Tracing high energy radiation with molecular lines near deeply embedded protostars P. Stäuber, A. O. Benz, J. K. Jørgensen, E. F. van Dishoeck, S. D. Doty and F. F. S. van der Tak A&A, 466 3 (2007) 977-988 Published online: 24 April 2007 DOI: 10.1051/0004-6361:20065762