Nav: Home

Baby galaxies grew up quickly

May 16, 2012

Baby galaxies from the young Universe more than 12 billion years ago evolved faster than previously thought, shows new research from the Niels Bohr Institute. This means that already in the early history of the Universe, there was potential for planet formation and life. The research results have been published in the scientific journal, Monthly Notices of the Royal Astronomical Society Letters.

For several thousand years after the Big Bang 13.7 billion years ago, the Universe consisted of a hot, dense primordial soup of gases and particles. But the Universe was expanding rapidly and the primordial soup became less dense and cooled. However, the primordial soup was not evenly distributed, but was denser in some areas than others. The density in some of the densest areas increased due to gravity and began to contract, forming the first stars and galaxies. This took place approximately 500 million years after the Big Bang.

The earliest galaxies were probably comprised of primitive, giant stars that consisted of only hydrogen and helium. There were no heavier elements. They first appeared later in the evolution of the Universe, created by nuclear processes in the stars.

Cosmic cycle

A star is a giant ball of glowing gas that produces energy by fusing hydrogen and helium into heavier and heavier elements. When no more energy can be extracted the star dies and massive clouds of dust and gas are flung out into space. These large clouds are condensed and recycled into new stars in a gigantic cosmic cycle. The new stars that are formed will have a higher content of heavier elements than the previous and for each generation of star formation there are more and more of the heavy elements and metals. And heavy elements (especially carbon and oxygen) are necessary for the formation of planets and life, as we know it.

Up until now, researchers thought that it had taken billions of years for stars to form and with that, galaxies with a high content of elements heavier than hydrogen and helium. But new research from the Niels Bohr Institute shows that this process went surprisingly quickly in some galaxies.

"We have studied 10 galaxies in the early Universe and analysed their light spectra. We are observing light from the galaxies that has been on a 10-12 billion year journey to Earth, so we see the galaxies as they were then. Our expectation was that they would be relatively primitive and poor in heavier elements, but we discovered somewhat to our surprise that the gas in some of the galaxies and thus the stars in them had a very high content of heavier elements. The gas was just as enriched as our own Sun," explains Professor Johan Fynbo from the Dark Cosmology Centre at the Niels Bohr Institute, University of Copenhagen.

Lighthouses of the Universe

The galaxies are so far away that you normally do not have the opportunity to observe them directly, but the researchers have used a special method.

"There are some extreme objects in the Universe called quasars. Quasars are gigantic black holes that are active and when matter falls into them, they emit light that is as strong as thousands of galaxies. They are like a kind of lighthouse that lights up in the Universe and can be seen very far away," explains Jens-Kristian Krogager, PhD student at the Dark Cosmology Centre at the Niels Bohr Institute, University Copenhagen. He explains that in order to use quasars as light sources the quasar must lie behind the galaxy you want to observe.

"We then look at the light from the quasar and can see that some light is missing. The missing quasar light in the image has been absorbed by the chemical elements in the galaxy in front of it. By analysing the spectral lines we can see which elements there are and by measuring the strength of each line we can see the amount of the elements," explains Jens-Kristian Krogager.

Life in the early Universe

They discovered not only that the galaxies from the very early Universe had a surprisingly large quantity of heavier elements, but also that one of the galaxies in particular was especially interesting.

"For one of the galaxies, we observed the outer regions and here there was also a high element content. This suggests that large parts of the galaxy are enriched with a high content of heavier elements and that means that already in the early history of the Universe there was potential for planet formation and life," says Johan Fynbo.

-end-

http://www.nbi.ku.dk/english/news/news11/baby_galaxies_grew_up_quickly/

http://onlinelibrary.wiley.com/doi/10.1111/j.1745-3933.2012.01272.x/abstract

For further information:
Jens-Kristian Krogager, Astrophysicist, Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, +45 3139-5099, krogager@dark-cosmology.dk
Johan Fynbo, Professor, Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, +45 3532-5983, +45 2875-5983, jfynbo@dark-cosmology.dk

University of Copenhagen
Paving the way for hydrogen fuel cells
The hype around hydrogen fuel cells has died down, but scientists have continued to pursue new technologies that could enable such devices to gain a firmer foothold.
Keeping the hydrogen coming
A coating of molybdenum improves the efficiency of catalysts for producing hydrogen.
Hydrogen bonds directly detected for the first time
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope.
Argon is not the 'dope' for metallic hydrogen
Hydrogen is both the simplest and the most-abundant element in the universe, so studying it can teach scientists about the essence of matter.
Metallic hydrogen, once theory, becomes reality
Nearly a century after it was theorized, Harvard scientists have succeeded in creating metallic hydrogen.
From theory to reality: The creation of metallic hydrogen
For more than 80 years, it has been predicted that hydrogen will adopt metallic properties under certain conditions, and now researchers have successfully demonstrated this phenomenon.
Artificial leaf goes more efficient for hydrogen generation
A new study, affiliated with Ulsan National Institute of Science and Technology has introduced a new artificial leaf that generates hydrogen, using the power of the Sun to mimic underwater photosynthesis.
Hydrogen from sunlight -- but as a dark reaction
The storage of photogenerated electric energy and its release on demand are still among the main obstacles in artificial photosynthesis.
New process produces hydrogen at much lower temperature
Waseda University researchers have developed a new method for producing hydrogen, which is fast, irreversible, and takes place at much lower temperature using less energy.
Hydrogen in your pocket? New plastic for carrying and storing hydrogen
A Waseda University research group has developed a polymer which can store hydrogen in a light, compact and flexible sheet, and is safe to touch even when filled with hydrogen gas.

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.

Now Playing: Radiolab

Truth Trolls
Today, a third story of folks relentlessly searching for the truth. But this time, the truth seekers are an unlikely bunch... internet trolls.


Now Playing: TED Radio Hour

Rethinking School
For most of modern history, humans have placed smaller humans in institutions called schools. But what parts of this model still work? And what must change? This hour, TED speakers rethink education.TED speakers include teacher Tyler DeWitt, social entrepreneur Sal Khan, international education expert Andreas Schleicher, and educator Linda Cliatt-Wayman.