XMM-Newton observations of the Lockman Hole IV: spectra of the brightest AGN S. Mateos, X. Barcons, F. J. Carrera, M. T. Ceballos, G. Hasinger, I. Lehmann, A. C. Fabian and A. Streblyanska A&A, 444 1 (2005) 79-99 Published online: 21 November 2005 DOI: 10.1051/0004-6361:20052881