Relativistic Jets in Gamma-Ray-Emitting Narrow-Line Seyfert 1 Galaxies
Before the launch of the Fermi Gamma-ray Space Telescope satellite only two classes of active galactic nuclei (AGN) were known to generate relativistic jets and thus to emit up to the γ -ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies.The discovery by the Large Area Telescope (LAT) on-board the Fermi sate