Related papers: Inverse Compton gamma-ray models for remnants of G…
Gamma-ray line emission is a direct probe of the nucleosynthesis that occurs in Type Ia supernovae. In this work we describe the wealth of information obtainable from observations of this emission. Advanced Compton telescope designs are…
Supernova remnants have long been suggested as a class of potential counterparts to unidentified gamma-ray sources. The mechanisms by which such gamma-rays can arise may include emission from a pulsar associated with a remnant, or a variety…
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…
The recent observations of GW170817 and its electromagnetic (EM) counterparts show that double neutron star mergers could lead to rich and bright EM emissions. Recent numerical simulations suggest that neutron star and neutron star/black…
There is now compelling evidence of a link between long-duration gamma-ray bursts (GRBs) and Type Ib/c supernovae (SNe). These core-collapse explosions are conjectured to radiate an anisotropic, beamed component associated with a…
The emission mechanism of the gamma-ray bursts (GRBs) is still a matter of debates. The standard synchrotron energy spectrum of cooling electrons F_E ~ E^{-1/2} is much too soft to account for the majority of the observed spectral slopes.…
The contribution of Source Cosmic Rays (SCRs), accelerated and still confined in Supernova Remnants (SNRs), to the diffuse high energy \gr emission above 1 GeV from the Galactic disk is studied. The \grs produced by the SCRs have a much…
Several young supernova remnants (SNRs) have recently been detected in the high-energy and very-high-energy gamma-ray domains. As exemplified by RX J1713.7-3946, the nature of this emission has been hotly debated, and direct evidence for…
The X-ray emission from the knots of the kilo-parsec scale jet of active galactic nuclei (AGN) suggests the high energy emission process is different from the radio/optical counterpart. Interpretation based on the Inverse Compton scattering…
Relativistic electrons are an essential component in many astrophysical sources, and their radiation may dominate the high-energy bands. Inverse Compton (IC) emission is the radiation mechanism that plays the most important role in these…
We aim to test the plausibility of a theoretical framework in which the gamma-ray emission detected from supernova remnants may be of hadronic origin, i.e., due to the decay of neutral pions produced in nuclear collisions involving…
We discovered independently the shell-type supernova remnant G12.82-0.02, recently reported by Brogan et al. (2005), which is coincident with the unidentified TeV gamma-ray source revealed in the HESS survey of the Galactic plane.…
The extended high-energy gamma-ray (>100 MeV) emission which occurs well after the prompt gamma-ray bursts (GRBs) is usually explained as the afterglow synchrotron radiation. Here we report the analysis of the Fermi Large Area Telescope…
It is shown that inverse Compton gamma-rays from electrons accelerated in large scale structure formation shocks can be crucially affected by non-gravitational effects such as radiative cooling and galaxy formation, with corresponding…
Recent Fermi and VERITAS observations of the prototypical Type Ia supernova remnant (SNR) Tycho have discovered gamma-rays with energies E in the range from ~0.4 GeV to 10 TeV. Crucial for the theory of Galactic cosmic-ray origin is whether…
We have analyzed XMM-Newton, Chandra, and Suzaku observations of Kepler's supernova remnant (SNR) to investigate the properties of both the SN ejecta and the circumstellar medium (CSM). For comparison, we have also analyzed two…
Millisecond pulsars are very likely the main source of gamma-ray emission from globular clusters. However, the relative contributions of two separate emission processes--curvature radiation from millisecond pulsar magnetospheres vs. inverse…
Recent simulations have shown that asymmetries in the ejecta distribution of supernova remnants (SNRs) may be a reflection of asymmetries left over from the initial supernova explosion. Thus, SNR studies provide a vital means for testing…
In addition to gamma-rays, dark matter annihilation products can include energetic electrons which inverse Compton scatter with the cosmic microwave background to produce a diffuse extragalactic background of gamma-rays and X-rays. In…
Free electrons deplete photons from type Ia supernovae through the (inverse) Compton scattering. This Compton dimming increases with redshift and reaches 0.004 mag at $z=1$ and 0.01 mag at $z=2$. Although far from sufficient to invalidate…