Featured Research

from universities, journals, and other organizations

Old Galaxies Stick Together In The Young Universe

Date:
April 4, 2008
Source:
Royal Astronomical Society
Summary:
Using the most sensitive images ever obtained with the United Kingdom Infra-Red Telescope, astronomers have found convincing evidence that galaxies which look old early in the history of the Universe reside in enormous clouds of invisible dark matter and will eventually evolve into the most massive galaxies that exist in the present day.

The white arrows point to a few of the old, massive galaxies at a distance of 10 billion light years, discovered in the UKIDSS Ultra-Deep survey. This cut-out image represents just 1/150th of the full survey.
Credit: UKIDSS UDS survey team

Using the most sensitive images ever obtained with the United Kingdom Infra-Red Telescope (UKIRT), astronomers have found convincing evidence that galaxies which look old early in the history of the Universe reside in enormous clouds of invisible dark matter and will eventually evolve into the most massive galaxies that exist in the present day.

University of Nottingham PhD student Will Hartley, who led the study, described this research at the RAS National Astronomy Meeting in Belfast on Tuesday 1 April.

The distant galaxies identified in the UKIRT images are considered elderly because they are rich in old, red stars.  However, because the light from these systems has taken up to 10 billion years to reach Earth, they are seen as they appeared in the very early Universe, just 4 billion years after the Big Bang. The presence of such fully evolved galaxies so early in the life of the cosmos is hard to explain and has been a major puzzle to astronomers studying how galaxies form and evolve.

Hartley and collaborators used the deep UKIRT images to estimate the mass of the dark matter surrounding the old galaxies by measuring how strongly the galaxies cluster together.  All galaxies are thought to form within massive halos of dark matter which collapse under their own gravity from a smooth distribution of matter after the Big Bang.

These halos are invisible to normal telescopes but their mass can be estimated through analysis of galaxy clustering.

Hartley explains "Luckily, even if we don't know what dark matter is, we can understand how gravity will affect it and make it clump together. We can see that the old, red galaxies clump together far more strongly than the young, blue galaxies, so we know that their invisible dark matter halos must be more massive.”

The halos surrounding the old galaxies in the early Universe are found to be extremely massive, containing material which is one hundred thousand billion times the mass of our Sun.  In the nearby Universe, halos of this size are known to contain giant elliptical galaxies, the largest galaxies known.

"This provides a direct link to the present day Universe," says Hartley, "and tell us that these distant old galaxies must evolve into the most massive but more familiar elliptical-shaped galaxies we see around us today.  Understanding how these enormous elliptical galaxies formed is one of the biggest open questions in modern astronomy and this is an important step in comprehending their history."


Story Source:

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


Cite This Page:

Royal Astronomical Society. "Old Galaxies Stick Together In The Young Universe." ScienceDaily. ScienceDaily, 4 April 2008. <www.sciencedaily.com/releases/2008/04/080401160020.htm>.
Royal Astronomical Society. (2008, April 4). Old Galaxies Stick Together In The Young Universe. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2008/04/080401160020.htm
Royal Astronomical Society. "Old Galaxies Stick Together In The Young Universe." ScienceDaily. www.sciencedaily.com/releases/2008/04/080401160020.htm (accessed September 2, 2014).

Share This




More Space & Time News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: NASA Captures Solar Flare

Raw: NASA Captures Solar Flare

AP (Sep. 1, 2014) — NASA reported the sun emitted a mid-level solar flare, on August 24th. NASA's Solar Dynamics Observatory captured the images of the flare, which erupted on the left side of the sun. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Space Shuttle Discovery's Legacy, 30 Years Later

Space Shuttle Discovery's Legacy, 30 Years Later

Newsy (Aug. 30, 2014) — The space shuttle Discovery launched for the very first time 30 years ago. Here's a look back at its legacy. Video provided by Newsy
Powered by NewsLook.com
Experiment Tests Whether Universe Is Actually A Hologram

Experiment Tests Whether Universe Is Actually A Hologram

Newsy (Aug. 27, 2014) — Researchers at Fermilab are using a device called "The Holometer" to test whether our universe is actually a 2-D hologram that just seems 3-D. Video provided by Newsy
Powered by NewsLook.com
SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) — The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. Video provided by Newsy
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