Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ancient Galaxy Cluster Still Producing Stars

19.08.2010
Much like quiet, middle-aged baby boomers peacefully residing in some of the world’s largest cities, families of some galaxies also have a hidden wild youth that they only now are revealing for the first time, according to research by astronomers at Texas A&M University.

In ongoing observations of one of the universe’s earliest, most distant cluster of galaxies using NASA’s Spitzer Space Telescope, an international team of researchers led by Texas A&M’s Dr. Kim-Vy Tran has discovered that a significant fraction of those ancient galaxies are still actively forming stars.

Tran, an assistant professor in the Texas A&M Department of Physics and Astronomy and member of the George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and her team have spent the past four months analyzing images taken from the Multiband Imaging Photometer for Spitzer (MIPS), essentially looking back in time nearly 10 billion years at a high red-shift cluster known as CLG J02182-05102. Mere months after first discovering the cluster and the fact that it is shockingly “modern” in its appearance and size despite being observed just 4 billion years after the Big Bang, the Texas A&M-led team was able to determine that the galaxy cluster produces hundreds to thousands of new stars every year — a far higher birthrate than what is present in nearby galaxies.

What is particularly striking, according to Tran, is the fact that the stellar birthrate is higher in the cluster’s center than at the cluster’s edges — the exact opposite of what happens in our local portion of the universe, where the cores of galaxy clusters are known to be galactic graveyards full of massive elliptical galaxies composed of old stars.

“A well-established hallmark of galaxy evolution in action is how the fraction of star-forming galaxies decreases with increasing galaxy density,” explains Tran, lead author of the team’s study which appears in The Astrophysical Journal Letters. “In other words, there are more star-forming galaxies in the field than in the crowded cores of galaxy clusters. However, in our cluster, we find many galaxies with star-formation rates comparable to their cousins in the lower-density field environment.”

Exactly why this star power increases as galaxies become more crowded remains a mystery. Tran thinks the densely-populated surroundings could lead to galaxies triggering activity in one another, or that all galaxies were extremely active when the universe was young.

The group’s discovery holds potentially compelling implications that could ultimately reveal more about how such massive galaxies form. Observations of nearby galaxy clusters confirm that they are made of stars that are at least 8 to 10 billion years old, which means that CLG J02182-05102 is nearing the end of its hyperactive star-building period.

Now that they have pinpointed the epoch when galaxy clusters are making the last of their stars, astronomers can focus on understanding why massive assemblies of galaxies transition from very active to passive. Identifying how long it takes for galaxies in clusters to build up their stellar mass as well as the time at which they stop provides strong constraints for how these massive galaxies form.

“Our study shows that by looking farther into the distant universe, we have revealed the missing link between the active galaxies and the quiescent behemoths that live in the local universe,” Tran adds. “Our discovery indicates that future studies of galaxy clusters in this red-shift range should be particularly fruitful for understanding how these massive galaxies form as a function of their environment.”

Tran’s team includes fellow Texas A&M astronomer Dr. Casey Papovich, who first identified the galaxy cluster CLG J02182-05102 in May. The collection of roughly 60 galaxies is observed just 4 billion years after the Big Bang, making it the earliest cluster of galaxies ever detected. However, the team was struck not by its age, but by its astoundingly modern appearance — a huge, red collection of galaxies typical in only local clusters.

The fact that Tran’s team was able to see these active galaxies so far back in time (Tran likens their find to discovering that her mild-mannered grandparent had lived a fast and furious youth) is only the preface to what they expect eventually to learn about these clusters. Tran will continue to lead an international collaboration with Papovich and their postdoctoral researchers to examine these clusters more thoroughly and hopefully to understand why they are still so energetic.

“We will analyze new observations scheduled to be taken with the Hubble Space Telescope and Herschel Space Telescope to study these galaxies more carefully to understand why they are so active,” Tran adds. “We will also start looking at several more distant galaxy clusters to see if we find similar behavior.”

The team’s findings are detailed in their paper, “Reversal of Fortune: Confirmation of an Increasing Star Formation-Density Relation in a Cluster at z=1.62,” available online at http://iopscience.iop.org/2041-8205/719/2/L126/.

For or additional information on Texas A&M Astronomy, visit http://astronomy.tamu.edu.

NASA/JPL-Caltech Feature: http://www.spitzer.caltech.edu/news/1172-feature10-14

Contact: Chris Jarvis, (979) 845-7246 or Dr. Kim-Vy Tran, (979) 862-2747

Dr. Kim-Vy Tran | EurekAlert!
Further information:
http://www.tamu.edu

More articles from Physics and Astronomy:

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

nachricht New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>