Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers detect black hole in tiny 'dwarf' galaxy

09.01.2007
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 für 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 Católica 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.

Vince Stricherz | EurekAlert!
Further information:
http://www.washington.edu

More articles from Physics and Astronomy:

nachricht Extremely fine measurements of motion in orbiting supermassive black holes
28.06.2017 | Stanford University

nachricht Ultra-compact phase modulators based on graphene plasmons
27.06.2017 | ICFO-The Institute of Photonic Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Predicting eruptions using satellites and math

28.06.2017 | Earth Sciences

Extremely fine measurements of motion in orbiting supermassive black holes

28.06.2017 | Physics and Astronomy

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>