Dense Cosmic Knot Found by Webb Telescope in the Early Universe

A visible and near-infrared Hubble Space Telescope image highlights the quasar SDSS J165202.64+172852.3 on the left. On the right, observations from the James Webb Space Telescope in multiple wavelengths demonstrating the distribution and motions of gas within a newly observed galaxy cluster around the central quasar. Credits: NASA, ESA, CSA, STScI, D. Wylezalek (Heidelberg Univ.), A. Vayner and N. Zakamska (Johns Hopkins Univ.) and the Q-3D Team

October 20, 2022

One of the most potent galactic nuclei ever observed at such a great distance is this quasar. Scientists had hypothesized that the quasar's intense emission might produce a "galactic wind," which would force free gas out of its host galaxy and perhaps have a significant impact on future star formation there.

The researchers used the telescope's Near Infrared Spectrograph to look into the motion of the gas, dust, and star material in the galaxy (NIRSpec). This sophisticated device examines the motion of numerous outflows and winds surrounding the quasar using a method known as spectroscopy. Instead of only collecting data from one spot at a time, NIRSpec can simultaneously collect spectra from the whole field of view of the telescope, allowing Webb to simultaneously study the quasar, its galaxy, and the larger universe.

The quasar's strong outflows were previously noted by NASA's Hubble Space Telescope and other observatories, and astronomers conjectured that its host galaxy might be merging with an unidentified companion. However, the researchers did not anticipate that Webb's NIRSpec data would show that there were at least three other galaxies spinning around it, not just one. The motions of all this surrounding material could be tracked thanks to spectra covering a wide area, which led to the discovery that the red quasar was in fact a component of a dense knot of galaxy formation.

The team was able to confirm three galactic companions to this quasar and demonstrate how they are connected using the images from NIRSpec. Hubble archived data suggest that there might be much more. The quasar was chosen for this investigation of its outflow and the repercussions on its host galaxy because images from Hubble's Wide Field Camera 3 had indicated extended material surrounding the quasar and its galaxy. The team now believes they may have been viewing the center of an entire cluster of galaxies, which has only recently been made visible by Webb's precise photography.

The fact that the three verified galaxies are orbiting one another at such high speeds suggests that a significant amount of matter is there. The team thinks this is one of the densest known regions of galaxy formation in the early cosmos because of how densely they are clustered in the area surrounding this quasar. Wylezalek claims that even a tight knot of dark matter is insufficient to account for it. "We believe we may be observing an area where two enormous dark matter halos are fusing together." It is believed that dark matter, an unobservable element of the cosmos, forms a "halo" around these stars, holding galaxies and galaxy clusters together.

The research by Wylezalek's team is a component of Webb's early universe studies. The telescope is already being used to study how the first galaxies began and evolved, as well as how black holes emerged and affected the structure of the universe, thanks to its unmatched ability to see back in time. Follow-up observations into this surprising galaxy proto-cluster are being planned by the researchers in an effort to learn more about how dense, chaotic galaxy clusters like this one emerge and how the active, supermassive black hole at its center affects them.

Source - NASA