X-rays from jet-driving protostars and T Tauri stars M. Güdel, A. Telleschi, M. Audard, S. L. Skinner, K. R. Briggs, F. Palla and C. Dougados A&A, 468 2 (2007) 515-528 Published online: 11 October 2006 DOI: 10.1051/0004-6361:20065736