Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers pierce galactic clouds to shine light on black hole development

20.06.2014

International team helps explain how black hole outflows affect structure formation in universe

An international team of scientists including a Virginia Tech physicist have discovered that winds blowing from a supermassive black hole in a nearby galaxy work to obscure observations and x-rays.


This is an illustration of the physical, spatial and temporal picture for the outflows emanating from the vicinity of the super massive black hole in the galaxy NGC 5548. The behavior of the emission source in five epochs is shown along the time axis. The obscurer is situated at roughly 0.03 light years (0.01 parsecs) from the emission source and is only seen in 2011 and 2013 (it is much stronger in 2013). Outflow component 1 shows the most dramatic changes in its absorption troughs. Different observed ionic species are represented as colored zones within the absorbers.

Credit: Ann Feild/Space Telescope Science Institute

The discovery in today's (June 19, 2004) issue of Science Express sheds light on the unexpected behavior of black holes, which emit large amounts of matter through powerful, galactic winds.

Using a large array of satellites and space observatories, the team spent more than a year training their instruments on the brightest and most studied of the "local" black holes — the one situated at the core of Type I Seyfert Galaxy NGC 5548.

What they found was a bit of a surprise.

The researchers discovered much colder gas than expected based on past observations, showing that the wind had cooled and that a stream of gas moved quickly outward and blocked 90 percent of x-rays. The observation was the first direct evidence of an obscuration process that — in more luminous galaxies — has been shown to regulate growth of black holes.

By looking at data from different sources, scientists found that a thick layer of gas lay between the galactic nucleus and the Earth blocked the lower energy x-rays often used to study the system, but allowed more energetic x-rays to get through.

Data from Hubble Space Telescope also showed ultraviolet emissions being partially absorbed by a stream of gas.

A multi-wavelength observational campaign simultaneously looking at an object to decipher its secrets is rare, the researchers said.

"I don't think anyone has trained so many scopes and put in so much time on a single object like this," said Nahum Arav, an associate professor of physics with Virginia Tech's College of Science. "The result is quite spectacular. We saw something that was never studied well before and we also deciphered the outflow in the object. We know far more about this outflow than any studied previously as to where it is and how it behaves in time. We have a physical model that explains all the data we've taken of the outflow over 16 years."

The discovery was made by an international team led by SRON Netherlands Institute for Space Research scientist Jelle Kaastra using the major space observatories of the European Space Agency, NASA, the Hubble Space Telescope, Swift, NuSTAR, Chandra, INTREGRAL, and other satellites and observation platforms.

"These outflows are thought to be a major player in the structure formation of the universe," Arav said "This particular outflow is comparatively small but because it's so close we can study it very well and then create a better understanding of how the phenomenon will work in very large objects that do affect the structure formation in the universe."

"Shadowing" of light from a black hole had not been seen before. With the discovery, scientists were able to decipher the outflow.

"Until now our knowledge of these characteristics was very limited," Arav said. "Before we were making educated inferences — but now we know. We know the distance of outflow from the center of source, we know the mass of outflow, and we know what causes its observed changes. The shadowing was definitely a surprise —a beautiful phenomenon we were lucky to catch."

Arav said luck played a part because the effect hadn't existed before last year.

Over the past two years the shadowing has built up and Arav believes it won't last much longer than another year or two, but concedes scientists don't have a full enough observation to say how the shadowing feature is changing in time.

Rosaire Bushey | Eurek Alert!
Further information:
http://www.vt.edu

Further reports about: Astronomers Hubble Space Telescope clouds observations phenomenon satellites shine structure winds

More articles from Physics and Astronomy:

nachricht Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>