Methanol maps of low-mass protostellar systems - I. The Serpens molecular coreL. E. Kristensen, E. F. van Dishoeck, T. A. van Kempen, H. M. Cuppen, C. Brinch, J. K. Jørgensen and M. R. HogerheijdeA&A, 516 (2010) A57DOI: https://doi.org/10.1051/0004-6361/201014182