Astronomers have found several candidates for large galaxies in the early Universe, including one with a possible stellar mass equivalent to 1 billion times that of the Sun. They appeared to the team as glowing red “pins” in a patch of sky the size of a marker dot drawn on a thumb held out at arm’s length.
The team behind the new discovery were shocked and thrilled. The features of these ancient spots, whose light traveled through space for most of the Universe’s history, had never been seen this way before. They suggest some interesting possibilities. Even just 500 to 800 million years after the Big Bang, these galaxies appear together. The assembly of galaxies and stars may have started earlier than previously thought. The team may also be looking at a long-ago supermassive black hole.
The work, described in an article published Wednesday in Nature, is the latest science to emerge about the deep Universe with the James Webb Space Telescope (JWST). Equipped with four instruments sensitive to cold temperatures about a million miles from Earth, the JWST is capable of resolving objects that are faint in the eyes of predecessors like the Hubble Space Telescope.
‘Fun and intense’
Ivo Labbé, lead author of the paper and an associate professor of astronomy at Swinburne University of Technology in Australia, begins the story of the new research on July 11, 2022, the momentous Monday on which President Biden announced the debut image of the telescope. Less than 24 hours later, NASA, the European Space Agency and the Canadian Space Agency released four more exciting observations.
Astronomers were “dizzy”, says Labbé reverse. And the days that followed were “fun and intense,” says Rachel Bezanson, associate professor of astronomy at the University of Pittsburgh and co-author of the paper. reverse. Some astronomers were in a race to be the first to publish about the ancient galaxies hidden in the now public observations. Others were happy to play with the data on their new science toy.
Labbé and Bezanson decided to look for something new. They saw an opportunity with the bullet-sized patch of sky. It’s the region that JWST observed during CEERS, or the Cosmic Evolution Early Release Science Survey. CEERS took place a month before the first images from the space telescope were aired to validate JWST’s ability to search galaxies. This was a demo, says Labbé, but it was always designed for everyone to use when the data became public. Labbé, Bezanson and the team decided to look for bright red dots in the survey.
UFOs: Ultra-Red Flat Objects
Labbé says they were jokingly looking for UFOs: ultra-red flat objects. Team member Erica Nelson found several red disks, says Labbé. “And then she showed one of them, which looked like a little pin prick. Like a red dot. And when I looked in more detail, I almost spit out the coffee,” says Labbé.
“I’ve been looking at these types of data for a while now. And I immediately knew what I was looking at. I was looking at what looked like a very massive galaxy… and I thought, well, if there’s one, there must be more,” says Labbé. “And so I designed a survey that was specifically targeting these things and what they look like. And then I found a bunch of them.
The emission lines from these objects suggest a “surprisingly high” number of stars in them, says Labbé. “It was 10 or 100 times larger than you would expect based on what Hubble had seen.”
Bezanson says these galaxy candidates appear to be older and more evolved than anticipated, perhaps already out of the turbulent youthful chapter in their development. “We think they went through a more significant fraction of their lives than we would have expected, than we would have been so bold as to suggest we would have seen,” says Bezanson.
What is the next
There are still questions. The mass inside these galaxies could be stars. But part of what they see could be heated gas, glowing as it churns around the outer edge of a supermassive black hole. These types of glowing gravitational wells are called quasars. And if spectroscopy (a technique that analyzes the composition of light) reveals what part of the mass belongs to a quasar, it could open doors to understanding how gigantic black holes at the centers of galaxies contributed to their development over the ages.
Labbé and Bezanson will continue to look for older galaxies. Bezanson said he will use the natural magnification of a galaxy cluster that bends light, for example, to see deeper into space.
For now, these ancient galaxy candidates remain an exciting prospect. They have the potential to rewrite the early stages of the formation of the largest galaxies in the Universe.