Related papers: Seyfert 2 galaxies in the GeV band: jets and starb…
The IceCube Collaboration has recently reported compelling evidence of high-energy neutrino emission from NGC~1068, and also mild excesses for NGC 4151 and CGCG420-015, local Seyfert galaxies. This has increased the interest along neutrino…
Seyfert galaxies have traditionally been classified as radio-quiet active galactic nuclei. A proper consideration of the nuclear optical emission however proves that a majority of Seyferts are radio-loud. Kpc-scale radio lobes/bubbles are…
The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray…
Narrow-Line Seyfert 1 (NLS1) class of active galactic nuclei (AGNs) is generally radio-quiet, but a small percent of them are radio-loud. The recent discovery by Fermi/LAT of high-energy gamma-ray emission from 4 NLS1s proved the existence…
Recently the Fermi-LAT data have revealed two gamma-ray emitting bubble-shaped structures at the Galactic center. If the observed gamma rays have hadronic origin (collisions of accelerated protons), the bubbles must emit high energy…
Before the launch of the Fermi satellite only two classes of Active Galactic Nuclei (AGN) were known to generate relativistic jets and thus to emit up to the gamma-ray energy range: blazars and radio galaxies, both hosted in giant…
The Seyfert galaxy NGC 1275 is the central, dominant galaxy in the Perseus cluster of galaxies. NGC1275 is known as a powerful source of radio and X-ray emission. The well-known extragalactic object NGC 1275 has been observed by the SHALON…
MAGIC, a stereoscopic cherenkov telescope array, sensitive to gamma-rays between 50 GeV and several tens of TeV, is ideally suited to observe promising Fermi LAT sources with a hard \gamma-ray spectrum. Here we discuss the discovery of very…
Intrigued by recent high-energy study results for nearby galaxies with gamma-ray emission and in particular NGC~1068 that has been detected as a neutrino-emitting source by the IceCube Neutrino Observatory, we conduct detailed analysis of…
Seyfert galaxies are emerging as a promising source class of high-energy neutrinos. The Seyfert galaxies NGC 4151 and NGC 1068 have come up respectively as the most promising counterparts of a 3$\sigma$ and of a 4.2$\sigma$ neutrino…
We examine 288 GRBs detected by the Fermi Gamma-ray Space Telescope's Gamma-ray Burst Monitor (GBM) that fell within the field-of-view of Fermi's Large Area Telescope (LAT) during the first 2.5 years of observations, which showed no…
We present a catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first three years of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of…
We report results on multiband observations from radio to gamma-rays of the two radio-loud narrow-line Seyfert 1 (NLSy1) galaxies PKS 2004-447 and J1548+3511. Both sources show a core-jet structure on parsec scale, while they are unresolved…
Statistical analyses are invaluable methods used to understand intrinsic emission processes and the unification of extragalactic radio sources. In this paper, we collected radio, X-ray and {\gamma}-ray data of blazars from the Fermi-LAT and…
We present deep images of the kpc-scale radio continuum emission in 14 edge-on galaxies (ten Seyfert and four starburst galaxies). Observations were taken with the VLA at 4.9~GHz (6~cm). The Seyfert galaxies were selected from a…
The very high energy (VHE; >100 GeV) source HESS J0632+057 has been recently confirmed as a \gamma-ray binary, a subclass of the high mass X-ray binary (HMXB) population, through the detection of an orbital period of 321 days. We performed…
We present our recent spectrophotometric results of the infrared luminous Seyfert 2 galaxy NGC 7679. We find compelling evidence of the presence of a recent nuclear starburst, revealed by the observations of a) the spectral features of high…
We present a catalog of sources detected above 50 GeV by the {\it Fermi}-Large Area Telescope (LAT) in 80 months of data. The newly delivered Pass 8 event-level analysis allows the detection and characterization of sources in the 50 GeV--2…
The $BeppoSAX$ archive is currently the largest reservoir of high sensitivity simultaneous soft and hard-X ray data of Seyfert galaxies. From this database all the Seyfert galaxies (105 objects of which 43 are type I and 62 are type II)…
We report the detection of gamma-ray emission by the Fermi Large Area Telescope (Fermi-LAT) towards the young massive star cluster RCW 38 in the 1-500 GeV photon energy range. We found spatially extended GeV emission towards the direction…