相关论文: Gamma-rays from millisecond pulsar population with…
We study the gamma-ray emissions from an outer-magnetospheric potential gap around a rotating neutron star. Migratory electrons and positrons are accelerated by the electric field in the gap to radiate copious gamma-rays via curvature…
Galactic cosmic rays reach energies of at least a few Peta-electronvolts (1 PeV =$10^\mathbf{15}$ electron volts). This implies our Galaxy contains PeV accelerators (PeVatrons), but all proposed models of Galactic cosmic-ray accelerators…
We present spectra of pulsed gamma-ray emission expected from millisecond pulsars within the framework of polar-cap models. The spectra are a superposition of three components due to curvature (CR), synchrotron (SR), and Compton…
The Galactic Center (GC) is potentially hosting the largest indirect signal from particle dark matter (DM), which in many well-motivated models would produce gamma rays as their final states. However, this region has often been dismissed…
The large-scale diffuse $\gamma-$ray flux observed by Fermi-LAT in the 1-100 GeV energy range, parameterized as $\propto E^{-\Gamma}$, has a spectral index $\Gamma$ that depends on the distance from the Galactic center. This feature, if…
Globular clusters (GCs) are evolved stellar systems containing entire populations of millisecond pulsars (MSPs), which are efficient gamma-ray emitters. Observations of this emission can be used as a powerful tool to explore the dynamical…
Observations by the Fermi Large Area Telescope of gamma-ray millisecond pulsar light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may be a primary source…
Recently, gamma-ray emission at TeV energies has been detected from the starburst galaxies NGC253 (Acero et al., 2009) and M82 (Acciari et al., 2009. It has been claimed that pion production due to cosmic rays accelerated in supernova…
Recent results from the HESS gamma ray telescope have shown the presence of both a diffuse, extended, flux of gamma rays above ~0.4 TeV and discrete sources in and near the Galactic Centre. Here, we put forward a possible explanation in…
Recent {\gamma}-ray observations suggest that the {\gamma}-ray millisecond pulsar (MSP) population is separated into two sub-classes with respect to the pair multiplicity. Here, we calculate the cosmic ray electron/positron spectra from…
Stochastic acceleration of electrons interacting resonantly with a turbulent magnetic field in a small accretion torus appears to be the likely mechanism responsible for much of Sagittarius A*'s millimeter and shorter wavelength spectrum.…
The GeV-TeV {\gamma}-ray emission is observed from the direction of the source Sgr A^*, which is identified with the SMBH in the centre of our Galaxy. According to some models this {\gamma}-ray emission might originate in the very compact,…
We consider a possibility of identification of sources of cosmic rays (CR) of the energy above 1 TeV via observation of degree-scale extended gamma-ray emission which traces the locations of recent sources in the Galaxy. Such emission in…
Recent progress in pushing the sensitivity of the Imaging Atmospheric Cherenkov Technique into the 10 mCrab regime has enabled first sensitive observations of the innermost few 100 pc of the Milky Way in Very High Energy (VHE; >100 GeV)…
Millisecond pulsars occur abundantly in globular clusters. They are expected to be responsible for several spectral components in the radio through gamma-ray waveband (e.g., involving synchrotron and inverse Compton emission), as have been…
Intriguing sub-TeV tails in the pulsed $\gamma$-ray emission from the Crab pulsar have been recently discovered by the MAGIC and VERITAS Collaborations. They were not clearly predicted by any pulsar model. It is at present argued that this…
Accreting black holes are believed to be sites of possible particle acceleration with favorable conditions also for effective gamma-ray production. However, because of photon-photon pair production, only low energy (MeV) gamma-rays can…
Massive black holes in active galaxies are immersed in huge concentrations of late type stars in the galactic bulges and also early type massive stars in the nuclear stellar clusters which are additionally surrounded by quasi-spherical…
Cosmic rays are important probe of a number of fundamental physical problems such as the acceleration of high and very high energy particles in extreme astrophysical environments. The Galactic center is widely anticipated to be an important…
Recently, two nearby prominent starburst galaxies, M82 and NGC253, have been detected as point-like sources with gamma-ray telescopes at TeV energies [1] [2]. It has been claimed that these detections show that the cosmic ray intensity in…