Resumen
Present day star formation (SF) takes place in giant molecular clouds (GMCs). These contain a wealth of structures on all length-scales with highly supersonic motions and it is believed that these supersonic motions induce the observed density inhomogeneities in the gas that drive star formation. Candidates for driving supersonic motions and SF include supernova shocks. Considering the physical conditions that are relevant for triggering star formation in interactions of SN shocks with neutral clouds, we have built diagrams of the SNR radius versus the cloud density in which the conditions above constrain a zone where star formation induced by SN shock front-cloud interactions is allowed. The diagrams are also tested with fully 3D-MHD radiative cooling simulations of a SNR with a self-gravitating cloud. We find that the numerical analysis is consistent with the predictions by the diagrams. The inclusion of a homogeneous magnetic field approximately perpendicular to the impact velocity of the SNR with an intensity ∼ 1 μG within the cloud results in only a small reduction of the star formation zone in the diagrams, a larger magnetic field (∼ 10 μG) causes a significant reduction. Application of our results to real star formation regions in our own galaxy have revealed that their formation could be consistent with this mechanism. Finally, we have evaluated the effective global star formation efficiency of this type of interactions and found that it is smaller than the observed values in our own Galaxy (SFE ∼ 0.01 - 0.3). This is consistent with previous work and also suggests that the currently investigated mechanism, although very powerful for driving structure formation, supersonic turbulence, and eventually, local star formation, does not seem to be sufficient to drive global star formation in normal star forming galaxies, not even when the magnetic field in the neutral clouds is neglected.
