The Great Laboratory M51: Probing the Physics of Star Formation and Radio Emission on the 100pc-Scale

• Applicant: Dr. Eva Schinnerer
• Subject Area: Astrophysics and Astronomy
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 41960361

The empirical radio-IR relation is widely used out to high-z to estimate star formation rates (SFRs), despite the fact that its origin is poorly understood. Processes within giant molecular clouds where stars form (at the 100 pc scale) must control it. The grand-design spiral M51 is ideal for a detailed study of the underlying physics of the radio-SFR relation, due to the range of physical conditions in the spiral disk, and the large body of high-resolution (1-2") data available from the X-ray to the radio. Our imaging radio data from the VLA and Effelsberg observatories at 20cm, 6cm and 4cm are ideally suited to study the nature of the radio emission (thermal/nonthermal decomposition, turn-over frequency) and to test whether the radio emission is indeed an unbiased tracer of star formation, over a wide range of physical environments. In addition, we have high resolution mid-IR imaging spectroscopic data from the Spitzer telescope which will be used for an in-depth study of a density wave in a spiral region. Both datasets combined will provide new and critical insight into the star formation process in the disks of galaxies. In short, continued funding for the post-doc G. Dumas is requested to (a) to study the radio-IR relation on GMC scale, (b) to compare the applicability of star formation tracer from the UV to the radio, and (c) to gain a physical picture of a spiral density wave.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1177: Witnesses of Cosmic History: Formation and Evolution of Black Holes, Galaxies and Their Environments
• Participating Person: Dr. Rainer Beck