Unveiling The Physics of Star Formation and Feedback in Galaxies

International audienceRecent studies show the importance of feedback in the evolution of the star formation rate in the Universe. However, the nature and physics of the feedback are still pressing questions. Radio continuum observations can provide unique dust-unbiased tracers of massive star formation and of the interstellar medium (ISM) and hence are ideal to address the regulation of star formation in galaxies. Our multi-frequency and multi-resolution radio surveys in nearby galaxies enable us to trace various phases of star formation and dissect the thermal and nonthermal ISM in galaxies. Mapping the cosmic ray electron energy index and magnetic field strength, we have found observational evidence that massive star formation significantly affects the energy balance in the ISM through the injection and acceleration of cosmic rays and the amplification of magnetic fields. How the next generation of stars could form in such a magnetized and turbulent ISM will be addressed in our 'EVLA cloud-scale survey of the local group galaxy M33' and in forthcoming surveys with the SKA