars and Cosmic Infrared Background Radiati…

Diffusive TeV gamma-ray emissions have been recently discovered extending beyond the pulsar wind nebulae of a few middle-aged pulsars, implying that energetic electron/positron pairs are escaping from the pulsar wind nebulae and radiating…

This review paper discusses the past and present observations of gamma-ray blazars with both space and ground-based gamma-ray telescopes (such as EGRET and current TeV telescopes), and with the VLBA. I also discuss the more sensitive…

Important observational results have been recently reported on the angular distributions of cosmic rays at all energies, calling into question the perception of cosmic rays a decade ago. These results together with their in-progress…

The latest determination of the extragalactic gamma-ray background (EGRB) radiation by Fermi is compared with the theoretical prediction of the blazar component by Inoue & Totani (2009; hereafter IT09). The Fermi EGRB spectrum is in…

The magnetic fields that emerge from beneath the solar surface and permeate the solar atmosphere are the key drivers of space weather and, thus, understanding them is important to human society. Direct observations, used to measure magnetic…

In addition to its relevant astrophysical and cosmological significance, the Extragalactic Background Light (EBL) is a fundamental source of opacity for cosmic high energy photons, as well as a limitation for the propagation of high-energy…

The field of high-energy neutrino astronomy is undergoing a rapid evolution. After the discovery of a diffuse flux of astrophysical TeV-PeV neutrinos in 2013, the IceCube observatory has recently found first compelling evidence for neutrino…

Analyses of TeV-PeV cosmic ray (CR) diffusion around their sources usually assume either isotropic diffusion or anisotropic diffusion due to the regular Galactic magnetic field. We show that none of them are adequate on distances smaller…

Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to…

A recent progress in the study of $\gamma$-ray jets is reviewed, with a focus on some theoretical interpretations of the VHE emission from M87, and possibly other misaligned blazars; the connection betwe en the GeV breaks exhibited by…

This is a report on the findings of the extragalactic science working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper was commissioned by the American Physical Society, and the full white paper…

In this paper, I will take a synoptic approach to determining the intergalactic infrared radiation field (IIRF). This approach draws on both the multi-TeV gamma-ray observations and the infrared background observations and relates them via…

Blazars are the most violent steady/recurrent sources of high-energy gamma-ray emission in the known Universe. They are prominent emitters of electromagnetic radiation throughout the entire electromagnetic spectrum. The observable radiation…

The recent and brightest GRB 221009A observed by LHAASO marked the first detection of the onset of TeV afterglow, with a total of 7 GRBs exhibiting very high energy (VHE) afterglow radiation. However, consensus on VHE radiation of GRBs is…

In recent years, exciting developments have taken place in the identification of the role of cosmic rays in star-forming environments. Observations from radio to infrared wavelengths and theoretical modelling have shown that low-energy…

Active galactic nuclei (AGN) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary gamma rays produced along the line of sight by the interactions of…

Studying the propagation of gamma rays on cosmological distances encompasses a variety of scientific fields, focusing on diffuse radiation fields such as the extragalactic background light, on the probe of the magnetism of the Universe on…

The last years have seen a revolution in ground-based gamma-ray detectors. We can now detect the spectra of nearby TeV blazars like Mrk 421 and 501 out to approximately 20 TeV, and during the strongest flares, we can now follow fluctuations…

The hunt for cosmic TeV particle accelerators is prospering through Imaging Atmospheric Cerenkov Telescopes. We face challenges such as low light levels and MHz trigger rates, and the need to distinguish between particle air showers…

Thanks to the Fermi gamma-ray satellite and the current Imaging Atmospheric Cherenkov Telescopes, radio galaxies have arisen as a new class of high- and very-high energy emitters. The favourable orientation of their jets makes radio…