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Related papers: Mirage Sources and Large TeV Halo-Pulsar Offsets: …

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Pulsar halos are a recently identified class of TeV $\gamma$-ray sources, offering valuable insights into the evolution of pulsar systems at the highest energies. However, only a handful of such sources have been detected so far, making…

High Energy Astrophysical Phenomena · Physics 2025-10-06 Tina Wach , Alison M. W. Mitchell

Observations are consistent with a significant fraction of heavy nuclei in the cosmic ray flux above a few times 10^19 eV. Such nuclei can be deflected considerably in the Galactic magnetic field, with important implications for the search…

High Energy Astrophysical Phenomena · Physics 2014-11-21 G. Giacinti , M. Kachelriess , D. V. Semikoz , G. Sigl

The recent measurement by LHAASO of gamma-ray emission extending up to 100s of TeV from multiple Galactic sources represents a major observational step forward in the search for the origin of the Galactic cosmic rays. The burning question…

High Energy Astrophysical Phenomena · Physics 2022-03-30 M. Breuhaus , B. Reville , J. A. Hinton

We investigate the dependence of composition, spectrum and angular distributions of ultra-high energy cosmic rays above 10^19 eV from individual sources on their magnetization. We find that, especially for sources within a few megaparsecs…

Astrophysics · Physics 2009-11-10 Guenter Sigl

Despite significant progress over more than 100 years, no accelerator has been unambiguously identified as the source of the locally measured flux of cosmic rays. High-energy electrons and positrons are of particular importance in the…

High Energy Astrophysical Phenomena · Physics 2018-11-30 Philipp Mertsch

Recent gamma-ray observations have detected photons up to energies of a few PeV. These highly energetic gamma rays are emitted by the most powerful sources in the Galaxy. Propagating over astrophysical distances, gamma rays might interact…

High Energy Astrophysical Phenomena · Physics 2025-04-18 Gaetano Di Marco , Rafael Alves Batista , Miguel Ángel Sánchez-Conde

Diffuse gamma-ray emission (DGE) has been discovered over the Galactic disk in the energy range from sub-GeV to sub-PeV. While it is believed to be dominated by the pionic emission of cosmic ray (CR) hadrons via interactions with…

High Energy Astrophysical Phenomena · Physics 2023-05-18 Kai Yan , Ruo-Yu Liu

We present the result of a search of the Milagro sky map for spatial correlations with sources from a subset of the recent Fermi Bright Source List (BSL). The BSL consists of the 205 most significant sources detected above 100 MeV by the…

TeV halos are extended very-high-energy (VHE; 0.1-100 TeV) gamma-ray emission around middle-aged pulsars. So far they have only been found around isolated pulsars, but it has been suggested that they may also be powered by millisecond…

Extended regions of very high energy $\gamma$-ray emission associated with middle-aged pulsars have been found by $\gamma$-ray observatories. These regions, called TeV halos or pulsar halos, are thought to be created when energetic…

High Energy Astrophysical Phenomena · Physics 2025-04-14 David Guevel , Kim L Page , Kaya Mori , Amy Lien , Ke Fang

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…

Astrophysics · Physics 2009-10-30 G. A. Medina Tanco , E. M. de Gouveia Dal Pino

In this paper we study the formation of giant electrons-positron pair halos around the powerful high energy extragalactic sources. We investigate the dependence of radiation of pair halos, in particular the spectral and angular…

High Energy Astrophysical Phenomena · Physics 2015-05-13 A. Eungwanichayapant , F. A. Aharonian

In this work, we present detailed simulations for propagation of ultra-high energy (UHE) heavy nuclei, with E > 60 EeV, within recent Galactic Magnetic Field (GMF) models. We investigate the impacts of the regular and turbulent components…

High Energy Astrophysical Phenomena · Physics 2015-05-30 G. Giacinti , M. Kachelriess , D. V. Semikoz , G. Sigl

The HAWC Gamma-Ray Observatory has reported the discovery of TeV gamma-ray emission extending several degrees around the positions of Geminga and B0656+14 pulsars. Assuming these gamma rays are produced by inverse Compton scattering off…

High Energy Astrophysical Phenomena · Physics 2019-08-13 F. Salesa Greus , S. Casanova , B. Dingus , R. Lopez-Coto , H. Zhou

The study of propagation of Ultra High Energy Cosmic Rays (UHECR) is a key step in order to unveil the secret of their origin. Up to now it was considered only the influence of the galactic and the extragalactic magnetic fields. In this…

Astrophysics · Physics 2009-11-11 Pascal Chardonnet , Alvise Mattei

Ultrahigh energy protons and nuclei from extragalactic cosmic ray sources initiate intergalactic electromagnetic cascades, resulting in observable fluxes of $\gamma$-rays in the GeV-TeV energy domain. The total spectrum of such cascade…

High Energy Astrophysical Phenomena · Physics 2021-07-21 E. V. Khalikov , T. A. Dzhatdoev

The H.E.S.S. telescope has recently detected the total electron-plus-positron ($e^+e^-$) flux up to 40 TeV, finding it to be a featureless and steeply-falling power-law above 1 TeV. This result is in stark tension with standard one-zone…

High Energy Astrophysical Phenomena · Physics 2025-03-25 Isabelle John , Tim Linden

The deflection of extragalactic ultra-high energy protons (E > 4E19 eV) travelling to our galaxy is studied assuming that visible matter traces both, the sources of the particles and the intergalactic magnetic field. The reversal scale and…

Astrophysics · Physics 2007-05-23 Gustavo A. Medina Tanco

Simulations of Galactic CR transport were performed with the software GALPROP, with the resulting gamma-ray flux calculated up to the PeV regime. The impact of altering parameters such as the number and distribution of CR sources, the…

High Energy Astrophysical Phenomena · Physics 2025-04-29 Peter Marinos

Ultra-high energy cosmic ray protons accelerated in astrophysical objects produce secondary electromagnetic cascades during propagation in the cosmic microwave and infrared backgrounds. We show that such cascades can contribute between ~1%…

Astrophysics · Physics 2014-11-18 Oleg E. Kalashev , Dmitry V. Semikoz , Guenter Sigl