James Webb telescope captures ancient galaxy deemed too big for its age
Scientists have used the James Webb Space Telescope to study an 11.5 billion-year-old galaxy significantly larger than the Milky Way.
The study, published in the Nature science journal on February 15, has tested scientists’ understanding of how galaxies form and the nature of dark matter.
Dark matter – comprising invisible particles that do not emit, absorb or reflect light – makes up most of the universe and provides the necessary gravitational pull to attract and hold gas and dust together. This is the process that led to the formation of stars and galaxies in the early universe.
But the latest research has shown that the galaxy, called ZF-UDS-7329, appears to be too large to account for the amount of dark matter that was present at the time it was formed.
Claudia Lagos of the International Centre for Radio Astronomy Research played a crucial role in creating the theoretical models for the study, explaining how dark matter concentrations have changed over time. “Galaxy formation is in large part dictated by how dark matter concentrates,” she said.
“Having these extremely massive galaxies so early in the universe is posing significant challenges to our standard model of cosmology.
“This is because we don’t think such massive dark matter structures as to host these massive galaxies have had time yet to form,” Ms Lagos said, adding that further investigation is required to understand how common these galaxies may be and how truly massive they are.
Scientists had worked for seven years to capture data on this galaxy and used two large ground-based telescopes to determine its age.
However, the galaxy was too red and faint to be measured properly, so experts had to use the James Webb Space Telescope to confirm its nature.
The telescope, which cost $10 billion, is the most advanced space observatory ever built and uses a 6.5-metre mirror to collect light from faint, distant objects.
It captures them in the infrared spectrum, a type of light that is invisible to the human eye but can be identified as heat by scientific instruments to observe distant and cold objects in deep space.
Prof Karl Glazebrook, who led the study, voiced hope that the findings could represent a breakthrough in scientists’ understanding of the physics of dark matter.
“The James Webb Space Telescope has been finding increasing evidence for massive galaxies forming early in time,” he said.
“This result sets a new record for this phenomenon. Although it is very striking, it is only one object.
“But we hope to find more, and if we do, this will really upset our ideas of galaxy formation.”