Featured Research

from universities, journals, and other organizations

Split-personality elliptical galaxy holds a hidden spiral

Date:
October 22, 2012
Source:
Harvard-Smithsonian Center for Astrophysics
Summary:
Most big galaxies fit into one of two camps: pinwheel-shaped spiral galaxies and blobby elliptical galaxies. Spirals like the Milky Way are hip and happening places, with plenty of gas and dust to birth new stars. Ellipticals are like cosmic retirement villages, full of aging residents in the form of red giant stars. Now, astronomers have discovered that one well-known elliptical has a split personality. Centaurus A is hiding a gassy spiral in its center.

The giant elliptical galaxy M87 shows a split personality because it hides a gaseous spiral at its core. When M87 collided with a spiral galaxy 300 million years ago, it slurped up the spiral's gases, which formed a new spiral inside the larger galaxy.
Credit: ESO

Most big galaxies fit into one of two camps: pinwheel-shaped spiral galaxies and blobby elliptical galaxies. Spirals like the Milky Way are hip and happening places, with plenty of gas and dust to birth new stars. Ellipticals are like cosmic retirement villages, full of aging residents in the form of red giant stars. Now, astronomers have discovered that one well-known elliptical has a split personality. Centaurus A is hiding a gassy spiral in its center.

"No other elliptical galaxy is known to have spiral arms," said lead author Daniel Espada (National Astronomical Observatory of Japan & Harvard-Smithsonian Center for Astrophysics). "Centaurus A may be an old galaxy, but it's still very young at heart."

Centaurus A isn't your typical elliptical to begin with. Its most striking feature is a dark dust lane across its middle -- a sign that it swallowed a spiral galaxy about 300 million years ago.

Centaurus A slurped that galaxy's gases down, forming a disk that we see nearly edge on. From our point of view, any features in that disk have been hidden by the intervening dust.

To tease out the disk's structure, Espada and his colleagues used the sharp vision of the Smithsonian's Submillimeter Array. This radio telescope can see through dust to pick up signals from naturally occurring carbon monoxide gas. By mapping the gas, the team unveiled two distinct spiral arms within the galaxy's core.

These gaseous tendrils have sizes and shapes similar to spiral arms in galaxies like the Milky Way. Also like the Milky Way's spiral arms, they are forming new generations of stars.

"Centaurus A has been given a new lease on life by that past merger," said Espada.

Computer simulations suggest that the spiral features might endure for hundreds of millions of years to come.

Although Centaurus A is the first elliptical galaxy found to have spiral arms, it may not be the last. Since it's only 12 million light-years away, it's relatively nearby and easy to study. The Atacama Large Millimeter/submillimeter Array (ALMA) potentially can find more split-personality galaxies with its improved radio "vision."

"We definitely will use ALMA to search for other objects that are similar to Centaurus A," added Espada.

These findings were published in The Astrophysical Journal Letters.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.


Story Source:

The above story is based on materials provided by Harvard-Smithsonian Center for Astrophysics. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Espada, S. Matsushita, A. B. Peck, C. Henkel, F. Israel, D. Iono. Disentangling the Circumnuclear Environs of Centaurus A: Gaseous Spiral Arms in a Giant Elliptical Galaxy. The Astrophysical Journal, 2012; 756 (1): L10 DOI: 10.1088/2041-8205/756/1/L10

Cite This Page:

Harvard-Smithsonian Center for Astrophysics. "Split-personality elliptical galaxy holds a hidden spiral." ScienceDaily. ScienceDaily, 22 October 2012. <www.sciencedaily.com/releases/2012/10/121022122237.htm>.
Harvard-Smithsonian Center for Astrophysics. (2012, October 22). Split-personality elliptical galaxy holds a hidden spiral. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2012/10/121022122237.htm
Harvard-Smithsonian Center for Astrophysics. "Split-personality elliptical galaxy holds a hidden spiral." ScienceDaily. www.sciencedaily.com/releases/2012/10/121022122237.htm (accessed July 22, 2014).

Share This




More Space & Time News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
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