The Principal Investigator (PI) will study thermal and nonthermal radio emission from solar flares through a combination of high resolution radio observations and sophisticated theoretical modeling. The PI's project team intends to develop new analytical methods and software tools for processing imaging radio spectroscopy data, in order to enhance the scientific output of existing radio observatory instruments (which are currently being actively upgraded), as well as the output of future instruments. The PI plans to develop a number of new models to exploit the latest observations and theories, and to create new methods for forward-fitting of radio spectroscopic imaging data and for measuring the diagnostics of high-energy electrons and plasma parameters in solar flaring regions.
The PI's forward-fitting inversion methods, when combined with high-resolution imaging spectroscopy data, will enable the solar community to derive the key physical parameters of flares on dynamic time scales with unprecedented spatial resolution. Such investigations will directly address the fundamental questions of magnetic reconnection and particle acceleration processes in solar physics.
This activity will include enhance scientific understanding throughout the discipline of astrophysics, since the processes of energy release and charged particle acceleration are common to most astrophysical systems. An increased understanding of the physics of energy release, transformation, and transfer in the solar atmosphere is directly applicable to space weather forecasting. The user-friendly software developed by the project team will be made widely available to the solar and space weather communities through the internet-based "SolarSoft" repository. The team will be actively involved in teaching, training, and learning through the Center for Solar-Terrestrial Research (CSTR) at the New Jersey Institute of Technology. The software tools created in this project will be widely used in graduate courses taught at CSTR in solar physics, radio astronomy, and plasma physics.
The project outcome includes new knowledge on the fundamental science problem of how the solar flare work as well as computer codes, simulation tools, theory of particle acceleration and radiation from solar flares needed to model, analyze, and deeply understand modern observational data on the solar flares and wisely plan further observations. The project outcome is documented in more than 20 publications including 11 journal articles in scientific journals, 3 one-time publications (including one textbook), and more than 10 conference contributions, which have garnered more than 50 citations. Intellectual merit. We developed a new modeling tool, the GX simulator, which is capable to quickly compute a potential or linear force-free magnetic datacube from extrapolation from a (photospheric) base map of the line-of-sight magnetic measurements and, so, form a framework for realistic 3D modeling of active regions and flaring loops (see attached images). Further, this tool is capable of quickly computing X-ray emission and microwave emission based on a new fast codes developed under the project support. Also, the tool supports easy multi-wavelength and model-to-data map comparison. Using this tool for in-depth data analysis we obtained new knowledge on the particle heating, acceleration, and transport in solar flares including the very early flare phase. We discovered a new class of solar flares – cold, tenuous flares dominated in the radio domain, but very weak in soft X-ray domain. We also upgraded our Spike Explorer tool to accommodate non-Gaussian statistical noise distributions, which is needed for the analyzing spectral data from Fourier instruments, i. e., from most of the modern radio spectrometers including FST, Phoenix, and Calisto. New forward fitting algorithm deriving the parameter maps (for the coronal magnetic field, fast electron density and spectral index) from the microwave imaging spectropolarimetry data has been developed and successfully tested on model EOVSA data. Models of radio emission from flares, developed within the project, directly impacted the design of a significant extension of the existing imaging radio instrument, Owens Valley Solar Array, progressing now toward completion in late 2013. Broader impacts. The most powerful and flexible of the tools developed, GX Simulator, has been included into the Solar SoftWare (SSW) distribution, see www.lmsal.com/solarsoft/ssw_packages_info.html and so is now freely available for every SSW user. The modeling tools has been disseminated between many research groups and is actively used by our colleagues indicative for the project team to become broadly internationally recognized in this area. The PI on the grant, in collaboration with Professor Toptygin, has completed a new textbook published by Springer, 'Cosmic lectrodynamics' (ISBN:978-1-4614-5781-7), some Chapters and Sections of which are directly relevant to the Grant topics. This textbook is supposed to serve as a core source for undergrad and grad courses. GS simulation tool is used in teaching graduate courses (most recently – 'Radio Astronomy' during Spring semester, 2012) to develop student understanding and assign written report projects.
