Màster Oficial d'Astrofísica, Física de Partícules i Cosmologia, Facultat de Física, Universitat de Barcelona, Curs: 2016-2017, Tutors: Gemma Busquet, Robert EstalellaA distinguished kind of molecular clouds, the infrared dark clouds (hereafter IRDCs), are
believed to be relevant for describing the initial conditions for high-mass star formation. They are characterized by their lack of detectable emission in the mid-infrared: they appear as a dark silhouette against the corresponding mid-infrared background. IRDCs were first recognized in images from the Infrared Space Observatory (ISO, Egan et al. 1998) and the Midcourse Space Experiment (MSX, Perault et al. 1996
