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




STELLAR CHEMISTRY
Fat or flat: getting galaxies into shape
by Staff Writers
Perth, Australia (SPX) Mar 04, 2014


File image.

Australian astronomers have discovered what makes some spiral galaxies fat and bulging while others are flat discs - and it's all about how fast they spin. The research, led by the International Centre for Radio Astronomy Research (ICRAR) in Perth, found that fast-rotating spiral galaxies are flat and thin while equally sized galaxies that rotate slowly are fatter.

The study was published in the prestigious Astrophysical Journal and was part of "The Evolving Universe" research theme of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO). ICRAR Research Associate Professor Danail Obreschkow, from The University of Western Australia, said it is a much-debated mystery why galaxies look so different to each other.

"Some galaxies are very flat discs of stars and others are more bulging or even spherical," he said.

"Much of the last century of research has been dedicated to understanding this diversity of galaxies in the Universe and with this paper we've made a step towards understanding how this came about by showing that the rotation of spiral galaxies is a key driver for their shape."

The study looked at 16 galaxies - all between 10 million and 50 million light years from Earth - using data from a survey called THINGS.

"The THINGS survey shows you the cold gas in the galaxies, not only where it is but how it moves," Dr Obreschkow said.

"That's a crucial point if you want to measure the spin, you can't just take a photograph, you have to take a special picture that shows you the motion."

Dr Obreschkow said the shape of a spiral galaxy is determined by both its spin and its mass and if you leave a galaxy on its own for billions of years both quantities will stay the same.

He said the way galaxies are formed looks a bit similar to a carousel made of an elastic disc.

"If the carousel is at rest, the elastic disc is quite small," Dr Obreschkow said.

"But when the whole thing is spinning the elastic disc becomes larger because it's feeling the effects of centrifugal force."

Our own Milky Way is a relatively flat disc with only a small bulge, the shape of which can be seen in the night sky.

"The white band of the Milky Way across the sky is a relatively thin band of constant thickness. However when you look right at the centre near the Sagittarius constellation you can actually see a thickening of the Milky Way, which is the bulge," Dr Obreschkow said.

He and co-author, Swinburne University Professor Karl Glazebrook, were able to measure the effect of spin on galaxies more than ten times better than anyone previously.

The study used data collected at the Karl G. Jansky Very Large Array in the United States, one of the most famous radio telescopes in the world and a significant pathfinder for the Square Kilometre Array.

"Fundamental Mass-Spin-Morphology Relation of Spiral Galaxies" The Astrophysical Journal, 28/2/2014.

.


Related Links
International Centre for Radio Astronomy Research
Stellar Chemistry, The Universe And All Within It






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





STELLAR CHEMISTRY
Closest, brightest supernova in decades is also a little weird
Berkeley CA (SPX) Mar 03, 2014
A bright supernova discovered only six weeks ago in a nearby galaxy is provoking new questions about the exploding stars that scientists use as their main yardstick for measuring the universe. Called SN 2014J, the glowing supernova was discovered by a professor and his students in the United Kingdom on Jan. 21, about a week after the stellar explosion first became visible as a pinprick of ... read more


STELLAR CHEMISTRY
China's Lunar Lander Still Operational

China Focus: Uneasy rest begins for China's troubled Yutu rover

Is Yutu Stuck?

Japan's Pocari Sweat bound for the moon: maker

STELLAR CHEMISTRY
NASA's Curiosity Mars Rover Views Striated Ground

NASA Mars Orbiter Views Opportunity Rover on Ridge

Curiosity Adds Reverse Driving for Wheel Protection

Curiosity Drives On After Crossing Martian Dune

STELLAR CHEMISTRY
Last Shuttle Commander Virtually Flies Boeing CST-100 to ISS

DARPA Open Catalog Makes Agency-Sponsored Software and Publications Available to All

India unveils its own astronaut crew capsule, plans test launch

Orion Underway Recovery Testing Begins off the Coast of California

STELLAR CHEMISTRY
The Next Tiangong

No Call for Yutu

What's up, Yutu

China's Jade Rabbit rover comes 'back to life'

STELLAR CHEMISTRY
Cosmonauts on space station to turn teacher for Russian students

NASA says US-Russia space ties 'normal'

Cancer Targeted Treatments from Space Station Discoveries

Space suit leak happened before, NASA admits

STELLAR CHEMISTRY
Russia to Start Building New Manned Rocket Launch Pad in 2015

New Vostochny space center a key priority for Russian Far East

'Mission of Firsts' Showcased New Range-Safety Technology at NASA Wallops

First Copernicus satellite at launch site

STELLAR CHEMISTRY
Kepler Mission Announces a Planet Bonanza, 715 New Worlds

Water is Detected in a Planet Outside Our Solar System

NASA cries planetary 'bonanza' with 715 new worlds

Detection of Water Vapor in the Atmosphere of a Hot Jupiter

STELLAR CHEMISTRY
ADS builds 'space furnace' to test materials of the future on the ISS

Big Mechanism Seeks the "Whys" Hidden in Big Data

Science publisher fooled by gibberish papers

Penn Researchers 'Design for Failure' With Model Material




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.