UWM Physics Colloquium Hosts UBC Astrophysicist on Fast Radio Burst Detection

Astrophysicist Deborah Good presented the findings and research trajectories of eight recently discovered repeating fast radio bursts at a physics colloquium hosted by the UWM Physics Department and College of Letters and Science on Friday, Oct. 11. 

Good, a graduate student in physics and astronomy at the University of British Columbia, has been leading radio astronomy research with the CHIME telescope in Canada. The research is focused on the detection of repeating fast radio bursts, or FRB, which are mysterious flashes of intense energy from a radio source in space that last for only a few milliseconds.  

While scientists still aren’t certain where and why these bursts are happening, they predict the events to be coming from a compact extra-galactic source—outside of the Milky Way. Some of the suggested sources are black holes or rapidly rotating neutron stars, which are highly dense remnants of dead stars that can produce intense emissions of energy. Researchers are monitoring these events to scan for repeating sources that will help explain the properties of FRB. 

“What’s intriguing about fast radio bursts is that we get a chance to look at totally new sources and find out where they’re coming from and what they mean,” Good said. “We don’t get totally new sources of radio signals coming along all that often. Most of the things that we measure, we already know how and why it exists and where it’s coming from.” 

Researchers are investigating what the causes of the bursts are and where they are coming from. Scientists detected the first FRB in 2007 and have since published 100 more with another 100 observations that have not yet been published, according to Good. 

Good and her team at UBC have been monitoring FRB to look for repeating bursts. Earlier this year, the CHIME telescope detected eight repeaters and 13 one-off or single-burst sources, according to the online research publication server arXiv. Previously, only two repeating FRB had been detected. 

Currently, there are two teams of FRB theorists; those who believe all FRB repeat and that some repeating sources just haven’t occurred or been detected yet, and those who believe there are distinct sources that repeat and those that do not. 

Good, who got her undergraduate degree in engineering and physics at the Colorado School of Mines, is a doctoral student working as a part of CHIME’s FRB team. She also leads inquiry-based-learning labs and is involved in an outreach organization called Let’s Talk Science at UBC. 

“To me, this research is exciting because I get to answer questions that I don’t know the answers to, and I get to play with fun telescopes,” Good said. 

The colloquium was held in UWM’s Kenwood Interdisciplinary Research Complex Friday afternoon where Good presented the research efforts underway at CHIME. 

CHIME, or the Canadian Hydrogen Intensity Mapping Experiment, is a stationary radio telescope that maps the northern sky almost constantly searching for radio sources like FRB or pulsars, which are rotating neutron stars that emit powerful beams of electromagnetic energy. 

As a transient telescope, CHIME is stationary and instead scans the sky as the Earth moves. The array of half-pipe dishes has a mesh covering them so the Canadian Rocky “snow can fall through, but the light cannot,” according to Good. The dishes input radio frequencies from extragalactic sources—and terrestrial interference from cellphones and broadcast radio stations—and output data. 

The FRB team is using the detections at CHIME to harness a better understanding of the shape, structure and fate of the universe, according to Universe Today. 

“FRB research is fascinating,” said Robert Aloisi who often attends UWM’s physics colloquiums. “The number of them that they’re seeing right now and their ability to track some of them back down to the galaxy that they come from is really interesting research.” 

Detecting and predicting millisecond FRB sources has proven to be a challenging feat for scientists, according to Good. By monitoring the ten detected FRB repeaters and scanning for more sources, research is underway that aims to uncover the properties, location, causes and structures of the events. 

Good presented findings that showed the signal’s frequency would decrease slightly over the duration of the burst. She described this data structure as that of a “sad trombone” because it would sound like one if the data was transcribed into sound frequencies. Scientists are still unclear on if this is a unique property of repeating FRB. 

Some FRB repeaters have been detected up to 10 times, while other bursts have only been observed twice so far. Follow up work with FRB research has expanded to telescopes like the Arecibo Observatory in Puerto Rico, which has a larger dish that can increase exposure, detail and resolution.