Energetic Ions and Electrons in Solar Jets

• Applicant: Professor Dr. Bernd Heber, since 10/2019
• Subject Area: Astrophysics and Astronomy
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 411010162

Acceleration of ions and electrons in stellar flares is ubiquitous in the universe, however, our Sun is the only astrophysical object where energetic particles and their source flares can be jointly observed. The acceleration mechanism in solar flares, tremendously enhancing (up to factors of ten thousand) rare elements like 3He and ultra-heavy nuclei (like 197Au and 207Pb), has been puzzling for almost 50 years and presents one of the most extreme fractionation examples in astrophysics. The measured heavy-ion enhancement, increasing with ion mass, conflicts with the strongest enhancement which occurs for low-mass 3He element indicating that more than one mechanism is involved in the ion acceleration. Flares associated with escaping energetic particles have been commonly observed in jet-like forms, implying magnetic reconnection comprising field lines open to interplanetary space. This project aims to advance our understanding of the ion enhancement mechanisms operating in solar flares addressing for the first time the association between the energetic ions and electrons and their solar sources. Specifically, the project resolves 1) how different are solar sources in events with a common ion and electron detection compared to sources where only one particle component is dominant, and 2) to what extent is the injection/transport to/in interplanetary space responsible for lack of ion or electron detection. The objective 1) will be addressed by relating unprecedented high-resolution imaging observations of the jet structure and underlying magnetic fields with the in-situ observed properties of energetic ions and electrons. The objective 2) will be addressed by relating injection delays (between the low and high energy electrons and between electrons and ions) with solar source characteristics.

• DFG Programme: Research Grants
• International Connection: China
• Partner Organisation: National Natural Science Foundation of China
• Cooperation Partner: Professorin Linghua Wang, Ph.D.
• Ehemaliger Antragsteller: Radoslav Bucik, Ph.D., until 10/2019