Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Method Developed to Weigh, Resolve Distant Black Holes

04.06.2008
Arkansas Professor presents new, simple method to learn about black holes up to eight billion light years away.

Research presented to the American Astronomical Society meeting in St. Louis today offers astronomers a new, simple method to learn about black holes up to eight billion light years away – thousands of times farther away than black holes can be measured today.

Dr. Marc Seigar, assistant professor of physics and astronomy in the College of Science and Math at the University of Arkansas at Little Rock, and his research team have concluded that the larger the black hole at the center of a spiral galaxy, the tighter the galaxy’s arms wrap around itself. If correct, the simple relationship would give researchers an easy way to learn about black holes.

“This is a really easy way to determine the masses of these super-massive black holes at the centers of galaxies that are very far away,” Seigar said. “This gives us a way to measure the size of these far away black holes.”

Since super-massive black holes were discovered in nearby galaxies, researchers have been determining their masses by looking at how fast the stars were moving in the very central regions of those galaxies. But that method only works for relatively nearby galaxies, Seigar said.

“For more distant galaxies out to the distances we’re talking about, you have to develop alternative methods,” Seigar said. “And we have developed such a method.”

The method he described to the Astronomical Society involves taking a snapshot of a distant galaxy and measuring how tightly the spiral arms wrap around the galaxy, or the wrapping angle. He determined that the more massive the black hole, the tighter the spiral arms wrap around the galaxy, which indicates a small wrapping angle.

Seigar’s team studied photographs of 27 spiral galaxies, including our galaxy, the Milky Way, and its nearest neighbor, the Andromeda Galaxy. Galaxies with the smallest black holes had spiral arms with wrapping angles of up to 43 degrees. Those with biggest black holes had spiral arms at angles of only seven degrees between their central bulges.

“One of the important reasons to learn about the every distant black holes is, when you are looking at galaxies very far away, you are looking at them as they were in the past, so you can learn about how masses of black holes grow over time, ” Seigar said.

The black holes he is studying are super-massive black holes that are millions or billions times more massive than our sun. Since they seem to be found at the centers of all galaxies, they could be a key element of how galaxies form in the first place.

His studies also indicate that the mass of a black hole may depend on how centrally concentrated the dark matter is in a galaxy. “But that is a hypothesis that has yet to be proven,” he said. “We’re going to work on that.”

Seigar joined UALR’s faculty in 2007 following a stint as an assistant project scientist and McCue Fellow at the University of California-Irvine. His other experience includes postdoctoral research associate at the University of California-Irvine, adjunct professor at the University of Hawaii-Hilo, postdoctoral research associate at the University of London’s Imperial College and at Ghent University in Belgium. He also was a visiting astronomer at the Space Telescope Science Institute.

Seigar, who earned a Ph.D. in astrophysics at John Moores University in Liverpool, teaches Introduction to Astronomy at UALR as well as performing research in the structure, dynamics and star formation in spiral galaxies, and the nature of intracluster light in clusters of galaxies.

“Since my thesis I have been interested in the overall structure, morphology and dynamics of nearby galaxies, especially disk galaxies,” Seigar said.

He is involved in the Carnegie-Irvine Nearby Galaxies Survey (CINGS), a comprehensive optical and infrared imaging survey of the 600 brightest galaxies in the southern-hemisphere sky, being carried out at the 2.5-meter Du Pont telescope at Las Campanas Observatory. He is also involved in the Arkansas Galaxy Evolution Survey (AGES), part of which is to conduct a census of super-massive black holes in the universe.

To see photographs demonstrating Seigar’s paper can be found at http://www.ualr.edu/mxseigar/pics/Andromeda.jpg and http://www.ualr.edu/mxseigar/pics/Triangulum.jpg

Joan I. Duffy | newswise
Further information:
http://www.ualr.edu

More articles from Physics and Astronomy:

nachricht APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie

nachricht First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science

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: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>