Subscribe free to our newsletters via your
. 24/7 Space News .

Universe breaks its fever
by Staff Writers
Melbourne, Australia (SPX) May 22, 2014

An animation of the Universe's 'fever' breaking: As the UV light from powerful quasars ionizes the helium in the intergalactic medium, the gas heats up. But when all the helium is ionized, the quasar light can no longer heat the gas; it passes straight through and the gas begins to cool down as the Universe expands.

An international team, led by researchers from Swinburne University of Technology, has found evidence that the Universe broke its rising 'fever' about 11 billion years ago. They measured the temperature of the Universe when it was 3 to 4 billion years old by studying the gas in between galaxies - the intergalactic medium. During these early years of the Universe's development, many extremely active galaxies were 'switching on' for the first time and heating their surroundings.

"However, 11 billion years ago, this fever seems to have broken and the Universe began cooling down again," lead researcher Elisa Boera, a PhD student from Swinburne's Centre for Astrophysics and Supercomputing, said.

"The intergalactic medium is an excellent recorder of the Universe's history. It retains memory of the big events that affected its properties, such as temperature and composition, during its different phases of evolution."

An earlier study found that the Universe caught this fever early in its history. Its authors used a new 'thermometer' - the imprint left on the light by the intergalactic medium as it travelled to Earth from distant, extremely bright objects called quasars.

In the new study, Ms Boera collected the bluest light that Earth's atmosphere transmits - harsh ultraviolet (UV) light from 60 quasars - and used the same method as the earlier study. This UV light comes from slightly later in the Universe's development, allowing the new temperature measurement.

"The quasar light suggests that the Universe had cooled by about 1000 degrees C within 1 billion years after reaching its maximum of 13,000 degrees," Ms Boera said.

"This cooling trend has probably continued to the present day."

Why did the Universe's fever break?
"We think the answer is helium," co-author of the new study Swinburne Associate Professor Michael Murphy said.

"Fourteen per cent of the intergalactic gas is helium and, 12 billion years ago, it was absorbing the intense radiation from active galaxies, losing electrons in the process.

"The electrons whizz around, heating up the gas. It's similar to the greenhouse effect on Earth: Carbon dioxide gas absorbs infrared radiation and heats our atmosphere.

"Once all the helium was ionized, the radiation would simply pass through the gas without heating it.

"Then, as the Universe expands the gas cools down, just like the cold gas sprayed from an aerosol can - it quickly cools as it expands out of the can."

The study has been published in the Monthly Notices of the Royal Astronomical Society.


Related Links
Swinburne's Centre for Astrophysics and Supercomputing
Understanding Time and Space

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

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

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

Tricking the Uncertainty Principle
Pasadena CA (SPX) May 20, 2014
Today, we are capable of measuring the position of an object with unprecedented accuracy, but quantum physics and the Heisenberg uncertainty principle place fundamental limits on our ability to measure. Noise that arises as a result of the quantum nature of the fields used to make those measurements imposes what is called the "standard quantum limit." This same limit influences both the ul ... read more

LRO View of Earth

Saturn in opposition tonight, will appear next to the moon

Russia to begin Moon colonization in 2030

Astrobotic Partners With NASA To Develop Robotic Lunar Landing Capability

Mars Curiosity rover may have transported Earth bacteria to Mars

NASA Rover Gains Martian Vista From Ridgeline

Opportunity Explores Region of Aluminum Clay Minerals

Mars mineral could be linked to microbes

Pay and go: 'Soyuz' space ticket at US$45-50 million

Staying alive: Rescue mission for disco-era satellite

Airbus design of European service module for Orion approved by ESA

Swiss Space Systems launch the ZeroG experience

Moon rover Yutu comes closer to public

The Phantom Tiangong

New satellite launch center to conduct joint drill

China issues first assessment on space activities

US Senate panel budgets $100 mn for non-Russian rocket

Scientists Seek Answers With Space Station Thyroid Cancer Study

New ISS Expedition Unaffected by Proton Crash

US-Russian Tensions Roiling Outer Space Cooperation

Halting Russian rocket engine deliveries may cost US $5 billion

India To Launch PSLV On Commercial Mission

Third-stage engine glitch causes Proton-M accident

Russia's Roscosmos plans to launch two more Protons this year

Starshade Could Help Photograph Distant Planets

Giant telescope tackles orbit and size of exoplanet

Odd planet, so far from its star

New Exomoon Hunting Technique Could Find Solar System-like Moons

MIPT Experts Reveal the Secret of Radiation Vulnerability

Russian space agency to create equipment for monitoring space debris

Spiders spin possible solution to 'sticky' problems

Is there really cash in your company's trash?

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.