Related papers: Are pulsar halos rare ?
We report on the X-ray properties of four rotation-powered pulsars with characteristic ages in the range 0.3-5 Myr, derived from the analysis of XMM-Newton archival observations. We found convincing evidence of thermal emission only in the…
We investigate the electron-positron pair cascade taking place in the magnetosphere of a rapidly rotating black hole. Because of the spacetime frame dragging, the Goldreich-Julian charge density changes sign in the vicinity of the event…
Observations of our Galaxy at very-high and ultra-high photon energies have revealed a rich population of sources, many of which have significant angular extension and/or are positionally coincident with energetic pulsars. We assessed…
We present new, high frequency radio observations of the merging galaxy clusters PLCK G287.0+32.9, Abell 2744, and Bullet. These clusters are known to host $\sim$Mpc scale sources, known as radio halos, which are formed by the acceleration…
We investigate the conditions required for the production of electron-positron pairs above a pulsar polar cap (PC) and the influence of pair production on the energetics of the primary particle acceleration. Assuming space-charge limited…
The Vela and Geminga pulsars are rotation powered neutron stars, which have been identified in various spectral domains, from the near-infrared to hard $\gamma$-rays. In the near-infrared they exhibit tentative emission excesses, as…
Extinct radio pulsars, in which stationary, self-sustaining generation of a relativistic electron-positron plasma becomes impossible when rotation brakes down, can be sources of a subrelativistic flux of positrons and electrons. We assume…
It is well established that phenomenological two-zone diffusion models of the galactic halo can very well reproduce cosmic-ray nuclear data and the observed antiproton flux. Here, we consider lepton propagation in such models and compute…
We present results of Compton Gamma-Ray Observatory EGRET observations of the unidentified high-energy gamma-ray sources 2EG J1049-5847 (GEV J1047-5840, 3EG J1048-5840) and 2EG J1103-6106 (3EG J1102-6103). These sources are spatially…
We search for the gamma-ray counterparts of stellar-mass black holes using long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon, by applying the pulsar…
Recent observations of the diffuse Galactic gamma-ray emission by the Fermi-LAT satellite have shown significant deviations from models which assume the same diffusion properties for cosmic rays (CR) throughout the Galaxy. We explore the…
We investigated the multiband emission from the pulsar binaries XSS J12270-4859, PSR J2039-5617, and PSR J2339-0533, which exhibit orbital modulation in the X-ray and gamma-ray bands. We constructed the sources' broadband spectral energy…
The Milky Way, the Andromeda galaxy, and Centaurus A host flattened distributions of satellite galaxies which exhibits coherent velocity trends indicative of rotation. Comparably extreme satellite structures are very rare in cosmological…
The HAWC Collaboration has observed gamma rays at energies above 56 TeV from a collection of nine sources. It has been suggested that this emission could be hadronic in nature, requiring that these systems accelerate cosmic-ray protons or…
We report the detection of an extended very-high-energy (VHE) gamma-ray source coincident with the location of middle-aged (62.4~\rm kyr) pulsar PSR J0248+6021, by using the LHAASO-WCDA data of live 796 days and LHAASO-KM2A data of live…
PSR B0355+54 is one of the handful of pulsars that has been observed with both Chandra and XMM-Newton. The analysis of the archival data has revealed the pulsar and a ~30 arcsec compact nebula surrounding it. XMM-Newton also has detected a…
Context: Very-high-energy (VHE; E>100 GeV) {\gamma}-ray emission from blazars inevitably gives rise to electron-positron pair production through the interaction of these {\gamma}-rays with the Extragalactic Background Light (EBL). Depending…
Gas rich sub-galactic halos with mass Mt <= 10^7.5 Msun, while incapable of forming stars due to lack of adequate coolants, contain a large fraction of baryonic mass at cosmological reionization. We show that the reionization of the…
Pulsars have long been studied in the electromagnetic spectrum. Their environments are rich in high-energy cosmic-ray electrons and positrons likely enriching the interstellar medium with such particles. In this work we use recent…
Most population studies of pulsars have hitherto focused on the disc of the Galaxy, the Galactic centre, globular clusters, and nearby galaxies. It is expected that pulsars, by virtue of their natal kicks, are also to be found in the…