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		| Paper: | 
		Fermi/LAT Discovery of Gamma-Ray Emission from a Relativistic Jet in the Narrow-Line Seyfert 1 Quasar PMN J0948+0022 | 
	 
	
		| Volume: | 
		427, Accretion and Ejection in AGN: a Global View | 
	 
	
		| Page: | 
		243 | 
	 
	
		| Authors: | 
		Foschini, L., Fermi/LAT collaboration; Ghisellini, G.; Maraschi, L.; Tavecchio, F.; Angelakis, E. | 
	 
	
	
		| Abstract: | 
		We report the discovery by the Large Area Telescope (LAT) onboard the  Fermi Gamma-ray Space Telescope of high-energy gamma-ray emission from the peculiar quasar PMN J0948+0022 (z=0.585±0.001). Contrary to the expectations, the optical spectrum of this quasar shows only narrow lines [FWHM(Hβ) ∼ 1500 km/s] and the typical characteristics of narrow-line Seyfert 1 type galaxies. However, the strong radio emission and the flat spectrum suggest the presence of a relativistic jet, which can now be confirmed by the detection of MeV-GeV photons. PMN J0948+0022 is therefore the first radio-loud narrow-line Seyfert 1 quasar to be detected at gamma-rays and the third type of γ–ray emitting AGN, after blazars and radiogalaxies. | 
	 
	
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