JWST Observes Early Galaxies Around Red Quasar
The James Webb Space Telescope (JWST) launched in October 2021 and is already bouncing between sharper images of the cosmos and super cool scientific discoveries. Now it found some massive galaxies that formed 11.5 billion years ago in a cluster with a red quasar in the center.
The quasar in question is a type of active galactic nucleus (AGN), a region in the center of galaxies with a supermassive black hole at the center and an accretion disk that can be brighter than all the galaxy’s stars. The bright glow comes from matter from the accretion disc falling into the black hole that gives off one last burst of radiation before falling through the event horizon and disappearing from the universe altogether.
PBS Explains Quasars in This Video
The ancient quasar that JWST found was already red but such significant redshift due to its distance from Earth that it took the JWST’s sensitive infrared sensors to pick it up.
NASA described the quasar as one of the most powerful galactic nuclei that it can detect at such a vast distance. Its emissions can cause a galactic wind that could have pushed free gas out of the galaxy and impacted stellar formation. Researchers are using JWST’s Near Infrared Spectrograph (NIRSpec) instrument to study the movement of dust, gas and stellar material around the quasar. NIRSpec can simultaneously collect data on the quasar, its galaxy, and the surrounding space.
Researchers previously observed the quasar using the Hubble Space Telescope. However, Hubble’s instruments were not sensitive enough to pick up the surrounding cluster of galaxies.
JWST’s more sensitive instruments found three more galaxies rapidly orbiting the quasar. They are surprisingly close together, indicating that this cluster could have been one of the most densely packed clusters in the early universe.
“There are few galaxy protoclusters known at this early time. It’s hard to find them, and very few have had time to form since the big bang,” said Dominika Wylezalek, an astronomer at the Heidelberg University in Germany who led the study that found the three newly discovered galaxies.
Wylezalek believes dark matter could be a factor in the formation of these closely orbiting galaxies, but “even a dense knot of dark matter isn’t sufficient to explain it. … We think we could be seeing a region where two massive halos of dark matter are merging together.”
Scientists are working on new techniques to find evidence of dark matter’s influence of the universe but can’t observe it directly – hence the name. It could form a halo that extends beyond stars.
Wylezalek’s research team is planning further observations of the region around this red quasar. Comparing data from JWST to archival data from Hubble might lead to more of these elusive early galaxies. Hubble’s Wide Field Camera 3 returned images hinting at extended material surrounding the quasar’s home galaxy, potentially giving Wylezalek’s team or other researchers some clues that can help them refine future observations of the region. Wylezalek said they could be looking at the core of a whole cluster of galaxies.
A paper on this newly discovered cluster of galaxies will be published in The Astrophysical Journal Letters. The research is based on 28 hours of allocated observation time with the JWST.
