Project description
Uncovering the mechanism of ordered magnetic fields in the Universe
Magnetic fields permeate much of the cosmos. An outstanding observation is that almost all celestial bodies with magnetic fields do not show a tangled web, but instead present an ordered magnetic structure. Ordered magnetic fields are so prevalent in our chaotic universe that confuse astronomers who want to find out where they come from and how they persist in this chaos. State-of-the-art theories cannot sufficiently explain how this order arises, especially in solar-like stars just like our Sun. The EU-funded UniSDyn project plans to develop novel simulations and data analysis tools to more accurately describe the dynamo processes in celestial objects, namely the mechanisms that allow them to generate magnetic fields.
Objective
Magnetic fields are ubiquitous in the universe. The special property of cosmic magnetism is that, in the majority of objects hosting magnetic fields, those fields are organized, such that some meaningful averaging can reveal global structure and systematic behavior. In the Sun, averaging over longitude reveals the equatorward migration of the emergence region of the sunspots, forming the famous butterfly diagram. Further, vigorous turbulence is present in a wide variety of astrophysical systems, and yet they still exhibit organized magnetic fields. These observations prompt the search for a theory to explain how order can arise and sustain itself in such chaos. We claim that the available theories are incomplete, especially in the case of solar-like stars which becomes apparent if we view the Sun as one star among many. We propose a coherent plan of advancement in which each theory shall be tested by requiring it also to explain the cyclic dynamo action seen in more active rapid rotators.
UNISDYN project attacks these very problems with novel simulations and data analysis tools. Our path to resolve them is to enhance the state-of-the-art stellar dynamo models with the relevant descriptions of the turbulent processes. This goal is reached in three steps. (i) We will produce improved convection dynamo simulations to serve as laboratories from which (ii) the turbulent transport coefficients are directly measured with a novel test methods suite. (iii) Finally, global dynamo models incorporating the turbulent effects in full are constructed based on (i) and (ii) results. These results will allow us to unify stellar dynamo theory for solar-like inactive and rapidly rotating active stars. The developed toolbox has direct applications in other fields of astrophysics, such as accretion and galactic disk dynamos, and industry, such as combustion engines and fusion reactors.
Fields of science
Programme(s)
Funding Scheme
ERC-COG - Consolidator GrantHost institution
02150 Espoo
Finland