Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




STELLAR CHEMISTRY
Star factory in the early Universe challenges galaxy evolution theory
by Staff Writers
London UK (SPX) Apr 22, 2013


Artist's impression of starburst galaxy HFLS3. The galaxy appears as little more than a faint, red smudge in images from ESA's Herschel space observatory, but appearances can be deceiving for it is making stars more than 2000 times faster than our own Milky Way, one of the highest star formation rates ever seen in any galaxy. Amazingly, it is seen at a time when the Universe was less than a billion years old, challenging galaxy evolution theories. Credit: ESA-C. Carreau. For a larger version of this image please go here.

A team including Mat Page (UCL Space and Climate Physics) has discovered an extremely distant galaxy making stars more than 2000 times faster than our own Milky Way. Seen at a time when the Universe was less than a billion years old, its mere existence challenges our theories of galaxy evolution. The observations were carried out using the European Space Agency's Herschel Space Observatory.

The galaxy, known as HFLS3, appears as little more than a faint, red smudge in images from the Herschel Multi-tiered Extragalactic Survey (HerMES). Yet appearances can be deceiving: this small smudge is actually a star-building factory, furiously transforming gas and dust into new stars.

Our own Milky Way makes stars at a rate equivalent to one solar mass per year, but HFLS3 is seen to be churning out new stars at more than two thousand times more rapidly. This is one of the highest star formation rates ever seen in any galaxy.

The extreme distance to HFLS3 means that its light has travelled for almost 13 billion years across space before reaching us. We therefore see it as it existed in the infant Universe, just 880 million years after the Big Bang or at 6.5% of the Universe's current age.

Even at that young age, HFLS3 was already close to the mass of the Milky Way, with roughly 140 billion times the mass of the Sun in the form of stars and star-forming material. After another 13 billion years, it should have grown to be as big as the most massive galaxies known in the local Universe.

This makes the object an enigma. According to current theories of galaxy evolution, galaxies as massive as HFLS3 should not be present so soon after the Big Bang.

The first galaxies to form are expected to be relatively small and lightweight, containing only a few billion times the mass of our Sun. They form their first stars at rates of a few times that experienced by the Milky Way today.

The small galaxies then grow by feeding off cold gas from intergalactic space and by merging with other small galaxies. So, finding the age at which the first massive galaxies appeared can constrain galaxy evolution theories. But this is not easy.

"Looking for the first examples of these massive star factories is like searching for a needle in a haystack; the Herschel dataset is extremely rich," says Dominik Riechers of Cornell University, who led the investigation.

Tens of thousands of massive, star-forming galaxies have been detected by Herschel as part of HerMES and sifting through them to find the most interesting ones is a challenge.

"This galaxy stands out because of its very red colour in the images taken with the UK-led SPIRE instrument" says co-investigator Mat Page (UCL Space and Climate Physics).

Red in this case means brightest at longer infrared wavelengths and, owing to the effect of redshift in our expanding Universe, this can indicate extreme distance. Follow-up observations with a suite of ground-based telescopes confirmed that HFLS3 was the most distant galaxy of its kind ever found, seen just 880 million years after the Big Bang, at redshift 6.34.

With this in hand, the astronomers were able to confidently translate the galaxy's infrared brightness into a star formation rate, discovering its extraordinary nature.

HFLS3 is making so many stars that it is called a 'maximum starburst'. The whole galaxy is wreathed in star formation, to the point where the intense radiation of the young stars almost blows away the star-forming material in the galaxy. Environments like this do not exist on galaxy-wide scales in the Universe today.

"Early starbursts like HFLS3 produced the heavy elements that made up later generations of stars and galaxies, and much of the matter we know today," says Dr Riechers.

Even in the early Universe, they are expected to be extremely rare. The mere existence of a single such object so early in the Universe poses a challenge to current theories of early galaxy formation, which predict that they should reach such large masses only much later.

The team are continuing to comb the enormous dataset from Herschel looking for more examples of such extreme, early galaxies.

"With these observations, Herschel has found a rare example of a galaxy bursting with stars at a time in cosmic history when there were very few such galaxies," says Goran Pilbratt, ESA's Herschel Project Scientist.

"This underlines the pioneering nature of Herschel and its ability to reveal a previously hidden Universe, improving our understanding of how galaxies form."

"A Dust-Obscured Massive Hyper-Starburst Galaxy at Redshift 6.34" by D. A. Riechers et al. is published in Nature, 18 April 2013.

.


Related Links
UCL Space and Climate Physics (Mullard Space Science Laboratory)
ESA Herschel Space Observatory
Mullard Space Science Laboratory Astrophysics Group
Stellar Chemistry, The Universe And All Within It






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





STELLAR CHEMISTRY
Supernova Remnant
Boston MA (SPX) Apr 19, 2013
This year, astronomers around the world have been celebrating the 50th anniversary of X-ray astronomy. Few objects better illustrate the progress of the field in the past half-century than the supernova remnant known as SN 1006. When the object we now call SN 1006 first appeared on May 1, 1006 A.D., it was far brighter than Venus and visible during the daytime for weeks. Astronomers in Chi ... read more


STELLAR CHEMISTRY
Characterizing The Lunar Radiation Environment

Russia rekindles Moon exploration program, intends setting up first human outposts there

Pre-existing mineralogy may survive lunar impacts

Lunar cycle determines hunting behaviour of nocturnal gulls

STELLAR CHEMISTRY
Accurate pointing by Curiosity

NASA Mars Orbiter Images May Show 1971 Soviet Lander

Opportunity is in position for solar conjunction at 'Cape York' on the rim of Endeavour Crater

NASA spacecraft may have spotted pieces of Soviet spacecraft on Mars

STELLAR CHEMISTRY
What makes a good astronaut?

NASA urged to preserve funding for planetary science missions

Testing Spacesuits in Antarctica, part 1

Obama's budget would boost science, health

STELLAR CHEMISTRY
Yuanwang III, VI depart for space-tracking missions

Shenzhou's Shadow Crew

Shenzhou 10 sent to launch site

China's Next Women Astronauts

STELLAR CHEMISTRY
Full tank, please For ATV Einstein

Russia puts mice, newts in space for a month

Cosmonaut becomes oldest person to walk in space, Russia ministry says

Mice "crew" of the Russian space satellite having troubles

STELLAR CHEMISTRY
NASA Seeks Innovative Suborbital Flight Technology Proposals

Stephane Israel named Chairman and CEO of Arianespace

Launch pad problem scrubs launch of Antares rocket for NASA

ILS Proton Launches Anik G1 for Telesat

STELLAR CHEMISTRY
Notre Dame astrophysicist discovers 5-planet system like Earth

Five-Planet System With Most Earth-Like Exoplanet Yet Found

New Techniques Allow Discovery Of Smallest Super-Earth Exoplanets

Kepler Finds Two Water Worlds 1200 Lights Years Away

STELLAR CHEMISTRY
Softening steel problem expands computer model applications

New material gets itself into shape

For the very first time, two spacecraft will fly in formation with millimeter precision

High pressure gold nanocrystal structure revealed




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement