4U 0115 + 63: phase lags and cyclotron resonant scattering C. Ferrigno, M. Falanga, E. Bozzo, P. A. Becker, D. Klochkov and A. Santangelo A&A, 532 (2011) A76 Published online: 26 July 2011 DOI: 10.1051/0004-6361/201116826