Halifax researcher to study 'baby galaxies' using new space telescope

A space telescope launching next week will carry with it the hopes and dreams of a Halifax researcher Marcin Sawicki, who helped develop an instrument on board.

The telescope will be able to take pictures of the first stars that appeared in the universe after the Big Bang.

The James Webb Space Telescope is scheduled to launch on Dec. 24 at the earliest from the spaceport in French Guiana in South America.

The telescope, the size of a school bus while it's nestled in the nose of the rocket, will unfurl to the size of a tennis court once it reaches its final destination about 1.5 million kilometres from Earth — five or six times the distance to the moon.

The telescope is so sensitive it will be able to capture images of what the first stars in the universe looked like about 13.5 billion years ago. That's how long it has taken for the light to reach us.

"When the universe came out of the Big Bang, there were no stars, no galaxies, no light," said Sawicki, a professor in the department of astronomy and physics at Saint Mary's University and the director of the Institute for Computational Astrophysics. "It was a very, very, very dark place.

"We expect that the first stars started turning on in the very first galaxies. And so Webb is built to find, to detect these very, very first sources of light — cosmic dawn, as we like to say."

For the past 20 years, Sawicki has been involved in the development of an instrument called NIRISS — Near Infrared Imager and Slitless Spectrograph — that will be on board the telescope.

The device will make it possible to detect very distant galaxies and exoplanets, or planets that orbit around stars outside our solar system.

NIRISS splits the light from everything in its field of view into a spectrum, like a rainbow, Sawicki said. By looking at the intensity of the different colours, the scientists will be able to tell how far away an object is.

The spectrograph is one of two Canadian-built instruments on board the telescope, along with a fine guidance sensor, which will allow the telescope to remain locked on a specific target.

Because of Sawicki's involvement, he and his team will have exclusive access to some of the telescope's data for one year.

100 times stronger than Hubble

The Webb telescope is about 100 times more powerful than its predecessor, the Hubble, which can capture light from about 12 billion years ago. The difference between what those early galaxies — what Sawicki calls "baby galaxies" — look like from Hubble and what they'll look like from Webb is immense, he said.

"It's sort of the difference between seeing newborn babies and seeing toddlers, you know, kids in kindergarten. That's a huge difference."

Sawicki said he thinks it's important to learn more about the early galaxies because they contain the history of Earth and every human being on it.

"Those stars, like our sun, contain a lot of chemical elements that were made in earlier generations of stars. And so every chemical element in your body, except for hydrogen has been made in a star," he said.

"It's our history, it's our past, it's our origins. That's the exciting thing about it, looking back into the past to see where we come from."

In addition to showing what the early galaxies looked like, the telescope will help scientists understand how galaxies grow over time, Sawicki said.

"What kind of physical changes happen in them? How quickly do they build up their bodies, their mass, assemble new stars, produce these chemical elements?"

Once the Webb telescope arrives at its destination, it will go through a series of tests before starting to send data in about six months.