Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


First Direct Detection Sheds Light on Dark Galaxies

Most people think of galaxies as huge islands of stars, gas and dust that populate the universe in visual splendor. Theory, however, has predicted there are other types of galaxies that are devoid of stars and made predominately of dense gas. These “dark” galaxies would be unseen against the black backdrop of the universe.
Now, an international team of astronomers has detected several dark galaxies by observing the fluorescent glow of their hydrogen gas, illuminated by the ultraviolet light of a nearby quasar. But what exactly are dark galaxies, and what role do they play in the evolution of our universe?

“Dark galaxies are composed of dark matter and gas, but for some reason they have not been able to form stars,” said Martin Haehnelt, Kavli Institute for Cosmology at the University of Cambridge. “Some theoretical models have predicted that dark galaxies were common in the early universe when galaxies had more difficulty forming stars – partly because their density of gas was not sufficient to form stars – and only later did galaxies begin to ignite stars, becoming like the galaxies we see today.”

Haehnelt is a member of the scientific team that detected these galaxies. According to Haehnelt, one can begin to understand the importance of dark galaxies by looking at our own Milky Way. “We expect the precursor to the Milky Way was a smaller bright galaxy that merged with dark galaxies nearby. They all came together to form our Milky Way that we see today.”

Another member of the team, Sebastiano Cantalupo of the University of California, Santa Cruz, agreed that dark galaxies are the building blocks of modern galaxies. “In our current theory of galaxy formation, we believe that big galaxies form from the merger of smaller galaxies. Dark galaxies bring to big galaxies a lot of gas, which then accelerates star formation in the bigger galaxies.”

The techniques used for detecting dark galaxies also may provide a new way to learn about other phenomena in the universe, including what some call the “cosmic web” – unseen filaments of gas and dark matter believed to permeate the universe, feeding and building galaxies and galaxy clusters where the filaments intersect.

“I wonder if we can indeed use this technique to see the emission of filamentary gas in the cosmic web, and if so, how close are we to seeing that?” said team member Simon Lilly of the Swiss Federal Institute of Technology in Zurich, Switzerland. “That has been something of a Holy Grail for many, many years and I think this most recent discovery of dark galaxies is a significant step toward the goal.”

The complete discussion with Drs. Haehnelt, Cantalupo and Lilly can be found at:

James Cohen | Newswise Science News
Further information:

Further reports about: Dark Quencher Detection LIGHT Milky Way building block dark matter galaxies galaxy cluster

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

Im Focus: New Products - Highlights of COMPAMED 2016

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...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>