Reviewing Molecular Clouds

MANUEL FERNANDEZ LOPEZ

Conferencia; Star Formation from Cores to Clusters; 2017

The star formation process involves a wide range of spatial scales,densities and temperatures. Herschel observations of the cold and lowdensity molecular gas extending tens of parsecs, that constitutes thebulk of the molecular clouds of the Milky Way, have shown a network ofdense structures in the shape of filaments. These filaments supposedlycondense into higher density clumps to form individual stars or stellarclusters. The study of the kinematics of the filaments throughsingle-dish observations suggests the presence of gas flows along thefilaments, oscillatory motions due to gravity infall, and the existenceof substructure inside filaments that may be threaded by twisted fibers.A few molecular clouds have been mapped with interferometric resolutionsbringing more insight into the filament structure.Compression due to large-scale supersonic flows is the preferred mechanism to explain filament formation although the exact nature of the filaments, their origin and evolution are still not well understood. Determining theturbulence drivers behind the origin of the filaments, the relativeimportance of turbulence, gravity and magnetic fields on regulating thefilament structure and evolution, and providing detailed insight on thesubstructure inside the filaments are among the current open questionsin this research area.