The University of Alabama in Huntsville hopes to investigate the energy jets that stream off stars when they die or merge.
Teaming up with Marshall Space Flight Center, the Center for Space Plasma and Aeronomic Researcher (CSPAR) at UAH has a significant role in LEAP — LargE Area burst Polarimeter — one of four proposals being reviewed by NASA to be the next astrophysics missions under the Explorers Program. NASA will select two of the proposals in 2021, with a projected target launch date of 2025.
LEAP will use a Compton telescope mounted on the International Space Station to study the energetic jets launched during an explosive death of a massive star or the merger of compact objects, such as neutron stars. LEAP would be able to determine the angle of polarization and the energy of each gamma-ray created, answering some fundamental questions. LEAP would complement NASA’s Imaging X-ray Polarimetry Explorer (IXPE), scheduled to launch in 2021.
LEAP’s principal investigator is Mark McConnell, at the University of New Hampshire in Durham.
At UAH, CSPAR Assistant Director and Associate Chair of the Department of Space Science Robert Preece would be the university’s principal investigator and the science data manager for the LEAP collaboration, responsible for the timely delivery of science-ready data to the NASA public archive. In addition, CSPAR Assistant Director and Research Scientist Michael Briggs would provide expertise in flight software design and algorithms.
Marshall Space Flight Center is providing the project manager, Karen Gelmis, its deputy principal investigator, Jessica Gaskin, and its project scientist, Colleen Wilson-Hodge.
“Once a day on the average, somewhere in the universe, from a random spot in the sky, the level of gamma-ray radiation dramatically increases for a few seconds to a few hours,” said Preece. “Many important details about bursts are completely unknown, although we have some good guesses.”
Researchers are interested in gamma-ray polarization because it can provide more information and potentially answer some of the unknowns.
“Specifically, when there’s significant polarization found, there are likely to be magnetic fields around, and magnetic fields are the most efficient way to produce the gamma-rays that we see. Until now, we haven’t got the proof that magnetic fields are involved, nor do we know to what level their contribution is,” Preece said.
Solar flares also can exhibit polarization, and, if selected, the mission would launch in a period of increasing solar activity.
“It is also possible to monitor gamma-ray emitting pulsars for possible polarization,” Preece said. “We will also be searching for another neutron star merger, similar to the one Fermi GBM saw on August 17, 2017, with the gravitational wave observatories.”
Being aboard the ISS will provide the mission with connectivity to the ground, allowing for prompt communication to other observatories of interesting events.