Featured Research

from universities, journals, and other organizations

Dark Matter Disk In Our Galaxy, Supercomputer Simulation Shows

Date:
September 16, 2008
Source:
Royal Astronomical Society (RAS)
Summary:
The Milky Way contains a disk of "dark matter," according to new calculations by astronomers.They have used the results of a supercomputer simulation to deduce the presence of this disk.

A composite image of the dark matter disk (red contours) and the Atlas image mosaic of the Milky Way obtained as part of the Two Micron All Sky Survey (2MASS).
Credit: J. Read and O. Agertz

An international team of scientists predict that our Galaxy, the Milky Way, contains a disk of ‘dark matter’. Astronomers Dr Justin Read, Professor George Lake and Oscar Agertz of the University of Zurich, and Dr Victor Debattista of the University of Central Lancashire use the results of a supercomputer simulation to deduce the presence of this disk.

Related Articles


They explain how it could allow physicists to directly detect and identify the nature of dark matter for the first time.

Unlike the familiar ‘normal’ matter that makes up stars, gas and dust, ‘dark’ matter is invisible but its presence can be inferred through its gravitational influence on its surroundings. Physicists believe that it makes up 22% of the mass of the Universe (compared with the 4% of normal matter and 74% comprising the mysterious ‘dark energy’). But, despite its pervasive influence, no-one is sure what dark matter consists of.

Prior to this work, it was thought that dark matter forms in roughly spherical lumps called ‘halos’, one of which envelopes the Milky Way. But this ‘standard’ theory is based on supercomputer simulations that model the gravitational influence of the dark matter alone. The new work includes the gravitational influence of the stars and gas that also make up our Galaxy.

Stars and gas are thought to have settled into disks very early on in the life of the Universe and this affected how smaller dark matter halos formed. The team’s results suggest that most lumps of dark matter in our locality merged to form a halo around the Milky Way. But the largest lumps were preferentially dragged towards the galactic disk and were then torn apart, creating a disk of dark matter within the Galaxy.

“The dark disk only has about half of the density of the dark matter halo, which is why no one has spotted it before,” said lead author Justin Read. “However, despite its low density, if the disk exists it has dramatic implications for the detection of dark matter here on Earth.”

The Earth and Sun move at some 220 kilometres per second along a nearly circular orbit about the centre of our Galaxy. Since the dark matter halo does not rotate, from an Earth-based perspective it feels as if we have a ‘wind’ of dark matter flowing towards us at great speed. By contrast, the ‘wind’ from the dark disk is much slower than from the halo because the disk co-rotates with the Earth.

“It's like sitting in your car on the highway moving at a hundred kilometres an hour”, said team member Dr Victor Debattista. “It feels like all of the other cars are stationary because they are moving at the same speed.”

This abundance of low-speed dark matter particles could be a real boon for researchers because they are more likely to excite a response in dark matter detectors than fast-moving particles. “Current detectors cannot distinguish these slow moving particles from other background ‘noise’,” said Prof. Laura Baudis, a collaborator at the University of Zurich and one of the lead investigators for the XENON direct detection experiment, which is located at the Gran Sasso Underground Laboratory in Italy. “But the XENON100 detector that we are turning on right now is much more sensitive. For many popular dark matter particle candidates, it will be able to see something if it’s there.”

This new research raises the exciting prospect that the dark disk – and dark matter – could be directly detected in the very near future.


Story Source:

The above story is based on materials provided by Royal Astronomical Society (RAS). Note: Materials may be edited for content and length.


Journal Reference:

  1. J. I. Read, G. Lake, O. Agertz and Victor P. Debattista. Thin, thick and dark discs in %u039BCDM. Monthly Notices of the Royal Astronomical Society: Letters, Volume 389 Issue 3, Pages 1041 - 1057 DOI: 10.1111/j.1365-2966.2008.13643.x

Cite This Page:

Royal Astronomical Society (RAS). "Dark Matter Disk In Our Galaxy, Supercomputer Simulation Shows." ScienceDaily. ScienceDaily, 16 September 2008. <www.sciencedaily.com/releases/2008/09/080915210506.htm>.
Royal Astronomical Society (RAS). (2008, September 16). Dark Matter Disk In Our Galaxy, Supercomputer Simulation Shows. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2008/09/080915210506.htm
Royal Astronomical Society (RAS). "Dark Matter Disk In Our Galaxy, Supercomputer Simulation Shows." ScienceDaily. www.sciencedaily.com/releases/2008/09/080915210506.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Space & Time News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
Crowdfunded Moon Mission Offers To Store Your Digital Memory

Crowdfunded Moon Mission Offers To Store Your Digital Memory

Newsy (Nov. 19, 2014) Lunar Mission One is offering to send your digital memory (or even your DNA) to the moon to be stored for a billion years. Video provided by Newsy
Powered by NewsLook.com
Accidents Ignite Debate on US Commercial Space Travel

Accidents Ignite Debate on US Commercial Space Travel

AFP (Nov. 19, 2014) Serious accidents with two US commercial spacecraft within a week of each-other in October have re-ignited the debate over the place of private corporations in the exploration of space. Duration: 02:08 Video provided by AFP
Powered by NewsLook.com
Lunar Mission One Could Send Your Hair to The Moon

Lunar Mission One Could Send Your Hair to The Moon

Buzz60 (Nov. 19, 2014) A British-led venture called Lunar Mission One plans to send a module to the moon with keepsakes from Earth. Vanessa Freeman (@VanessaFreeTV) tells you how to get your photos and DNA onboard. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins