LOFAR observations of the solar corona during Parker Solar Probe perihelion passages

• Applicant: Dr. Christian Vocks
• Subject Area: Astrophysics and Astronomy
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 426501369

The LOw Frequency ARray (LOFAR) is a radio interferometer for the frequency range 10-240 MHz, that consists of a dense core and remote stations in the Netherlands, and international stations in various European countries. They form an interferometer with baselines up to 2000 km.NASA's Parker Solar Probe (PSP) spacecraft has approached the Sun up to 36 solar radii, or 0.166 AU, on its first perihelion passage on 5 November 2018. It is equipped with instruments to study the structure and dynamics of the solar wind plasma and magnetic field, the energy flow that heats the solar corona and drives the solar wind, and the mechanisms that accelerate energetic particles.LOFAR's capability of observing the solar corona and studying the heliosphere ideally complement PSP's in-situ and remote data. Simultaneous observations of the Sun and the inner heliosphere with LOFAR and PSP will enable studies of processes in the solar corona and near-Sun interplanetary space, monitoring both the formation of space-weather events and their subsequent propagation.The LOFAR Key Science Project (KSP) "Solar Physics and Space Weather with LOFAR", of which the applicants of this proposal are members, has been awarded a total of 1064 hours observing time during PSP perihelion passes over the next two years. These observations use LOFAR's simultaneously recorded interferometric data, dynamic radio spectra, interplanetary scintillation measurements, and pulsar observations for determining interplanetary magnetic fields.This proposal aims at evaluating these joint observations. The applicants' groups at UWM and AIP have long-standing experience in interferometric imaging of the solar corona and on the analysis of solar dynamic radio spectra, and focus on these parts of the LOFAR observations. The science cases include type II and III radio bursts, the quiet solar corona, and the plasma physics behind these observations. Combining such LOFAR observations with PSP data from near-Sun interplanetary space will provide information on, and constrain models of, solar wind and radio burst evolution from the corona into interplanetary space.This will result in a better understanding of the connection between the solarcorona and the heliosphere. This is a current science topic, and necessary for space weather studies, especially when it comes to predictions. The cooperation between the groups at UWM and AIP, funded through this proposal, would significantly support such scientific data analysis of the joint LOFAR – PSP observations. Both groups have experience in solar imaging and radio burst studies, and a closer collaboration between them will enable a better use of synergies between them. The implementation of the grant will support the creation of research groups at both institutions, dealing with the conduct and use of observations from LOFAR. Thanks to this, it will be possible to fully use the possibilities of this instrument and making it a unique research tool.

• DFG Programme: Research Grants
• International Connection: Poland
• Partner Organisation: Narodowe Centrum Nauki (NCN)
• Co-Investigator: Professor Dr. Gottfried Mann
• Cooperation Partners: Dr. Bartosz Dabrowski; Professor Dr. Andrzej Krankowski