The discovery of an expanding X-ray source in the HH 154 protostellar jet F. Favata, R. Bonito, G. Micela, M. Fridlund, S. Orlando, S. Sciortino and G. Peres A&A, 450 1 (2006) L17-L20 Published online: 03 April 2006 DOI: 10.1051/0004-6361:20065106