A correlation between the spectral and timing properties of AGN I. E. Papadakis, M. Sobolewska, P. Arevalo, A. Markowitz, I. M. Mc Hardy, L. Miller, J. N. Reeves and T. J. Turner A&A, 494 3 (2009) 905-913 Published online: 22 December 2008 DOI: 10.1051/0004-6361:200811005