Related papers: Source population synthesis and the Galactic diffu…
We study the $\gamma$-ray emission from the pulsar magnetosphere based on outer gap models, and the TeV radiation from pulsar wind nebulae (PWNe) through inverse Compton scattering using a one-zone model. We showed previously that GeV…
In studies of cosmic-ray (CR) propagation and diffuse continuum gamma-ray emission from the Galaxy it has usually been assumed that the source function can be taken as smooth and time-independent. However, especially for electrons at high…
The ~70 unidentified sources of the EGRET sky survey may be one of its most important legacies. The identification of these sources at other wavelengths is critical to understanding their nature. Many have flat spectra out to 10 GeV which,…
The stellar population synthesis in unresolved composite objects is a very tricky problem. Indeed, it is a degenerate problem since many parameters affect the observables. The stellar population synthesis issue thus deserves a deep and…
The all-sky survey in high-energy gamma rays (E$>$30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma-Ray Observatory provides a unique opportunity to examine in detail the diffuse gamma-ray…
At very high energies (VHE), the emission of $\gamma$ rays is dominated by discrete sources. Due to the limited resolution and sensitivity of current-generation instruments, only a small fraction of the total Galactic population of VHE…
We studied the problematic of uncertainties in the diffuse gamma radiation apparent in stacking analysis of EGRET data at low Galactic latitudes. Subsequently, we co-added maps of counts, exposure and diffuse background, and residuals, in…
Stellar population studies of early-type galaxies (ETGs) based on their optical stellar continuum suggest that these are quiescent systems. However, emission lines and ultraviolet photometry reveal a diverse population. We use a new version…
Inverse Compton scattering appears to play a more important role in the diffuse Galactic continuum emission than previously thought, from MeV to GeV energies. We compare models having a large inverse Compton component with EGRET data, and…
The GALPROP model for cosmic-ray propagation is able to make explicit predictions for the distribution of galactic diffuse gamma-rays. We compare different propagation models with gamma-ray spectra measured by EGRET for various regions of…
Population studies of unidentified EGRET sources suggest that there exist at least three different populations of galactic gamma-ray sources. One of these populations is formed by young objects distributed along the galactic plane with a…
Over half of GeV gamma-ray sources observed by the EGRET experiment have not yet been identified as known astronomical objects. There is an isotropic component of such unidentified sources, whose number is about 60 in the whole sky. Here we…
Detection of point sources in images is a fundamental operation in astrophysics, and is crucial for constraining population models of the underlying point sources or characterizing the background emission. Standard techniques fall short in…
We use the GALPROP model for cosmic-ray propagation to obtain a new estimate of the Galactic component of gamma rays, and show that away from the Galactic plane it gives an accurate prediction of the observed EGRET intensities in the energy…
The origin of the inner Galactic emission, measured by COMPTEL with a flux of $\sim 10^{-2} ~{\rm MeV~ cm}^{-2}~ {\rm s}^{-1}~ {\rm sr}^{-1}$ in the 1-30 MeV energy range from the inner Galactic region, has remained unsettled since its…
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…
If the mysterious Fermi-LAT GeV gamma-ray excess is due to an unresolved population of millisecond pulsars (MSP) in the Galactic bulge, one expects this very same population to shine in X rays. For the first time, we address the question of…
The diffuse Galactic $\gamma$-ray emission (DGE) provides a valuable probe for investigating the cosmic ray propagation and interactions within our Galactic environment. Recent observations have demonstrated systematic excesses of DGE…
A new population of millisecond pulsars is a long-standing proposed explanation for the excess of GeV-scale gamma rays emanating from the region surrounding the center of the Milky Way (the "Galactic Center excess"). We examine several…
In a recent paper, Romero et al. (1999) have presented the results of a positional correlation analysis of the low-latitude unidentified gamma-ray sources in the Third EGRET catalog with complete lists of galactic objects like supernova…