Ten Canadians have been selected to lead teams that will use the James Webb Space Telescope for scientific observations, with another 72 serving as co-investigators.
Webb is the next generation of space observatory, orbiting in a stable location between the Earth and the Sun — a Lagrange point — to peer far into the Universe. Its work will be vast, encompassing areas like studying exoplanet atmospheres, refining the cosmos’ expansion rate, and learning about how early galaxies were formed.
The telescope is expected to launch this fall, if final preparations go to plan, and after a commissioning period it will lean hard into scientific work around 2022.
Given Webb’s huge span of capability and the long wait time to get it in space — it was supposed to launch in 2007, but faced a few technical, logistical and budgetary problems along the way — the telescope has a huge backlog of interest from scientists, eager to stretch their research with the new capabilities.
“Anyone in the world could put in a proposal,” said Sarah Gallagher, an astronomy professor at Western University who also serves as the Canadian Space Agency’s science advisor to the president, in an interview.
Canada, however, is allocated a certain amount of minimum telescope time because of its hardware contributions to the telescope: a guidance sensor (to keep it pointed in the right direction) and an instrument known as the Near-Infrared Imager and Slitless Spectrograph. The instrument can, among other applications, look at exoplanet atmospheres or more easily separate the view of objects that are close together in Webb’s view of the sky.
Figuring out which applications would be selected, however, was still a difficult process, Gallgher said. The reviewers followed a “double-blind” procedure, requiring them to review proposals with the scientists’ names stripped out and also requiring different committee members not to disclose any names they may know to the other reviewers. This process is an evolution from Hubble Space Telescope observation selections, refined since the telescope first accepted proposals in the early 1990s, Gallagher added.
The selected topics from Canada cover a wide range of investigations showing our country’s strength in numerous astronomical topics, she said. The accepted Canadian proposals include study of objects like black holes, galaxies and extrasolar solar systems as well as the fundamentals of star physics, endeavouring to follow up on previous observations done by Canadian teams.
One example is a proposal to extend previous work at the Virgo Cluster, a group of galaxies roughly 55 million light-years away from Earth in the constellation Virgo. The Canada France-Hawaii Telescope (CFHT) collected six years of data with a “Next Generation Virgo Cluster Survey”, using a 340-megapixel camera mounted on the telescope that could observe up to four full Moons’ worth of space at a time. Using these observations and advanced data analysis, Canada’s National Research Council-led team found many more galaxies within the cluster than were known before.
“This huge dataset is incredibly rich, and it creates questions,” Gallagher said, adding that one question was whether there may be black holes within the centres of these newly found galaxies. The resolution of the CFHT is too low, and also does not provide information about how the velocities of stars, which would hint at any gravitational disturbances of nearby black holes. Webb’s high-definition observations of Virgo, she said, could zoom in on certain galaxies and measure the needed stellar velocities. This study will also tell astronomers more about how galaxies and black holes were formed more generally.
Gallagher said Webb is just one example showing how partnerships with Canadian astronomers and international astronomers allow the community to build an “ecosystem,” giving Canadians access to international missions through supplying a bit of hardware and expertise. (The same thing happens with Canadian astronauts and International Space Station scientists, for example, who get access to the orbiting facility thanks to Canada’s longstanding robotic contributions, such as Canadarm2 and Dextre.)
“It’s not like somebody handing out cookies,” Gallagher joked about the access Canada and other countries received for Webb, as the 286 selected investigations so far are based on scientific merit and contribution. More rounds of selection will come in future years, as Webb completes the first scientific round of investigations and time opens up for more work.
Gallagher said that when Webb launches, it will bring back memories of when she was a graduate student in 1999, watching the Chandra X-Ray Observatory launching to space inside the payload bay of the space shuttle Columbia. Gallagher was on the Chandra team and said that from that experience, “everyone’s hearts will be in their hands for the [Webb] launch.”
“It’s exhilarating and so stressful,” she continued. “Space can be risky and scary, but they [Webb engineers] have done everything to test and retest all of the different subsystems to have the highest chance of everything going well.”
This biweekly column by Canadian science and space journalist Elizabeth Howell focuses on a trending news topic in Canadian astronomy and space.