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




TIME AND SPACE
Black Holes Spin Faster And Faster
by Staff Writers
London, UK (SPX) May 24, 2011


An artist's impression of the jets emerging from a supermassive black hole at the centre of the galaxy PKS 0521-36. Credit: Dana Berry / STScI

Two UK astronomers have found that the giant black holes in the center of galaxies are on average spinning faster than at any time in the history of the Universe. Dr. Alejo Martinez-Sansigre of the University of Portsmouth and Prof. Steve Rawlings of the University of Oxford made the new discovery by using radio, optical and X-ray data. They publish their findings in the journal Monthly Notices of the Royal Astronomical Society.

There is strong evidence that every galaxy has a black hole in its center. These black holes have masses of between a million and a billion Suns and so are referred to as 'supermassive'.

They cannot be seen directly, but material swirls around the black hole in a so-called accretion disk before its final demise. That material can become very hot and emit radiation including X-rays that can be detected by space-based telescopes whilst associated radio emission can be detected by telescopes on the ground.

As well as radiation, twin jets are often associated with black holes and their accretion disks. There are many factors that can cause these jets to be produced, but the spin of the supermassive black hole is believed to be important. However, there are conflicting predictions about how the spins of the black holes should be evolving and until now this evolution was not well understood.

Dr. Martinez-Sansigre and Professor Rawlings compared theoretical models of spinning black holes with radio, optical and X-ray observations made using a variety of instruments and found that the theories can explain very well the population of supermassive black holes with jets.

Using the radio observations, the two astronomers were able to sample the population of black holes, deducing the spread of the power of the jets. By estimating how they acquire material (the accretion process) the two scientists could then infer how quickly these objects are spinning.

The observations also give information on how the spins of supermassive black holes have evolved. In the past, when the Universe was half its the present size, practically all of the supermassive black holes had very low spins, whereas nowadays a fraction of them have very high spins. So on average, supermassive black holes are spinning faster than ever before.

This is the first time that the evolution of the spin of the supermassive black holes has been constrained, and it suggests that those supermassive black holes that grow by swallowing matter will barely spin, while those that merge with other black holes will be left spinning rapidly.

Commenting on the new results, Dr. Martinez-Sansigre said: "The spin of black holes can tell you a lot about how they formed. Our results suggest that in recent times a large fraction of the most massive black holes have somehow spun up.

"A likely explanation is that they have merged with other black holes of similar mass, which is a truly spectacular event, and the end product of this merger is a faster spinning black hole."

Professor Rawlings adds: "Later this decade we hope to test our idea that these supermassive black holes have been set spinning relatively recently. Black hole mergers cause predictable distortions in space and time - so-called gravitational waves.

With so many collisions, we expect there to be a cosmic background of gravitational waves, something that will change the timing of the pulses of radio waves that we detect from the remnants of massive stars known as pulsars.

"If we are right, this timing change should be picked up by the Square Kilometre Array, the giant radio observatory due to start operating in 2019."

The results are published in the paper, "Observational constraints on the spin of the most massive black holes from radio observations", Martinez-Sansigre A., Rawlings S., Monthly Notices of the Royal Astronomical Society. Preprint available here.

.


Related Links
Royal Astronomical Society
Understanding Time and Space






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

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




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





TIME AND SPACE
Radio Telescopes Capture Best-Ever Snapshot of Black Hole Jets
Greenbelt MD (SPX) May 23, 2011
An international team, including NASA-funded researchers, using radio telescopes located throughout the Southern Hemisphere has produced the most detailed image of particle jets erupting from a supermassive black hole in a nearby galaxy. "These jets arise as infalling matter approaches the black hole, but we don't yet know the details of how they form and maintain themselves," said Corneli ... read more


TIME AND SPACE
Twin GRAIL Spacecraft to Launch Site by Lockheed Martin

A Wrinkly Old Reveal Clues To Its Past

MoonBots Challenges Teams to Conduct Lunar Missions with LEGO Robots

Earth's Nearest Neighbor Within Reach

TIME AND SPACE
Endeavour Crater Just Three Miles Away For Opportunity Mars Rover

Mars Rover Driving Leaves Distinctive Tracks

Opportunity Cracks The 18-Mile Mark

Mars Science Laboratory Aeroshell Delivered To Launch Site

TIME AND SPACE
Testing Spacesuits in Antarctica - Part 1

Which technologies get better faster

AIA Says US Human Spaceflight At Critical Juncture

NASA Denies Entry To Chinese Journalists For Shuttle Launch

TIME AND SPACE
Top Chinese scientists honored with naming of minor planets

China sees smooth preparation for launch of unmanned module

China to attempt first space rendezvous

Countdown begins for Chineses space station program

TIME AND SPACE
Expedition 27 Crew Undocks from Station

Astronauts to try spacewalk 'hokey pokey': NASA

ISS astronauts land safely in Kazakhstan: mission control

Pope makes first ever video call to astronauts in space

TIME AND SPACE
Russia sends two Soyuz carrier rockets to French Guiana

ILS Proton Successfully Launches Telstar 14R And Estrela do Sul 2 for Telesat

Satellites for Asia and India are orbited on Arianespace's third Ariane 5 mission of 2011

Taiwan, Singapore launch satellite

TIME AND SPACE
Kepler's Astounding Haul of Multiple-Planet Systems Just Keeps Growing

Bennett team discovers new class of extrasolar planets

Climate scientists reveal new candidate for first habitable exoplanet

Free-Floating Planets May be More Common Than Stars

TIME AND SPACE
Long-delayed Duke Nukem videogame hits in June

Microsoft unveils Windows Phone update 'Mango'

Better buildings for extreme climates will be focus of researcher talk

Foxconn polishing plants in China closed after blast




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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