Using NASA’s James Webb Space Telescope, astronomers studying the early universe have made an astonishing discovery: a cluster of massive galaxies evolving around an incredibly red quasar.
At left, the quasar SDSS J165202.64+172852.3 is highlighted in a Hubble Space Telescope image taken in visible and near-infrared light. The right and bottom images present new observations from the James Webb Space Telescope at different wavelengths. They demonstrate the distribution and motion of gas within a newly observed galaxy cluster around the central quasar. Image credit: NASA, ESA, CSA, STScI, D. Wylezalek (Heidelberg Univ.), A. Vayner and N. Zakamska (Johns Hopkins Univ.) and the Q-3D team
The discovery will lead to a better understanding of how galaxy clusters in the early universe combined to build the cosmic web that exists today.
A narrow region of supermassive black hole at the center of a galaxy is known as a quasar, a specific type of active galactic nucleus (AGN). The quasar is so bright that it outshine every star in the galaxy as a result of gas falling into a supermassive black hole.
It took Webb 11.5 billion years to discover the quasar, designated SDSS J165202.64+172852.3. In addition to its natural red color, the galaxy’s extreme distance has also red-shifted its light, giving it an extremely red color.
Webb was therefore well equipped to study the galaxy in detail thanks to his unparalleled sensitivity to infrared wavelengths.
One of the most powerful galactic nuclei ever observed at such a significant distance is this quasar. Scientists have hypothesized that the quasar’s intense radiation could produce a “galactic wind” that would push free gas away from the host galaxy and perhaps have a significant impact on future star formation there.
The researchers used the telescope’s Near Infrared Spectrograph (NIRSpec) to look at the movement of gas, dust and stellar material in the galaxy. This advanced instrument studies the movement of numerous streams and winds around the quasar using a method known as spectroscopy.
Webb can simultaneously study the quasar, its galaxy, and larger surroundings because of NIRSpec’s ability to simultaneously acquire spectra across the telescope’s field of view, rather than just from one location at a time.
The quasar’s intense outflows had previously been noted by NASA’s Hubble Space Telescope and other observatories, and astronomers suggested that its host galaxy may be merging with an unidentified companion.
What the researchers didn’t expect, however, was that Webb’s NIRSpec data would show that there are at least three other galaxies orbiting it, not just one. The motions of all this surrounding material can be traced with the spectra covering a wide area, leading to the discovery that the red quasar is actually part of a dense cluster of galaxy formation.
Few galactic protoclusters are known at this early time. They are hard to find and very few had time to form after the big bang. This could ultimately help us understand how galaxies evolve in a dense medium. This is an exciting result.
Dominika Villezalek, study leader and astronomer, Heidelberg University
The team was able to confirm and demonstrate the connections between three galactic companions of this quasar using the NIRSpec images. There may be even more, according to archived Hubble data.
The quasar and its galaxy were chosen for this study of its outflow and impact on its host galaxy because Hubble’s Wide Field Camera 3 images revealed extended material surrounding it. As a result of Webb’s precise image, the team now believes they may have seen the center of an entire cluster of galaxies.
Our first look at the data quickly revealed clear signs of large-scale interactions between neighboring galaxies. The sensitivity of the NIRSpec instrument was immediately apparent and it was clear to me that we were in a new era of infrared spectroscopy.
Andrei Weiner, Postdoctoral Fellow, Physics and Astronomy, Johns Hopkins University
The fact that the three galaxies examined are rotating around each other at such high speeds suggests that a significant amount of mass is present. The team believes this is one of the densest known regions of galaxy formation in the early universe because of how densely they are clustered in the region around this quasar.
Wylezalek added: “Even a dense knot of dark matter is not enough to explain it. We think we can see a region where two massive dark matter haloes are merging together.
Dark matter, an unobservable element of the cosmos, is thought to form a “halo” around these stars, holding galaxies and galaxy clusters together.
The Wylezalek team’s research was part of Webb’s early studies of the universe. The telescope is already being used to study how the first galaxies formed and evolved, as well as how black holes formed and affected the structure of the universe, thanks to its unparalleled ability to see back in time.
The researchers plan follow-up studies of this surprising galactic proto-cluster in an attempt to learn more about how dense, chaotic galactic clusters like this one form and how the active, supermassive black hole at its center affects them.
These findings will be published in The Astrophysical Journal Letters. The study was completed as part of Webb’s Early Release Science Program #1335.
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