Heliophysics Science: High-Energy Aspects of Solar Flares

Organization National Aeronautics and Space Administration (NASA) Reference Code 0032-NPP-NOV26-GSFC-HelioSci Description The NASA Postdoctoral Program (NPP) offers unique research opportunities to highly‑talented scientists to engage in ongoing NASA research projects at a NASA Center, NASA Headquarters, or at a NASA‑affiliated research institute. These one‑ to three‑year fellowships are competitive and are designed to advance NASA’s missions in space science, Earth science, aeronautics, space operations, exploration systems, and astrobiology. The acceleration of charged particles to high energies and their confinement, transport, and subsequent energy losses are among the fundamental processes of solar flares. We investigate these processes through observations of X‑rays and gamma rays and through theoretical modeling. Our most recent observational effort was the Reuven Ramaty High‑Energy Solar Spectroscopic Imager (RHESSI), a Small Explorer mission operational from February 2002 through April 2018. It conducted the first high‑resolution X‑ray and gamma‑ray imaging spectroscopy of solar flares using cooled germanium detectors and Fourier‑transform imaging in the energy range from 3 keV to 20 MeV. RHESSI provided high‑resolution observations that are reshaping our understanding of particle acceleration in flares. We also continue to analyze data sets from the Solar Maximum Mission, the Compton Gamma Ray Observatory, the Japanese Yohkoh spacecraft, and the Fermi astrophysics mission. Data are available for tens of thousands of flares and are complemented by ground‑based radio and optical observations. This comprehensive array of observational data is available online at the Solar Data Analysis Center in Goddard’s Solar Physics Branch and provides critical tests of theoretical models. We are developing an integrated package of modular numeric codes and models for the analysis and interpretation of these data. The package focuses on energetic electrons produced during the impulsive phase of flares and computes both bremsstrahlung X‑ray/gamma‑ray emission and gyrosynchrotron radio emission from model configurations and initial electron distributions. Steady‑state and time‑dependent Fokker‑Planck codes compute the transport of suprathermal electrons, and a hydrodynamic code will compute the response of the flare plasma in the model configurations. The predicted emissions can be compared directly with X‑ray/gamma‑ray and radio images and spectra, providing a framework for comparing electron acceleration models with flare data. In addition, we conduct research programs to develop solid‑state detectors with high spectral resolution that operate at or near room temperature, high‑spatial‑resolution scintillation detectors for use as image‑plane detectors for hard X‑ray and gamma‑ray observations, and a new telescope concept utilizing two high‑Z Fresnel zone plates to image at hard X‑ray energies. The combination of instrument development, data analysis, and theoretical modeling makes this opportunity suitable for a wide range of talents. A solar‑physics background is advantageous but not required. Location Goddard Space Flight Center Greenbelt, Maryland Field of Science Heliophysics Science Advisors Steven Christe View email address on click.appcast.io View phone number on click.appcast.io Albert Y. Shih View email address on click.appcast.io View phone number on click.appcast.io Eligibility Requirements Doctoral Degree U.S. Citizens U.S. Lawful Permanent Residents (LPR) Foreign Nationals eligible for an Exchange Visitor J‑1 visa status Applicants for LPR, asylees, or refugees in the U.S. at the time of application with a valid EAD card and I‑485 or I‑589 forms pending Applications from citizens of designated countries are not accepted unless they are Legal Permanent Residents of the United States. A complete list of Designated Countries can be found at: Contact Questions about this opportunity? Please email View email address on click.appcast.io Point of Contact Mikeala #J-18808-Ljbffr ORAU