Predicting star formation and metal enrichment in quasars for high-redshift ALMA observations

• Antragsteller: Professor Ralf Klessen, Ph.D.
• Fachliche Zuordnung: Astrophysik und Astronomie
• Förderung: Förderung von 2009 bis 2014
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 126893565

• Erstellungsjahr: 2011

Zusammenfassung der Projektergebnisse

The research project focused on the generation of magnetic fields in the early universe, in particular, during the gravitational collapse of the first minihalos. Recent advances in computer simulations of cosmological structure formation have suggested that the primordial gas in high redshift halos gas becomes highly turbulent during the formation of the first stars and the first galaxies. Using this information, we showed that in presence of turbulence, small-scale weak initial seed magnetic fields can be exponentially amplified by a process known as the small-scale dynamo to generate strong magnetic fields in the central collapsing core. The dynamo process provides additional amplification of the magnetic field strength over what could be achieved by pure gravitational compression of the field lines. Results obtained from our computer simulations show that gravitational collapse drives turbulence on scales of the order of the local Jeans length. This allows for the exponential amplification of magnetic fields on the smallest resolvable scales. We have further explored the influence of initial conditions on the magnetic field amplification during the collapse of a magnetized gas cloud. Our results not only hold true for the early universe but apply to all magnetized gravitating systems in general.

Projektbezogene Publikationen (Auswahl)

• 2010, Magnetic fields during primordial star formation, Proceedings of Science Cosmic Radiation Fields: Sources in the Early Universe, Hamburg
  Dominik R. G. Schleicher, Sharanya Sur, Robi Banerjee, Ralf S. Klessen, Christoph Federrath, T. G. Arshakian, Rainer Beck, Marco Spaans
  
• 2010, Probing high-redshift quasars with ALMA. I. Expected observables and potential number of sources, A &A, 513, A7
  Dominik R.G. Schleicher, Marco Spaans, Ralf S. Klessen
  
• 2010, Small-scale dynamo action during the formation of the first stars and galaxies. I. The ideal MHD limit, A&A., 522, A115
  Dominik R. G. Schleicher, Robi Banerjee, Sharanya Sur, T. G. Arshakian, Ralf S. Klessen, Rainer Beck & Marco Spaans
  
• 2010, The generation of strong magnetic fields during the formation of the first stars, ApJ, 721, L134
  Sharanya Sur, Dominik R. G. Schleicher, Robi Banerjee, Christoph Federrath, Ralf S. Klessen
  
• 2010, The generation of strong magnetic fields during the formation of the first stars, Proceedings of Science Cosmic Radiation Fields: Sources in the early Universe, Hamburg
  Sharanya Sur, Robi Banerjee, Ralf S. Klessen, Dominik R. G. Schleicher, Christoph Federrath
  
• 2011, A new Jeans resolution criterion for (M)HD simulations of self-gravitating gas: Application to magnetic field amplification by gravity-driven turbulence, ApJ, 731, 62
  Christoph Federrath, Sharanya Sur, Dominik R. G Schleicher, Robi Banerjee, Ralf S. Klessen