Intense Star Formation in the Early Universe

Apr 02, 2010
An optical image of Arp 220, a nearby example of a merged starburst galaxy. CfA astronomers have used the SMA to study what seems to be an analogous galaxy from a much earlier epoch, about ten billion years ago. They conclude that although the processes at work in the distant galaxy produce extreme luminosities, they closely resemble similar activity in local galaxies. Credit: NASA, ESA, the Hubble Heritage-ESA/Hubble Collaboration, and A. Evans (UVa/NRAO/Stony Brook)

(PhysOrg.com) -- Distant galaxies are not only far away in space. Because it takes time for their light to reach us, they are also very far away in time -- snapshots from the distant past.

The most distant known are seen as they were when the universe was less than a billion years old, and their light has been traveling towards us for over twelve billion years. Astronomers are able to study these remote, ancient galaxies because they are fantastically bright, some of them hundreds of times more luminous than our . Astronomers want to understand them because somehow these primeval galaxies develop into modern galaxies, like our own or others in our cosmic neighborhood. One outstanding question exists: what makes these galaxies so bright?

CfA astronomers Steve Longmore, Ray Blundell, Mark Gurwell, and Dave Wilner, together with eighteen of their colleagues, used the (SMA) and several other telescopes to study a luminous galaxy whose light has been traveling towards us for ten billion years. Unlike most other known, bright, but remote galaxies, this one is fortuitously situated directly behind (as seen from earth) a much closer cluster of galaxies whose gravity acts like a lens to re-image the light. That coincidence, combined with the SMA's unique ability to see very fine spatial details at submillimeter wavelengths, allowed the scientists to measure individual clouds of gas and dust in the far-away galaxy.

Writing in the latest issue of the journal Nature, the team reports that these clumps are similar to star-forming regions in the Milky Way, except larger and much more luminous. From these and other characteristics of the clumps, the scientists conclude that vigorous star-formation is underway in this galaxy with underlying physical processes that are similar to those in normal galaxies, just much more intense. The possible reasons for such extreme activity are less clear, but the authors suggest that a galaxy collision, such as is commonly seen in the local universe, can stimulate the production of these large clumps.

The new paper is significant both because it clearly determines the nature of the huge luminosities in this far-away galaxy, and because it implies that current recipes for modeling star formation can be applied to these extreme cases.

Explore further: Experts and audience contest Pluto's 'dwarf planet' status

Related Stories

Survey Reveals Building Block Process For Biggest Galaxies

Apr 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 ...

Antennae Galaxies

May 19, 2008

This image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies. During the course of the collision, billions of stars will be formed. The brightest and most compact of these star ...

Recommended for you

Finding hints of gravitational waves in the stars

5 hours ago

Scientists have shown how gravitational waves—invisible ripples in the fabric of space and time that propagate through the universe—might be "seen" by looking at the stars. The new model proposes that ...

How gamma ray telescopes work

6 hours ago

Yesterday I talked about the detection of gamma ray bursts, intense blasts of gamma rays that occasionally appear in distant galaxies. Gamma ray bursts were only detected when gamma ray satellites were put ...

The frequency of high-energy gamma ray bursts

8 hours ago

In the 1960s a series of satellites were built as part of Project Vela.  Project Vela was intended to detect violations of the 1963 ban on above ground testing of nuclear weapons.  The Vela satellites were ...

What causes the diffraction spikes in images of stars?

8 hours ago

When stars are portrayed in media, they are often shown with long spikes emanating from them. Perhaps the most common example is that of the "star of Bethlehem" which, according to the story, led the wise ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

vidyunmaya
1 / 5 (3) Apr 04, 2010
SUB: Onset of Luminous Phenomena in the Universe
ARP 220 :what makes these galaxies so bright?
Information:clearly determines the nature of the huge luminosities in this far-away galaxy, and because it implies that current recipes for modeling star formation can be applied to these extreme cases.
Comments: Cosmology Vedas Interlinks-Cosmic flow onset within the Universe
Vidyardhi Nanduri