May 2, 2024

Mysteriously High Fraction of Dead Galaxies Found in Ancient Galactic City – Unlike All Other Known Protoclusters

This artists impression illustrates the development of a galaxy cluster in the early Universe. The galaxies are strongly forming new stars and communicating with each other. Such a scene closely resembles the Spiderweb Galaxy (formally referred to as MRC 1138-262) and its surroundings, which is one of the best-studied protoclusters. Credit: ESO/M. Kornmesser
Why clusters galaxies are unlike those in all the other known protoclusters is a secret, says UC Riverside-led team.
An international team of astronomers led by researchers at the University of California, Riverside, has actually discovered an uncommon enormous cluster of young galaxies forming in the early universe. The recently found growing stellar metropolitan area, named MAGAZ3NE J095924 +022537, is a newborn galaxy cluster, or protocluster, consisting of at least 38 member galaxies, and has to do with 11.8 billion light-years away from Earth.
Galaxy clusters grow gradually under gravity and, in the contemporary universe, can consist of hundreds and even countless galaxies, in addition to hot gas and dark matter. As time goes by, their galaxies burn through the fuel available and develop from vigorously star-forming galaxies into dead and red galaxies.

” In the early universe, all protoclusters found previously have plenty of strongly star-forming galaxies,” said Ian McConachie, a graduate trainee in the UC Riverside Department of Physics and Astronomy and the lead author of the term paper released in The Astrophysical Journal. “But exceptionally, unlike all of the other protoclusters that have been found at this date, many galaxies in MAGAZ3NE J0959 appear to have currently stopped forming stars.”
Coauthor Gillian Wilson, a teacher of physics and astronomy at UCR in whose laboratory McConachie works, said J0959 was found from the “Massive Ancient Galaxies At Z > > 3 NEar-infrared,” or MAGAZ3NE, survey, created to find and study ultramassive galaxies and their neighbors.
In the early universe, all formerly found distant protoclusters like, for example, “The Spiderweb” (left: artists impression) are full of intensely star-forming galaxies. In contrast, the newly-discovered protocluster “MAGAZ3NE J095924 +022537” consists of a high fraction of red and dead galaxies like the close-by “Coma” cluster (right).
” We are seeing this protocluster as it appeared when the universe was less than 2 billion years of ages,” she stated. “It is as if you took a cluster like Coma, the closest abundant cluster of galaxies to Earth, and plopped it into the early universe.”
Coauthor Benjamin Forrest, a previous postdoctoral researcher in Wilsons lab who is now based at UC Davis, described that at the heart of MAGAZ3NE J0959 is an ultramassive galaxy that has actually already formed a mass of more than 200 billion suns.
” Why this ultramassive galaxy and so a number of its next-door neighbors formed most of their stars and after that ended up being inactive when the universe was still so young, in contrast to other known protoclusters from the very same time, is a big mystery,” he said. “Why its galaxies are so unlike those in all the other recognized protoclusters, and so similar to those in Coma, is a complete secret.”
Forrest included that MAGAZ3NE J0959 was discovered from the ground, however the advent of effective brand-new abilities, like the recently-launched James Webb Space Telescope, need to soon expose whether there are other protoclusters like MAGAZ3NE J0959 packed with dead galaxies waiting to be discovered in the early universe.
” Should such protoclusters be discovered in great deals, it would indicate that the existing paradigm of protocluster formation would need a significant revision,” Forrest said. “A new circumstance of protoclusters existing in a diversity of states in the early universe would have to be embraced. With numerous member galaxies quenching in the first 2 billion years, this would probably posture considerable obstacles for present designs of galaxy simulation.”
The team used spectroscopic observations from the W. M. Keck Observatorys Multi-Object Spectrograph for Infrared Exploration, or MOSFIRE, to make in-depth measurements of MAGAZ3NE J0959 and precisely quantify its distances.
Closely associated to the concern of how ultramassive galaxies form is the question of the environment in which they form, for instance, are they constantly discovered in overdense environments like protoclusters, or can they likewise form in isolation? Next, the group plans to study the neighborhood of all other ultramassive galaxies in the MAGAZ3NE survey to answer this question.
Recommendation: “Spectroscopic Confirmation of a Protocluster at z = 3.37 with a High Fraction of Quiescent Galaxies” by Ian McConachie, Gillian Wilson, Ben Forrest, Z. Cemile Marsan, Adam Muzzin, M. C. Cooper, Marianna Annunziatella, Danilo Marchesini, Jeffrey C. C. Chan, Percy Gomez, Mohamed H. Abdullah, Paolo Saracco and Julie Nantais, 9 February 2022, The Astrophysical Journal.DOI: 10.3847/ 1538-4357/ ac2b9f.
Other scientists involved in the research study are Cemile Marsan and Adam Muzzin of York University, Canada; Michael Cooper of UC Irvine; Marianna Annunziatella and Danilo Marchesini of Tufts University; Jeffrey Chan and Mohamed Abdullah of UCR; Percy Gomez of Keck Observatory; Paolo Saracco of Astronomical Observatory of Brera, Italy; Julie Nantais of Andrés Bello National University, Santiago, Chile.
The research study was supported by grants from the National Science Foundation and NASA.

Such a scene closely resembles the Spiderweb Galaxy (officially known as MRC 1138-262) and its environments, which is one of the best-studied protoclusters. In the early universe, all formerly discovered remote protoclusters like, for example, “The Spiderweb” (left: artists impression) are complete of strongly star-forming galaxies. In contrast, the newly-discovered protocluster “MAGAZ3NE J095924 +022537” consists of a high fraction of red and dead galaxies like the nearby “Coma” cluster (right). The discovery of an ancient cluster including galaxies which resemble those discovered in contemporary clusters was a big surprise. With lots of member galaxies satiating in the first two billion years, this would nearly definitely posture substantial obstacles for current designs of galaxy simulation.”