Featured Research

from universities, journals, and other organizations

Exceptionally Deep View Of Strange Galaxy

Date:
February 5, 2009
Source:
European Space Agency
Summary:
A spectacular new image of an unusual spiral galaxy in the Coma Galaxy Cluster has been created from data taken by the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope. It reveals fine details of the galaxy, NGC 4921, as well as an extraordinary rich background of more remote galaxies stretching back to the early Universe.

This very deep image taken with the NASA/ESA Hubble Space Telescope shows the spiral galaxy NGC 4921 along with a spectacular backdrop of more distant galaxies. It was created from a total of 80 separate pictures through yellow and near-infrared filters.
Credit: NASA, ESA, K. Cook (Lawrence Livermore National Laboratory, USA)

The Coma Galaxy Cluster, in the northern constellation of Coma Berenices, the hair of Queen Berenice, is one of the closest very rich collections of galaxies in the nearby Universe. The cluster, also known as Abell 1656, is about 320 million light-years from Earth and contains more than 1000 members.

The brightest galaxies, including NGC 4921 shown here, were discovered back in the late 18th century by William Herschel.

The galaxies in rich clusters undergo many interactions and mergers that tend to gradually turn gas-rich spirals into elliptical systems without much active star formation. As a result there are far more ellipticals and fewer spirals in the Coma Cluster than are found in quieter corners of the Universe.

NGC 4921 is one of the rare spirals in Coma, and a rather unusual one — it is an example of an "anaemic spiral" where the normal vigorous star formation that creates a spiral galaxy’s familiar bright arms is much less intense. As a result there is just a delicate swirl of dust in a ring around the galaxy, accompanied by some bright young blue stars that are clearly separated out by Hubble’s sharp vision. Much of the pale spiral structure in the outer parts of the galaxy is unusually smooth and gives the whole galaxy the ghostly look of a vast translucent jellyfish.

The long exposure times and sharp vision of Hubble also allowed it to not just image NGC 4921 in exquisite detail but also to see far beyond into the distant Universe. All around, and even through the galaxy itself, thousands of much more remote galaxies of all shapes, sizes and colours are visible. Many have the spotty and ragged appearance of galaxies at a time before the familiar division into spirals and ellipticals had become established.

The Hubble images used to make this picture were originally obtained by a team led by Kem Cook (Lawrence Livermore National Laboratory, California). The team was using Hubble to search for Cepheid variable stars in NGC 4921 that could be used to measure the distance to the Coma Cluster and hence the expansion rate of the Universe. Unfortunately the failure of the Advanced Camera for Surveys in early 2007 meant that they had insufficient data to complete their original programme, although they hope to continue after the servicing mission. Very deep imaging data like this, which is available to anyone from the Hubble archives, may also be used for other interesting scientific explorations of this galaxy and its surroundings.

This image was created from 50 separate exposures through a yellow filter and another 30 exposures through a near-infrared filter using the Wide Field Channel of the Advanced Camera for Surveys on Hubble. The total exposure times were approximately seventeen hours and ten hours respectively.


Story Source:

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


Cite This Page:

European Space Agency. "Exceptionally Deep View Of Strange Galaxy." ScienceDaily. ScienceDaily, 5 February 2009. <www.sciencedaily.com/releases/2009/02/090205083709.htm>.
European Space Agency. (2009, February 5). Exceptionally Deep View Of Strange Galaxy. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2009/02/090205083709.htm
European Space Agency. "Exceptionally Deep View Of Strange Galaxy." ScienceDaily. www.sciencedaily.com/releases/2009/02/090205083709.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