Featured Research

from universities, journals, and other organizations

Astronomers Detect Black Hole In Tiny 'Dwarf' Galaxy

Date:
January 8, 2007
Source:
University of Washington
Summary:
Astronomers have found evidence of a supermassive black hole at the heart of a dwarf elliptical galaxy about 54 million light years away from the Milky Way galaxy where Earth resides.

A Hubble Space Telescope image shows a dwarf galaxy, VCC128, at the center, and the enlargement at right shows a double nucleus that suggests the presence of a black hole.
Credit: NASA/Hubble Space Telescope

Astronomers have found evidence of a supermassive black hole at the heart of a dwarf elliptical galaxy about 54 million light years away from the Milky Way galaxy where Earth resides.

It is only the second time a supermassive black hole has been discerned in a dwarf galaxy, and only the third time that astronomers have observed a double nucleus at the heart of a galaxy, said Victor P. Debattista, a postdoctoral researcher in astronomy at the University of Washington.

The galaxy, called VCC128, lies in the Virgo Cluster and is about 1 percent the size of the Milky Way. All of its stars combined would equal 100 million to 1 billion of our suns, Debattista said.

"It's a very small galaxy, on the outskirts of the cluster," he said. "It is effectively the smallest galaxy in which there is a supermassive black hole."

Black holes lie at the center of many galaxies, and have gravitational fields so powerful that nothing -- not even light -- can escape. A supermassive black hole is so large that its mass equals anywhere between 100,000 and 10 billion of our suns.

Debattista is the lead author of a poster detailing the discovery being presented today at the American Astronomical Society national meeting in Seattle. Co-authors are Ignacio Ferreras of Kings College in London, Anna Pasquali of the Max-Planck-Institut fόr Astronomie in Germany, Anil Seth at the Harvard-Smithsonian Center for Astrophysics in Boston, Sven De Rijcke of the Universiteit Gent in Belgium, and Lorenzo Morelli of Pontificia Universidad Catσlica in Chile. The work was funded by a grant from the National Science Foundation, a Brooks Prize Fellowship at the UW and the Fund for Scientific Research in Belgium.

The scientists were sifting through archived data from the Hubble Space Telescope when they found the supermassive black hole. They were studying the nuclei of dwarf galaxies, which are thought to develop from globular clusters, tightly packed spherical collections of stars that orbit a galaxy. As they examined the properties of the nuclei, they discovered one galaxy, VCC128, that had a double nucleus. Ultimately they determined the double nucleus is made up of two points of light from stars collected at opposite edges of a ring surrounding a black hole. Using the 3.5-meter telescope at the Apache Point Observatory in New Mexico, they measured properties of light from the nucleus and found that the nucleus is a ring of stars at least 1 billion years old, meaning the system probably is very stable.

"The fact that we found a black hole is impressive because it's been thought that a galaxy this small should not be able to host a black hole," Debattista said. "It had been speculated that dwarf galaxies like this could not make black holes."

The researchers believe the black hole has a mass at least equal to the ring of stars surrounding it, ranging from 1 million to 50 million times the mass of our sun.

"The question remains whether other dwarf galaxies with bright nuclei are indeed similar systems. We may not see more of these stellar rings because they are so small," said Ferreras.

The finding helps in understanding the processes occurring in low-mass dwarf galaxies as they travel through space and merge with other dwarfs to form larger galaxies. As that happens, their black holes also become more massive.

"The dwarf galaxies that escaped from this merging process offer us the opportunity to study the properties of the building blocks of today's massive galaxies and the supermassive black holes they host," said De Rijcke.


Story Source:

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


Cite This Page:

University of Washington. "Astronomers Detect Black Hole In Tiny 'Dwarf' Galaxy." ScienceDaily. ScienceDaily, 8 January 2007. <www.sciencedaily.com/releases/2007/01/070107210144.htm>.
University of Washington. (2007, January 8). Astronomers Detect Black Hole In Tiny 'Dwarf' Galaxy. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2007/01/070107210144.htm
University of Washington. "Astronomers Detect Black Hole In Tiny 'Dwarf' Galaxy." ScienceDaily. www.sciencedaily.com/releases/2007/01/070107210144.htm (accessed October 20, 2014).

Share This



More Space & Time News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) — Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) — Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) — The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com
Comet Set for Rare Close Shave With Mars

Comet Set for Rare Close Shave With Mars

AFP (Oct. 16, 2014) — A fast-moving comet is about to shave by Mars for a once-in-a-million-years encounter that a flurry of spacecraft around the Red Planet hope to capture and photograph, NASA said. Video provided by AFP
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