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.”
Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung
High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences
24.10.2016 | Physics and Astronomy