Star-Forming Backbone of a Massive Structure in the Early Universe Photographed

May 20, 2009

( -- Using a special camera known as AzTEC developed by a research team led by Grant Wilson, astronomy professor at the University of Massachusetts Amherst, an international research group has imaged a set of ultra-massive galaxies that are thought to form the backbone of a super large structure, or collection of galaxies congregated together, in the very early universe.

The cluster of about 11.5 billion light years away is described in a recent issue of the journal, Nature, by lead investigator Yoichi Tamura of the University of Tokyo and Japan’s National Astronomy Observatory (NAOJ), with colleagues at UMass Amherst and other universities in Mexico and the United States. Their findings are very valuable for understanding how galaxies formed in the , when it was less than 2 billion years old, and at a time when clusters of galaxies were just beginning to be formed, the researchers say. The universe is estimated to be about 13.7 billion years old.

For this study, astronomer Min Yun at UMass Amherst, with Wilson and graduate students Jason Austermann, Kimberly Scott and others, pointed the telescope and the AzTEC camera toward the constellation Aquarius, an area known since the 1990s for hosting hundreds of small yet optically bright galaxies called Lyman alpha emitters in the remote Universe.

The new study provides the first direct observational evidence for coincident grouping of optically dim, ultra-massive, starbursting systems which may form the underlying backbone of the growing cluster very early in the universe’s life cycle, Wilson notes. “We call this star formation starbursting because it’s thought to be a rather violent and short-lived phase, about 50 million years, in the galaxy’s life,” he adds.

These ideas are consistent with those predicted by current thinking on the formation of cosmic structures in the Big Bang paradigm. And, the data are in general agreement with theories of how massive galaxies come to be preferentially found in galaxy clusters.

It’s exciting to find these ultra-massive galaxies coexisting beside the Lyman alpha emitters, which themselves have been caught in the act of forming a young cluster of galaxies, according to Wilson. “This is akin to finding a flock of owls congregating around a group of fireflies at night,” says Wilson. “We’ve known about the fireflies for several years because they glow and are relatively easy to see. But these recent measurements show there’s a lot more hidden in the darkness. Now the question is, are the fireflies there because of the owls, or are the owls there because of the fireflies?”

Further, as Wilson explains, the newly discovered galaxies are encased in a cocoon of dust created by their own prolific formation of new stars. Although they are some of the most massive galaxies formed and so the stars inside might be expected to be more visible, most of their optical light is unable to penetrate the dust, making the galaxies nearly invisible even to the most powerful optical instruments such as the Hubble Space Telescope. The AzTEC camera, destined to become part of UMass Amherst’s Large Millimeter Telescope, senses the thermal glow from this warm dust and allows astronomers to “see” the otherwise hidden galaxies.

AzTEC, the UMass Amherst instrument, was funded in part by the National Science Foundation. It will be installed at the Large Millimeter Telescope, a 50-meter millimeter-wavelength telescope nearing completion in Mexico. The 10-m submillimeter telescope, ASTE, is operated by NAOJ and the University of Tokyo in collaboration with the University of Chile, Nagoya University, Osaka Prefecture University, Ibaraki University, and Hokkaido University.

Provided by University of Massachusetts Amherst (news : web)

Explore further: Survey Reveals Building Block Process For Biggest Galaxies

Related Stories

Survey Reveals Building Block Process For Biggest Galaxies

April 12, 2006

A new study of the universe's most massive galaxy clusters shows how mergers play a critical role in their evolution. Astronomers used the twin Gemini Observatory instruments in Hawaii and Chile, and the Hubble Space Telescope ...

Massive galaxy cluster found 10 billion light years away

June 6, 2006

A University of Sussex astronomer is the lead researcher for a project that has led to the discovery of the most distant cluster of galaxies observed to date. The cluster, which is 10 billion light years from Earth, is also ...

Recommended for you

How to prepare for Mars? NASA consults Navy sub force

October 5, 2015

As NASA contemplates a manned voyage to Mars and the effects missions deeper into space could have on astronauts, it's tapping research from another outfit with experience sending people to the deep: the U.S. Navy submarine ...

Researchers find a new way to weigh a star

October 5, 2015

Researchers from the University of Southampton have developed a new method for measuring the mass of pulsars – highly magnetised rotating neutron stars formed from the remains of massive stars after they explode into supernovae.

NASA selects investigations for future key planetary mission

October 1, 2015

NASA has selected five science investigations for refinement during the next year as a first step in choosing one or two missions for flight opportunities as early as 2020. Three of those chosen have ties to NASA's Jet Propulsion ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet May 26, 2009
Fascinatng article, thanks!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.