YCAA Seminar: “Gravity or turbulence? Virial state and scaling relations of molecular clouds” Javier Ballesteros-Paredes, Instituto de Radioastronomia y Astrofísica, UNAM

Traditionally it has been thought that turbulence plays a key role in the formation of the structure and support of molecular clouds (MCs). But if instead non-thermal motions are in the result of hierarchical and chaotic collapse, as models of cloud formation and evolution suggest, many of the properties of the turbulence model need to be reviewed. In this talk I will present the observational signatures for the model of global collapse. To mention some: the supersonic linewidths on global scales and subsonic at core level, the virial appearance of MCs, the nature of the scaling relations, the shape of the stellar ages histogram, the column density probability distribution function, the fragmentation level of cores in MCs, and the filamentary structure of MCs. I will also discuss at which level internal turbulence can really provide support and provide structure to molecular clouds.