Quiet-Sun Magnetic Fields and Newly Emerging Flux - Dynamics, Energetics, and Upper Atmospheric Response

• Applicant: Professor Dr. Carsten Denker
• Subject Area: Astrophysics and Astronomy
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 391070020

Exploring the complex tension and intricate relationship between the ubiquitous quiet-Sun magnetic fields and newly emerging flux motivates this German-Czech research cooperation. The Leibniz Institute for Astrophysics Potsdam (AIP) and the Astronomical Institute - Academy of Sciences of the Czech Republic (ASU) propose to jointly investigate small-scale photospheric and chromospheric magnetic fields. Newly emerging flux regions (EFRs) exhibit photospheric signatures affecting the regular granulation pattern, creating micro-pores and pores, and eventually leading to larger, more complex structures like active regions including groups of pores and sunspots. The chromospheric response to emerging flux are field-aligned dark structures containing cool plasma. These arch filament systems (AFSs) are seen prominently in the strong chromospheric absorption line H-alpha and in the near-infrared (NIR) He I triplet at 1083.0 nm. A rising system of Omega-loops best describes the observed properties of EFRs and AFSs but only provides an illustration of the flux emergence process rather than a full description of the underlying physics. Therefore, we will trace newly emerging flux from the photosphere, over chromosphere and transition region, to the corona, derive its three-dimensional magnetic field topology, evaluate the stability of the magnetic field configuration, and examine energy input and balance in various atmospheric layers. We will investigate how (magneto)acoustic chromospheric waves and small-scale magnetic reconnection contribute to the energy input of the corona. The general theme of the proposed project is the fundamental solar process of the interaction between plasma motions and magnetic fields. Our investigation is founded in imaging and NIR spectropolarimetry with the GREGOR solar telescope, combining high-resolution ground-based observations with magnetic field and extreme ultraviolet data from space missions. The 1.5-meter GREGOR telescope is Europe's largest solar telescope and a premier facility for high-resolution solar physics. The proposed research project will significantly contribute to definition of science cases, design of observing campaign, evaluation of data reduction and analysis methods, and preparation of researchers for the next generation of large-aperture solar telescopes like the U.S. American Daniel K. Inouye Solar Telescope (DKIST) and the European Solar Telescope (EST).

• DFG Programme: Research Grants
• International Connection: Czech Republic
• Partner Organisation: Czech Science Foundation
• Co-Investigators: Dr. Horst Balthasar; Dr. Christoph Kuckein; Dr. Meetu Verma
• Cooperation Partners: Professor Dr. Petr Heinzel; Jan Jurcak, Ph.D.; Professor Dr. Michal Sobotka; Michal Svanda, Ph.D.