相关论文: On leptonic models for blazars in the Fermi era
(Abridged) We have conducted a detailed investigation of the broad-band spectral properties of the \gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with…
Excess of gamma rays with a spherical morphology around the Galactic center (GC) observed in the Fermi large area telescope (LAT) data is one of the most intriguing features in the gamma-ray sky. The excess has been interpreted by…
An excess of gamma rays at GeV energies has been detected in the Fermi-LAT data. This signal comes from a narrow region around the Galactic Center and has been interpreted as possible evidence for light (30 GeV) dark matter particles.…
The origin of gamma-ray flares observed from blazars is one of the major mysteries in jet physics. We have attempted to address this problem following a novel spectral energy distribution (SED) fitting technique that explored the flaring…
Fast radio bursts (FRBs) are one of the most exciting new mysteries of astrophysics. Their origin is still unknown, but recent observations seem to link them to soft gamma repeaters and, in particular, to magnetar giant flares (MGFs). The…
The emission of very-high-energy photons (VHE, E>100 GeV$) in blazars is closely connected to the production of ultra-relativistic particles and the role of these gamma-ray sources as cosmic particle accelerators. This work focuses on a…
Blazars are a small fraction of all extragalactic sources but, unlike other objects, they are strong emitters across the entire electromagnetic spectrum. In this study we have conducted a detailed investigation of the broad-band spectral…
We consider gamma-ray burst models where the radiation is dominated by a photospheric region providing the MeV Band spectrum, and an external shock region responsible for the GeV radiation via inverse Compton scattering. We parametrize the…
Analysis of gamma-ray emission from the supernova remnant G78.2+2.1 ($\gamma$ Cygni) with 7.2 years of cumulative data from the Fermi-LAT telescope shows a distinct hard, bright and extended component to the north of the shell coincident…
We discuss three topics: (i) the dynamics of afterglow jet breaks; (ii) the origin of Fermi-LAT photons; (iii) the electromagnetic model of short GRBs
We present an extensive analysis of the multi-wavelength data of the low-synchrotron-peaked BL Lac object CGRaBS J0211+1051, which has been gathered over more than ten years with many observatories. Two major gamma-ray flares have been…
Context. More than one hundred GeV pulsars have been detected up to now by the LAT telescope on the Fermi gamma-ray observatory, showing peak energies around a few GeV. Current modelling proposes that the high energy emission comes from…
The Fermi Gamma-ray Space Telescope, as an all-sky survey and monitoring mission, is producing daily/weekly sampled gamma-ray light curves for dozens of blazars and other high-energy sources. Highlights on MeV-GeV gamma-ray variability…
We investigate hadronic and leptonic scenarios for the GeV--TeV gamma-ray emission from jets of the microquasar SS 433. The emission region of the TeV photons coincides with the X-ray knots, where electrons are efficiently accelerated. On…
In recent years, blazar surveys at radio and X-ray energies have greatly increased our understanding of this type of active galaxy. The combination of multi-wavelength data has shown that blazars follow a well defined sequence in terms of…
The highest-energy blazars exhibit non-thermal radiation extending beyond 1 TeV with high luminosities and strong variabilities, indicating extreme particle acceleration in their relativistic jets. The gamma-ray spectra of blazars contain…
This is the first of a series of papers aimed at characterizing the populations detected in the high-latitude sky of the {\it Fermi}-LAT survey. In this work we focus on the intrinsic spectral and flux properties of the source sample. We…
Recent observations of VER J2227+608 reveal a broken power $\gamma$-ray spectrum with the spectral index increasing from $\sim 1.8$ in the GeV energy range to $\sim 2.3$ in the TeV range. Such a spectral break can be attributed to radiative…
It is well-known that the $\gamma$-ray emission in blazars originate in the relativistic jet pointed at the observers. However, it is not clear whether the exact location of the GeV emission is less than a pc from the central engine, such…
Blazars are active galactic nuclei with relativistic jets pointed almost directly at Earth. Blazars are characterized by strong, apparently stochastic flux variability at virtually all observed wavelengths and timescales, from minutes to…