相关论文: TeV gamma-ray emission initiated by the population…
Using 16 years of data collected by Fermi Large Area Telescope and 1523 days of survey data from High Altitude Water Cherenkov (HAWC) Observatory, we discovered the long-sought second GeV-TeV connection towards the globular cluster (GC) UKS…
We estimate the TeV gamma-ray fluxes expected from the population of young pulsars in terms of the self-consistent time dependent hadronic-leptonic model for the high energy processes inside the pulsar wind nebulae. This radiation model…
Recent observations by the Fermi Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) have revealed globular clusters (GC) to be sources of high-energy (HE) and very-high-energy (VHE) gamma-rays. It has been…
The diffuse gamma-rays in the Galactic center region have been studied. We propose that there exists a population of millisecond pulsars (MSPs) in the Galactic Center, which will emit GeV gamma-rays through the synchrotron-curvature…
Globular clusters (GCs) are established emitters of high-energy (HE, 100 MeV<E<100 GeV) \gamma-ray radiation which could originate from the cumulative emission of the numerous millisecond pulsars (msPSRs) in the clusters' cores or from…
It has been proposed that a large population of unresolved millisecond pulsars (MSPs) could potentially account for the excess of GeV-scale gamma-rays observed from the region surrounding the Galactic Center. The viability of this scenario…
The recent Fermi detection of the globular cluster (GC) 47 Tucanae highlighted the importance of modeling collective gamma-ray emission of millisecond pulsars (MSPs) in GCs. Steady flux from such populations is also expected in the very…
Globular clusters (GCs) are astronomical tapestries embroidered with an abundance of exotic stellar-type objects. Their high age promises a rich harvest of evolved stellar products, while the deep potential wells and high mass densities at…
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…
Over the last few years, the data obtained using the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope has provided new insights on high-energy processes in globular clusters, particularly those involving compact objects…
Recently, diffuse and extended sources in TeV gamma-rays as well as in X-rays have been detected in the direction of the Galactic globular cluster (GC) Terzan 5. Remarkably, this is among the brightest GCs detected in the GeV regime. The…
The GeV-scale gamma-ray excess observed from the region surrounding the Galactic Center has been interpreted as either the products of annihilating dark matter particles, or as the emission from a large population of faint and…
A cluster of galaxies is a huge system bounded by gravitation, and cosmic rays are thought to be confined in the system, thus it should contain much non-thermal components. Many theories predict significant gamma-ray emission that could be…
Gamma-ray observations have shown pulsars to be efficient converters of rotational energy into GeV photons and it is of wide-ranging interest to determine their contribution to the gamma-ray background. We arrive at flux predictions from…
Young massive star clusters (YMSCs) can produce gamma rays in the very-high-energy (VHE, E>100 GeV) range and have been proposed as sources that can accelerate cosmic rays up to PeV energies. Observations with current instruments have lead…
The dominant mechanisms underlying high-energy $\gamma$-ray emission from galaxies vary by galaxy type. In starbursts, a major contribution comes from neutral pion decay. This is driven by interactions between interstellar gas and hadronic…
We present results from an emission code that assumes millisecond pulsars (MSPs) to be sources of relativistic particles in globular clusters (GCs) and models the resulting spectral energy distribution (SED) of Galactic GCs due to these…
Galaxy clusters might be sources of TeV gamma rays emitted by high-energy protons and electrons accelerated by large scale structure formation shocks, galactic winds, or active galactic nuclei. Furthermore, gamma rays may be produced in…
Measurements of the nearby pulsars Geminga and B0656+14 by the HAWC and Milagro telescopes have revealed the presence of bright TeV-emitting halos surrounding these objects. If young and middle-aged pulsars near the Galactic Center transfer…
Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly $\pm$20 degrees in latitude. The leading theory postulates that this GeV excess is…