WVU researcher,
Professor Duncan Lorimer, is part of an international team reporting activity
from a repeating source of fast radio bursts from a source in a galaxy around 3
billion light years away using the world’s largest telescope in China.
Image: A “river” of bursts from a galaxy as recorded by the FAST telescope. The
burst count and energies are shown in histograms, mimicking the painting “A Vast
Land” by WANG Ximeng of the Song Dynasty. (Image by NAOC)
Fast radio bursts, or FRBs, are transient radio pulses caused by astrophysical sources located well beyond our galaxy, the Milky Way. While the origins of these millisecond duration, bright, extragalactic flashes are still not fully understood, a community of a few hundred researchers worldwide are working to better understand their physical origins. While many FRBs are apparently one-off events, since 2012, astronomers have been frequently studying one particular source, FRB 121102, which was the first one conclusively shown to repeat. Among other characteristics, it has been determined that this particular FRB is associated with a persistent radio source, and scientists have identified its location in a dwarf galaxy some three billion light years from Earth. Further observations last year suggest that the activity of this burst is cyclical, with a period of 156 days.
WVU Physics and Astronomy Professor Duncan Lorimer, was on the international team whose results were published in Nature on Oct 14th, 2021. Currently serving as Associate Dean for Research in the Eberly College of Arts and Sciences at WVU, Lorimer is a member of the Center for Gravitational Waves and Cosmology for which FRBs is one of the major research areas. A familiar name in the world of FRBs, Lorimer pioneered the field while working with WVU undergraduate student, David Narkevic, which led to their discovery of the first fast radio burst in 2007.
Fast forward fourteen years, Lorimer was part of the team that caught an extreme
episode of bursts in 47 days. Using the
FAST (Five-hundred-meter Aperture Spherical radio telescope) in China, the
team detected 1,652 independent bursts over 47 days between August 29, 2019 and
October 29, 2019. Before this study, only 347 bursts had been identified from FRB
121102.
The large sample of bursts sheds new light on theoretical models of FRBs. For the
first time, the team is using this sample to better understand the characteristic
energy and energy distribution and aiming to further the understanding of the origins
of FRBs.
FAST catches a real pulse from FRB 121102 Credit: NAOC.
“The total energy of this burst set already adds up to only a few percent of what is available from a highly magnetized neutron star known as a magnetar. In addition, in spite of intensive searches, we found no evidence for any periodicity in the burst arrival times in the range 1 ms to 1000 s. Both of these exclude the possibility that FRB 121102 comes from an isolated compact object,” said Lorimer.