Descrizione del progetto
Scoprire il meccanismo dei campi magnetici ordinati nell’Universo
I campi magnetici permeano gran parte del cosmo. Un’osservazione eccezionale è che quasi tutti i corpi celesti con campi magnetici non mostrano una rete aggrovigliata, ma presentano invece una struttura magnetica ordinata. I campi magnetici ordinati sono così prevalenti nel nostro caotico universo che confondono gli astronomi che vogliono scoprire da dove provengono e come persistono in un tale caos. Le teorie all’avanguardia non sono in grado di spiegare a sufficienza come nasce questo ordine, specialmente in stelle simili al sole, proprio come il nostro Sole. Il progetto UniSDyn, finanziato dall’UE, intende sviluppare nuove simulazioni e strumenti di analisi dei dati per descrivere in modo più accurato i fenomeni dinamo in oggetti celesti, vale a dire i meccanismi che consentono loro di generare campi magnetici.
Obiettivo
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.
Campo scientifico
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-COG - Consolidator GrantIstituzione ospitante
02150 Espoo
Finlandia