Featured Research

from universities, journals, and other organizations

Three-telescope interferometry allows astrophysicists to observe how black holes are fueled

Date:
May 16, 2012
Source:
University of California - Santa Barbara
Summary:
By combining the light of three powerful infrared telescopes, scientists have observed the active accretion phase of a supermassive black hole in the center of a galaxy tens of millions of light years away, a method that has yielded an unprecedented amount of data for such observations. The resolution at which they were able to observe this highly luminescent active galactic nucleus has given them direct confirmation of how mass accretes onto black holes in centers of galaxies.

This is an artist's view of a dust torus surrounding the accretion disk and the central black hole in active galactic nuclei.
Credit: NASA E/PO - Sonoma State University, Aurore Simonnet

By combining the light of three powerful infrared telescopes, an international research team has observed the active accretion phase of a supermassive black hole in the center of a galaxy tens of millions of light years away, a method that has yielded an unprecedented amount of data for such observations. The resolution at which they were able to observe this highly luminescent active galactic nucleus (AGN) has given them direct confirmation of how mass accretes onto black holes in centers of galaxies.

"This three-telescope interferometry is a major milestone toward directly imaging the growth phase of supermassive black holes," said Sebastian Hoenig, a postdoctoral researcher at the UC Santa Barbara Department of Physics, and one of the astrophysicists who utilized this technique to observe the AGN at the center of galaxy NGC 3783. The observation was led by Gerd Weigelt, a director of the Max Planck Institute for Radio Astronomy in Bonn, Germany.

Hoenig described their findings as a ring of hot dust that marks the transition from a more-distant mixture of gas and dust in a toroidal (doughnut-shaped) structure, to a gaseous disk closer to the black hole. The dusty part, he said, is interesting because it dominates the infrared emission of active galactic nuclei and can be easily observed.

However, observing the ring of hot dust in NGC 3783 was a challenge for the astrophysicists. Not only is the ring distant and faint, but the ability of individual infrared telescopes to resolve distances between actively accreting objects is also highly limited. Even the largest optical/infrared telescopes in the world, the Keck telescopes, were not powerful enough, though they can show objects in the infrared comparable to about the size of a football field at the distance of the moon.

"In order to spatially resolve the accretion process onto supermassive black holes in nearby galaxies, we have to be at least a factor of ten better," said Hoenig. To achieve that angular resolution in a single telescope, it would have to be 130 meters in diameter.

However, by using the AMBER interferometry instrument to simultaneously combine the light from three 8-meter telescopes at the Very Large Telescope Interferometer (VLTI) at the Paranal Observatory in Chile, the research team was able to achieve the angular resolution needed to observe the hot dust ring. The Paranal Observatory is operated by the European Southern Observatories (ESO).

The combination of the light from the three telescopes was no small feat, as the tiny differences in the arrival of light in the individual telescopes have to undergo constant correction with an accuracy of a few micrometers -- roughly ten times smaller than the thickness of a hair, according to Hoenig.

"The ESO VLTI provides us with a unique opportunity to improve our understanding of active galactic nuclei," said lead researcher Weigelt. "It allows us to study fascinating physical processes with unprecedented resolution over a wide range of infrared wavelengths. This is needed to derive physical properties of these sources."

Up next for the research team, which also includes astrophysicists from the universities of Florence, Grenoble, and Nice, will be the continued accumulation of information from additional observations toward a highly detailed image of the active galactic nucleus at galaxy NGC 3783.

"Our main interest is to learn how supermassive black holes in the centers of galaxies are fueled, so that they grow to the enormous million to billion solar mass objects we see today," said Hoenig.


Story Source:

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


Cite This Page:

University of California - Santa Barbara. "Three-telescope interferometry allows astrophysicists to observe how black holes are fueled." ScienceDaily. ScienceDaily, 16 May 2012. <www.sciencedaily.com/releases/2012/05/120516140101.htm>.
University of California - Santa Barbara. (2012, May 16). Three-telescope interferometry allows astrophysicists to observe how black holes are fueled. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2012/05/120516140101.htm
University of California - Santa Barbara. "Three-telescope interferometry allows astrophysicists to observe how black holes are fueled." ScienceDaily. www.sciencedaily.com/releases/2012/05/120516140101.htm (accessed April 21, 2014).

Share This



More Space & Time News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

SpaceX's Dragon Spacecraft Captured by International Space Station

SpaceX's Dragon Spacecraft Captured by International Space Station

Reuters - US Online Video (Apr. 20, 2014) — SpaceX's unmanned Dragon spacecraft makes a scheduled Easter Sunday rendezvous with the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Raw: Easter Morning Delivery for Space Station

Raw: Easter Morning Delivery for Space Station

AP (Apr. 20, 2014) — Space station astronauts got a special Easter treat: a cargo ship full of supplies. The SpaceX company's cargo ship, Dragon, spent two days chasing the International Space Station following its launch from Cape Canaveral. (April 20) Video provided by AP
Powered by NewsLook.com
Extremely Large Telescope Could Spot Alien Life

Extremely Large Telescope Could Spot Alien Life

Newsy (Apr. 20, 2014) — Scientists are preparing to blow up a Chilean mountain to construct the Extremely Large Telescope, which will take detailed pictures of exoplanets. Video provided by Newsy
Powered by NewsLook.com
A Hoax? Cosmetics Company Wants To Brighten The Moon

A Hoax? Cosmetics Company Wants To Brighten The Moon

Newsy (Apr. 19, 2014) — FOREO, a Swedish cosmetics company, says it wants to brighten the moon to lower electricity costs. Video provided by Newsy
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