Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Study sheds new light on early star formation in the universe

Study sheds new light on early star formation in the universe

September 14, 2007

A groundbreaking study has provided new insight into the way the first stars were formed at the start of the Universe, some 13 billion years ago.

Cosmologists from Durham University, publishing their results in the prestigious international academic journal, Science, suggest that the formation of the first stars depends crucially on the nature of 'dark matter', the strange material that makes up most of the mass in the universe.




The discovery takes scientists a step further to determining the nature of dark matter, which remains a mystery since it was first discovered more than 70 years ago. It also suggests that some of the very first stars that ever formed can still be found in the Milky Way galaxy today.

Early structure formation in the Universe involves interaction between elusive particles known as 'dark matter'. Even though little is known about their nature, evidence for the presence of dark matter is overwhelming, from observations of galaxies, to clusters of galaxies, to the Universe as a whole.

After the Big Bang, the universe was mostly 'smooth', with just small ripples in the matter density. These ripples grew larger due to the gravitational forces acting on the dark matter particles contained in them. Eventually, gas was pulled into the forming structures, leading to the formation of the very first stars, about 100 million years after the Big Bang.

For their research, the team from Durham University's Institute for Computational Cosmology carried out sophisticated computer simulations of the formation of these early stars with accepted scientific models of so-called 'cold' as well as 'warm' dark matter.

The computer model found that for slow moving 'cold dark matter' particles, the first stars formed in isolation, with just a single, larger mass star forming per developing spherical dark matter concentration.

In contrast, for faster-moving 'warm dark matter', a large number of stars of differing sizes formed at the same time in a big burst of star formation. The bursts occurred in long and thin filaments.

One of the researchers, Dr Liang Gao, who receives funding from the UK's Science and Technologies Facilities Council, said: "These filaments would have been around 9000 light years long, which is about a quarter of the size of the Milky Way galaxy today. The very luminous star burst would have lit-up the dark universe in spectacular fashion."

Stars forming in the cold dark matter are massive. The larger a star is, the shorter its life span, so these larger mass stars would not have survived until today. However the warm dark matter model predicts the formation of low mass stars as well as larger ones and the scientists say the low mass stars would survive until today.

The research paves the way for observational studies which could bring scientists closer to finding out more about the nature of dark matter. Co-researcher, Dr Tom Theuns, said: "A key question that astronomers often ask is 'where are the descendants of the first stars today"' The answer is that, if the dark matter is warm, some of these primordial stars should be lurking around our galaxy."

The Durham University scientists also give new insights into the way that black holes could be formed. Most galaxies harbour in their centres monster black holes, some with masses more than a billion times the mass of the sun.

The team hypothesises that collisions between stars in the dense filament in the warm dark matter scenario lead to the formation of the seeds for such black holes.

Dr Theuns added: "Our results raise the exciting prospect of learning about the nature of dark matter from studying the oldest stars. Another tell-tale sign could be the gigantic black holes that live in centres of galaxies like the Milky Way. They could have formed during the collapse of the first filaments in a universe dominated by warm dark matter."

Durham University



Related Dark Matter Current Events and Dark Matter News Articles Dark Matter Current Events and Dark Matter News RSS Dark Matter Current Events and Dark Matter News RSS
Memory mission explores new territory in neuroscience
Astrophysicists peer into the far corners of deep space for dark matter, but for neuroscientists at the Queensland Brain Institute (QBI) exploring the unknown is much closer to home.

Oak Ridge supercomputer is the world's fastest for science
A Cray XT high-performance computing system at the Department of Energy's (DOE) Oak Ridge National Laboratory is the world's fastest supercomputer for science.

New gene silencing pathway found in plants
Biologists at Washington University in St. Louis have made major headway in explaining a mechanism by which plant cells silence potentially harmful genes.

Giant simulation could solve mystery of 'dark matter'
The search for a mysterious substance which makes up most of the Universe could soon be at an end, according to new research.

Ghostly glow reveals galaxy clusters in collision
A team of scientists, including astronomers from the Naval Research Laboratory (NRL), have detected long wavelength radio emission from a colliding, massive galaxy cluster which, surprisingly, is not detected at the shorter wavelengths typically seen in these objects.

Listening to dark matter
A team of researchers in Canada have made a bold stride in the struggle to detect dark matter. The PICASSO collaboration has documented the discovery of a significant difference between the acoustic signals induced by neutrons and alpha particles in a detector based on superheated liquids.

Spallation Neutron Source sends first neutrons to 'Big Bang' beam line
New analytical tools coming on line at the Spallation Neutron Source, the Department of Energy's state-of-the-art neutron science facility at Oak Ridge National Laboratory, include a beam line dedicated to nuclear physics studies.

Scientists Detect Cosmic 'Dark Flow' Across Billions of Light Years
Using data from NASA's Wilkinson Microwave Anisotropy Probe (WMAP), scientists have identified an unexpected motion in distant galaxy clusters. The cause, they suggest, is the gravitational attraction of matter that lies beyond the observable universe.

First beam for Large Hadron Collider
An international collaboration of scientists today sent the first beam of protons zooming at nearly the speed of light around the world's most powerful particle accelerator-the Large Hadron Collider (LHC)-located at the CERN laboratory near Geneva, Switzerland.

First beam for Large Hadron Collider, world's mightiest particle accelerator
An international collaboration of scientists today sent the first beam of protons zooming at nearly the speed of light around the 17-mile-long underground circular path of the Large Hadron Collider (LHC), the world's most powerful particle accelerator, located at the CERN laboratory near Geneva, Switzerland.
More Dark Matter Current Events and Dark Matter News Articles


Dark Matters: Unifying Matter, Dark Matter, Dark Energy, and the Universal Grid
by Dr. Percy Seymour

One of the most important unsolved problems of current physics, astronomy, and cosmology is the nature of dark matter and dark energy. These two invisible components of the universe seem to control the behavior of galaxies, clusters of galaxies, and the accelerating expansion of the universe, but we do not know what they are. Dark Matters offers a unified explanation for dark matter and dark...



Dark Side of the Universe: Dark Matter, Dark Energy, and the Fate of the Cosmos
by Iain Nicolson

Once we thought the universe was filled with shining stars, dust, planets, and galaxies. We now know that more than 98 percent of all matter in the universe is dark. It emits absolutely nothing yet bends space and time; keeps stars speeding around galaxies; and determines the fate of the universe. But dark matter is only part of the story. Scientists have recently discovered that the expansion of...



In Search of Dark Matter (Springer Praxis Books / Space Exploration)
by Ken Freeman, Geoff McNamara

The dark matter problem is one of the most fundamental and profoundly difficult problems in the history of science. Not knowing what makes up most of the mass in the Universe goes to the heart of our understanding of the Universe and our place in it. In Search of Dark Matter is the story of the emergence of the dark matter problem, from the initial 'discovery' of dark matter by Jan Oort to...



Dark Matter: A Century of Speculative Fiction from the African Diaspora

Tapping into the science fiction, fantasy, and speculative fiction of black writers, "Dark Matter" introduces a world of talent to readers who have not yet realized the depth and breadth of these works -- and who in some cases do not even know that they exist. The first and only anthology of its kind, it contains stories published as early as 1887 through the most cutting-edge work of today,...



Dark Matter
by S. W. Ahmed

Dark matter constitutes the bulk of all matter in the known universe. Yet to this day, its true nature remains one of science's greatest mysteries. But what if dark matter actually is just ordinary matter purposely hidden from our view? What if we are only allowed to see a small fraction of the stars in every galaxy, because the vast majority of star systems in our own galaxy are teeming with...



Dark Matter, Dark Energy: The Dark Side of the Universe Course No. 1272

24 lectures, 30 minutes/lecture Taught by Sean Carroll California Institute of Technology Ph.D., Harvard University There's more to the universe than meets the eyea lot more. In recent years scientists have discovered that 95 percent of the contents of the cosmos are invisible to all of our current methods of direct detection. Yet they are definitely there: Something is holding galaxies and...



Dark Matter: Reading the Bones
by Sheree R. Thomas

Like its groundbreaking predecessor, DARK MATTER: Reading the Bones introduces black speculative fiction writers to readers who may not have realized the depth and breadth of these works. This anthology includes original short fiction and previously published works from Charles Johnson, the National Book Award-winning author of Middle Passage; Tananarive Due; Walter Mosley; W. E. B. Du Bois;...



Stella Brite and the Dark Matter Mystery
by Sara L. Latta



D20 Dark Matter (d20 Modern Supplement)
by Wolfgang Baur, Monte Cook

Fresh update to a favorite campaign setting. d20 Dark•Matter is a 160-page d20 Modern® supplement that updates the original Dark•Matter Campaign Setting (created for the Alternity® Science Fiction Roleplaying Game), making it fully compatible with the d20 Modern rules. It also includes some new content.d20 Dark•Matter presents a world where devious organizations scheme for world...

Dark Matters
by Roberto Aguirre-Sacasa

© 2008 BrightSurf.com