CAREER: Focused Hard X-ray Study of Energy Releases on the Sun and Stellar Objects

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

This five-year CAREER project is intended to form an important link between the high-energy solar and astrophysics communities, and offers a rare opportunity to use the same high-energy telescope (NuSTAR) to study flares on the Sun and other stars. In tandem, undergraduate and graduate students will construct and run a set of citizen science projects aimed at the investigation of particle acceleration in solar flares using data from the past generation of (indirect) hard X-ray observations. The family of citizen science projects will serve the important purpose of education at the university level and will additionally serve as a solar physics outreach tool as we directly engage the public in high-energy research. Thus, education, outreach, and research are naturally integrated within the project. It is intended that these initial citizen science efforts will develop and blossom beyond the extent of this project, opening up citizen science as a platform to analyze the wealth of data provided by multi-wavelength observations of the Sun. In addition, this project will provide significant support for a relatively new solar physics research group at the University of Minnesota that includes several early-career women, directly affecting the future gender balance of the solar and stellar physics communities. The research and EPO agenda of this CAREER project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. The research program of this five-year CAREER project constitutes an integrated approach to studying particle acceleration and coronal heating associated with impulsive energy releases (flares) on the Sun and other stars. The main objective is to investigate how high-energy flare properties scale with total energy released by using newly available focused hard X-ray measurements. This objective will be achieved through three complementary efforts. Firstly, existing and anticipated data sets from the Nuclear Spectroscopic Telescope Array (NuSTAR) and the Focusing Optics X- ray Solar Imager (FOXSI) will be used to investigate the physics of small microflares on the Sun. Second, the first set of focused hard X-ray observations of young stellar objects (YSOs) will be analyzed to understand energy release in giant flares. Finally, a student-built family of citizen science projects will analyze solar flares observed over the last solar cycle by the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI) in order to unearth new insight into flare particle acceleration. The research agenda is expected to significantly advance flare knowledge by illuminating the physics of small-scale energy release in sub-A-class microflares -- a regime never before studied at high energies. Furthermore, the project will utilize never-before-available hard X-ray observations of YSO flares to investigate whether they are governed by the same processes of energy release, particle acceleration, and heating as in solar flares, and will ascertain the aspects of those flares that may have the ability to affect developing planetary systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.