How teenage galaxies feed themselves

   Mar 15, 7:05 pm

Washington, Mar 15 (ANI): Astronomers have known for quite some time that the earliest galaxies were considerably smaller than the impressive spiral and elliptical galaxies that now fill the Universe.

Over the lifetime of the cosmos galaxies have put on a great deal of weight but their food, and eating habits , are still mysterious.

A new survey of carefully selected galaxies has focussed on their teenage years - roughly the period from about 3 to 5 billion years after the Big Bang.

By employing the state-of-the-art instruments on ESO's Very Large Telescope an international team is unravelling what really happened.

In more than one hundred hours of observations the team has collected the biggest ever set of detailed observations of gas-rich galaxies at this early stage of their development.

"Two different ways of growing galaxies are competing: violent merging events when larger galaxies eat smaller ones, or a smoother and continuous flow of gas onto galaxies. Both can lead to lots of new stars being created," explained Thierry Contini (IRAP, Toulouse, France), who leads the work.

The new results point toward a big change in the cosmic evolution of galaxies, when the Universe was between 3 and 5 billion years old.

Smooth gas flow (eso1040) seems to have been a big factor in the building of galaxies in the very young Universe, whereas mergers became more important later.

"To understand how galaxies grew and evolved we need to look at them in the greatest possible detail. The SINFONI instrument on ESO's VLT is one of the most powerful tools in the world to dissect young and distant galaxies. It plays the same role that a microscope does for a biologist," said Thierry Contini.

Distant galaxies like the ones in the survey are just tiny faint blobs in the sky, but the high image quality from the VLT used with the SINFONI instrument means that the astronomers can make maps of how different parts of the galaxies are moving and what they are made of.

There were some surprises.

"For me, the biggest surprise was the discovery of many galaxies with no rotation of their gas. Such galaxies are not observed in the nearby Universe. None of the current theories predict these objects," said Benoit Epinat, another member of the team.

"We also didn't expect that so many of the young galaxies in the survey would have heavier elements concentrated in their outer parts - this is the exact opposite of what we see in galaxies today," added Contini. (ANI)

Did ET actually trespass Earth's atmosphere? Oct 2, 12:51 pm
Melbourne, Oct 2 (ANI): Space experts were left astonished when they saw a video of Unidentified Flying Object (UFO) in the northern suburbs of Oregon and appeared to show a bright object drifting through the sunset.
Full Story
NASA finds signs of water on Mars Sep 29, 8:06 am
Johannesburg, Sept 29 (ANI): Water, water everywhere! After multiple experiments and tests NASA has announced that liquid water has been found on Mars that may harbor hopes of some life forms on the planet.
Full Story
Aliens, water, life? NASA to reveal `major finding` related to Mars Sep 27, 1:08 pm
London, Sept. 27 (ANI): NASA is all set to reveal about a major finding that could be related to life on Mars.
Full Story
'Cosmic fossils' shed light on galactic evolution Sep 26, 7:22 am
Washington D.C, Sept 26 (ANI): Fossils of galaxies have revealed the formation and evolution of massive galaxies.
Full Story