The X-ray activity-rotation relation of T Tauri stars in Taurus-Auriga K. R. Briggs, M. Güdel, A. Telleschi, T. Preibisch, B. Stelzer, J. Bouvier, L. Rebull, M. Audard, L. Scelsi, G. Micela et al. (2 more) A&A, 468 2 (2007) 413-424 Published online: 22 January 2007 DOI: 10.1051/0004-6361:20066823