The unique work of CHIME, a set of radio telescopes that looks at a slice of the north-south sky from horizon-to-horizon near Penticton, British Columbia, garnered the interprovincial team the Brockhouse Canada Prize — one of the top science honours granted by the federal government.
CHIME, which stands for Canadian Hydrogen Intensity Mapping Experiment, surveys a large swath of sky to provide valuable context for celestial events, while also looking at numerous things happening at the same time. It is different from a telescope, such as the Hubble Space Telescope, which zooms into one small area to map it in high definition.
“We’re proud that Canada chose to do a thing that was risky — scientifically risky — and funded it and got it to work,” said Mark Halpern, principal investigator of CHIME at the University of British Columbia.
CHIME saw its first light in September 2017, and has already generated dozens of scientific papers in the five years since. It caught fast radio bursts, which are “snicks of light” that flash as quickly as an eye blink, according to Halpern.
CHIME caught about 3,000 of these unique (yet still poorly understood) phases that may come from stars or other energetic sources — as opposed to around two dozen seen before the telescope was built. It also monitored thousands of rapidly spinning, dense stars known as pulsars. And because of the wide field of view, it can constantly revisit the same stars again and again.
“We’ve learned two things from that: one is you learn what the pulsars are up to, or how does the pulse change over time? But in my own personal view, the more exciting thing is they’re travelling through space,” said Halpern.
The team has seen gravity waves from big celestial events (such as black holes merging) change the timing of pulsars as well. “We’ve built a gravity wave detector for gravity waves, which have a period of a month [to capture] very long, low frequency waves like you would get from huge events.”
The benefits do not just accrue to scientific knowledge, as CHIME is a young observatory and still growing; the team is working on getting more “outrigger” telescopes built into the system to increase its sensitivity and range. Instrument builders and astronomers, including students, have a unique opportunity to work on a telescope still under construction.
“Students working on it now, getting their degrees, helped physically build it,” said Halpern. “They’re out there, stringing cables and so forth. But more importantly, they are making design decisions about how the amplifiers work, or what noise source we use to adjust the timing of the system, or how the digital system works.”
Halpern said the opportunity to receive this type of training allows students to see the full “design and use lifecycle” across five to seven years of telescope components, and to learn when to use commercial components to increase reliability and cut down cost.
According to Halpern, it is also a different experience than using Hubble which, while groundbreaking in its own right, has not seen any upgrades since astronauts last visited it in 2009. Hubble also was designed in the 1980s — a generation before today’s undergraduates were even born.
Looking ahead, Halpern said getting more outriggers installed with CHIME is “super important”; one is ready and more will be put in next year. The increased telescope sensitivity will allow CHIME to detect more fast radio bursts and pulsars than before, and refine their data so it is more precise.
“There’ll be as much exciting news in the next couple of years as there’s been in the last,” said Halpern of CHIME.
This biweekly column by Canadian science and space journalist Elizabeth Howell focuses on a trending news topic in Canadian astronomy and space.