A protocluster of seven galaxies has been confirmed a distance of redshift 7.9 for the first time.
According to the European Space Agency – an international partner on the James Webb Space Telescope with NASA and the Canadian Space Agency – the term “redshift” refers to how the wavelength of light is stretched and seen as “shifted” toward the red part of the electromagnetic spectrum.
The higher the redshift, the farther away – and back in time – the source.
In this case, the protocluster of galaxies were a mere 650 million years after the big bang, according to data collected using the telescope. Using this data, astronomers calculated the cluster’s future development, finding that it will likely grow in size and mass to resemble the Coma Cluster.
The Coma Cluster contains thousands of galaxies and is more than 20 million light-years in diameter.
The measurements captured by the telescope’s Near-Infrared Spectograph, one of Webb’s instruments, were key to confirming the galaxies’ distance and the high velocities are moving with a halo of dark matter, at more than two million miles per hour.
“This is a very special, unique site of accelerated galaxy evolution, and Webb gave us the unprecedented ability to measure the velocities of these seven galaxies and confidently confirm that they are bound together in a protocluster,” IPAC-California Institute of Technology’s Takahiro Morishita, the lead author of the study published in the Astrophysical Journal Letters, said in a statement.
Galaxy clusters are the greatest concentrations of mass in the known universe, and they can dramatically warp the fabric of spacetime in a process called “gravitational lensing.”
The researchers were able to look through Pandora’s Cluster to view the protocluster, thanks to this magnifying effect.
The seven galaxies confirmed by Webb were first established as candidates for observation using the Hubble Space Telescope’s Frontier Fields program, which dedicated Hubble time toward observations using gravitational lensing. However, while Hubble cannot detect light beyond near-infrared, Webb was designed to observe infrared wavelengths.
The observatory detailed spectroscopic data in addition to imagery.
NASA’s Nancy Grace Roman Space Telescope will have 200 times Hubble’s infrared field of view in a single shot and will be able to identify more protocluster galaxy candidates. That mission is targeted for launch by May 2027.