Deciphering the interstellar medium around the Scorpius-Centarus OB association

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We propose to study the complex structure and evolution of the interstellar medium (ISM) in the vicinity of the Scorpius-Centaurus OB association. As this is the nearest region of recent massive star formation, multi-wavelength observations can provide a unique opportunity to investigate in detail how the well known population of massive stars in Sco-Cen feeds the ISM with kinetic energy, ionizing radiation, and nucleosynthesis ejecta, and how this feedback created the observed systems of superbubbles surrounding the association and destroyed the parental molecular cloud. We will also test the scenario that this stellar feedback swept up new dense molecular clouds and triggered the formation of new generations of stars in these clouds. We will couple the MPE population synthesis code with hydrodynamical simulations in order to follow radioactive tracers, ejected from the massive stars as an independent signature of the evolution of the interstellar environment and the mixing of different gas phases. The theoretical predictions from the numerical simulations will be compared with the observational data to test the models.In the two years since the start of this project, we have collected numerous observations of the ScoCen complex across a wide range of wavelengths, from the radio to the gamma-ray regime, that we can now use to characterize the ISM in and around ScoCen.We use data from Planck, Herschel, and our new observations with the APEX sub-mm telescope to study the structure and the physical parameters of the cold dense clouds, in particular the Lupus I molecular cloud, that was probably created by the interaction of two colliding bubbles. We have been recently granted further time at the APEX telescope to observe the CO line emission in selected parts of the Lupus clouds; this will reveal the kinematics of the molecular gas in unprecedented resolution. In order to trace the warmer and more diffuse gas, we analyze new 21 cm HI radio data from the Parkes Galactic All Sky Survey, which provide very detailed information about the structure and kinematics of the expanding bubbles. Our analysis of the radioactivity gamma-rays as measured with INTEGRAL and the diffuse X-ray emission will trace the supernova- and wind-outputs of the massive stars. In the second funding period, we will combine all these data sets to obtain a comprehensive picture of the structure and dynamics of the ISM in Sco-Cen. Confronting the numerical simulations to these data should finally lead to a self-consistent model of the origin, evolution, and fate of the Sco-Cen complex.