The structures and star populations of massive galaxies appear to change as they age, but much about how these galaxies formed and evolved remains mysterious.
Many of the oldest and most massive galaxies reside in clusters, enormous structures where numerous galaxies are found concentrated together. Galaxy clusters in the early universe are thought to be key to understanding the lifecycles of old galaxies, but to date astronomers have located only a handful of these rare, distant structures.
New research from a team led by Carnegie's Andrew Newman has confirmed the presence of an unusually distant galaxy cluster, JKCS 041. It is published by the Astrophysical Journal.
"Our observations make this galaxy cluster one of the best-studied structures from the early universe," Newman said.
Although the team began studying JKCS 041 in 2006, it has taken years of observing with many of the world's most powerful telescopes to finally confirm its distance.
The team used the Hubble Space Telescope to capture sharp images of the distant cluster and split the starlight from the galaxies into its constituent colors, a technique known as spectroscopy. They found 19 galaxies at precisely the same great distance of 9.9 billion light years, the tell-tale sign of an early galaxy cluster.
A previous study using the Chandra X-ray Observatory discovered X-ray emissions in the location of JKCS 041.
"These X-rays likely originate from hot gas in JKCS 041, which has been heated to a temperature of about 80 million degrees by the gravity of the massive cluster," said team member Stefano Andreon of the Osservatorio Astronomico di Brera, who led a companion paper published by Astronomy & Astrophysics, which is available here.
Today the largest and oldest galaxies are found in clusters, but there is a mystery about when and why these giant galaxies stopped forming new stars and became dormant, or quiescent. Peering back to a time when the galaxies in JKCS 041 were only 1 billion years old---or 10 percent of their present age---the team found that most had already entered their quiescent phase.
"Because JKCS 041 is the most-distant known cluster of its size, it gives us a unique opportunity to study these old galaxies in detail and better understand their origins," Newman said.
Once massive galaxies enter their quiescent phase, they continue expanding in overall size. This is thought to occur as galaxies collide with one another and evolve into a new, larger galaxy. Early clusters are suspected to be prime locations for these collisions, but to the team's surprise they found that the galaxies in JKCS 041 were growing at nearly the same rate as non-cluster galaxies.
The international team included Newman, Andreon, Ginevra Trinchieri of the Osservatorio Astronomico di Brera, Richard Ellis of Caltech, Tommaso Treu of the University of California at Santa Barbara, and Anand Raichoor of the Observatorie di Paris.
This work was based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program number GO-12927, which was supported under NASA contract NAS 5-26555. The work was also supported by the agreement ASI-INAF I/009/10/0 and the Osservatorio Astronomico di Brera.
The Carnegie Institution for Science is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
Drew Newman | Eurek Alert!
Fast and Accurate 3-D Imaging Technique to Track Optically-Trapped Particles
24.04.2015 | Korea Advanced Institute of Science and Technology
Tau Ceti: The next Earth? Probably not
23.04.2015 | Arizona State University
KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.
Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...
A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...
Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.
Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...
Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.
In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...
23.04.2015 | Event News
23.04.2015 | Event News
13.04.2015 | Event News
24.04.2015 | Materials Sciences
24.04.2015 | Materials Sciences
24.04.2015 | Health and Medicine