Featured Research

from universities, journals, and other organizations

Substructure Maps Show That Dark Matter Clumps In Galaxies

Date:
January 19, 2005
Source:
Yale University
Summary:
Hubble Space Telescope data, analyzed by a Yale astronomer using gravitational lensing techniques, has generated a spatial map demonstrating the clumped substructure of dark matter inside clusters of galaxies.

Gravitational lensing image of galaxies (yellow to red) and haloes from clumped dark matter (blue).
Credit: Image courtesy of Yale University

New Haven, Conn. -- Hubble Space Telescope data, analyzed by a Yale astronomer using gravitational lensing techniques, has generated a spatial map demonstrating the clumped substructure of dark matter inside clusters of galaxies.

Clusters of galaxies (about a million, million times the mass of our sun), are typically made up of hundreds of galaxies bound together by gravity. About 90 percent of their mass is dark matter. The rest is ordinary atoms in the form of hot gas and stars.

Although little is known about it, cold dark matter is thought to have structure at all magnitudes. Theoretical models of the clumping properties were derived from detailed, high resolution simulations of the growth of structure in the Universe. Although previous evidence supported the "concordance model" of a Universe mostly composed of cold, dark matter, the predicted substructure had never been detected.

In this study, Yale assistant professor of astronomy and physics Priyamvada Natarajan and her colleagues demonstrate that, at least in the mass range of typical galaxies in clusters, there is an excellent agreement between the observations and theoretical predictions of the concordance model.

Using gravitational lensing made it possible for the observers to visualize light from distant galaxies as it bent around mass in its way. This allowed the researchers to measure light deflections that indicated structural clumps in the dark matter.

"We used an innovative technique to pick up the effect of precisely the clumps which might otherwise be obscured by the presence of more massive structures," said Natarajan. "When we compared our results with theoretical expectations of the concordance model, we found extremely good agreement, suggesting that the model passes the substructure test for the mass range we are sensitive to with this technique."

"We think the properties of these clumps hold a key to the nature of dark matter -- which is presently unknown," said Natarajan. "The question remains whether these predictions and observations agree for smaller mass clumps that are as yet undetected."

Co-author on the study, funded by Yale University, is Volker Springel, MPA, Garching, Germany. Other collaborators include.Jean-Paul Kneib, LAM - OAMP, Marseille, France, Ian Smail, University of Durham, U.K., and Richard Ellis of Caltech.

###

Citation: Astrophysical Journal Letters 617: L13-L16 (December 10, 2004)

Priyamvada Natarajan: http://www.astro.yale.edu/priya/

Astronomy: http://www.astro.yale.edu/

Physics: http://www.physics.yale.edu/


Story Source:

The above story is based on materials provided by Yale University. Note: Materials may be edited for content and length.


Cite This Page:

Yale University. "Substructure Maps Show That Dark Matter Clumps In Galaxies." ScienceDaily. ScienceDaily, 19 January 2005. <www.sciencedaily.com/releases/2005/01/050110122618.htm>.
Yale University. (2005, January 19). Substructure Maps Show That Dark Matter Clumps In Galaxies. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2005/01/050110122618.htm
Yale University. "Substructure Maps Show That Dark Matter Clumps In Galaxies." ScienceDaily. www.sciencedaily.com/releases/2005/01/050110122618.htm (accessed August 21, 2014).

Share This




More Space & Time News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space to Ground: Hello Georges

Space to Ground: Hello Georges

NASA (Aug. 18, 2014) Europe's ATV-5 delivers new science and the crew tests smart SPHERES. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, August 15, 2014

This Week @ NASA, August 15, 2014

NASA (Aug. 15, 2014) Carbon Observatory’s First Data, ATV-5 Delivers Cargo, Cygnus Departs Station and more... Video provided by NASA
Powered by NewsLook.com
Space Shuttle Replica Hoisted for Landmark Exhibit

Space Shuttle Replica Hoisted for Landmark Exhibit

Reuters - US Online Video (Aug. 14, 2014) The space shuttle replica Independence has been hoisted atop Space Center Houston's shuttle carrier aircraft, creating a monument to the shuttle program which will open to the public next year. Rough Cut (no reporter narration). Video provided by Reuters
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:
from the past week

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