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Posts Tagged ‘supermassive black holes’

Trio Of Supermassive Black Holes Shake Space-Time


Astronomers have discovered three closely orbiting supermassive black holes in a galaxy more than 4 billion light years away. This is the tightest trio of black holes known to date and is remarkable since most galaxies have just one at their centre (usually with a mass between 1 million to 10 billion times that of the Sun). The discovery suggests that these closely packed supermassive black holes are far more common than previously thought. The team, led by South African Dr Roger Deane from the University of Cape Town, used a technique called Very Long Baseline Interferometry (VLBI) to discover the inner two black holes of the triple system. This technique combines the signals from large radio antennas separated by up to 10 000 kilometres to see detail 50 times finer than that possible with the Hubble Space Telescope. The observations were done with the European VLBI Network (EVN) and the data were correlated at the Joint Institute for VLBI in Europe (JIVE) in Dwingeloo, the Netherlands.

“What remains extraordinary to me is that these black holes, which are at the very extreme of Einstein’s Theory of General Relativity, are orbiting one another at 300 times the speed of sound on Earth”, says Deane. “Not only that, but using the combined signals from radio telescopes on four continents we are able to observe this exotic system one third of the way across the Universe. It gives me great excitement as this is just scratching the surface of a long list of discoveries that will be made possible with the Square Kilometre Array (SKA).”

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A Dance Of Black Holes


Artist’s impression of a pair of black holes.  © ESA/C. Carreau

Artist’s impression of a pair of black holes. © ESA/C. Carreau

A pair of supermassive black holes in orbit around one another have been discovered by an international research team including Stefanie Komossa from the Max Planck Institute for Radio Astronomy in Bonn, Germany. This is the first time such a pair could be found in an ordinary galaxy. They were discovered because they ripped apart a star when ESA’s space observatory XMM-Newton happened to be looking in their direction.

The findings are published in the May 10 issue of the “Astrophysical Journal”, and appeared online today at the astrophysics preprint server.

Most massive galaxies in the Universe are thought to harbour at least one supermassive black hole at their centre. Two supermassive black holes are the smoking gun that the galaxy has merged with another. Thus, finding binary supermassive black holes can tell astronomers about how galaxies evolved into their present-day shapes and sizes.

To date, only a few candidates for close binary supermassive black holes have been found. All are in active galaxies where they are constantly ripping gas clouds apart, in the prelude to crushing them out of existence.

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Active Supermassive Black Holes Revealed In Merging Galaxies

January 29, 2014 Leave a comment

Artist's rendition. Credit: NAOJ

Artist’s rendition. Credit: NAOJ

A team of astronomers has conducted infrared observations of luminous, gas-rich, merging galaxies with the Subaru Telescope to study active, mass-accreting supermassive black holes (SMBHs). They found that at least one SMBH almost always becomes active and luminous by accreting a large amount of material (Figure 1). However, only a small fraction of the observed merging galaxies show multiple, active SMBHs. These results suggest that local physical conditions near SMBHs rather than general properties of galaxies primarily determine the activation of SMBHs.

In this Universe, dark matter has a much higher mass than luminous matter, and it dominates the formation of galaxies and their large-scale structures. The widely accepted, cold-dark-matter based galaxy formation scenario posits that collisions and mergers of small gas-rich galaxies result in the formation of massive galaxies seen in the current Universe. Recent observations show that SMBHs with more than one-million solar masses ubiquitously exist in the center of galaxies. The merger of gas-rich galaxies with SMBHs in their centers not only causes active star formation but also stimulates mass accretion onto the existing SMBHs. When material accretes onto a supermassive black hole (SMBH), the accretion disk surrounding the black hole becomes very hot from the release of gravitational energy, and it becomes very luminous.

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Find Black Holes While You’re On The Bus

December 18, 2013 Leave a comment

‘Radio Galaxy Zoo’, launching today, is a new ‘citizen science’ project that lets anyone become a cosmic explorer.

By matching galaxy images with radio images from CSIRO’s Australia Telescope, you can work out if a galaxy has a supermassive black hole.

“It takes about a minute to learn what to do,” said CSIRO’s Dr Julie Banfield, an Australian coordinator of the international project. “Then to actually work with the images takes only a few seconds each — perhaps a couple of minutes for the really tough ones. You just need match up a couple of pictures and look for what you think is the galaxy at their centre.”

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Massive Black Hole Duo: Possible Sighting By NASA’s WISE

December 4, 2013 Leave a comment

Artist's conception. Image credit: NASA

Artist’s conception. Image credit: NASA

Astronomers have spotted what appear to be two supermassive black holes at the heart of a remote galaxy, circling each other like dance partners. The incredibly rare sighting was made with the help of NASA’s Wide-field Infrared Survey Explorer, or WISE.

Follow-up observations with the Australian Telescope Compact Array near Narrabri, Australia, and the Gemini South telescope in Chile, revealed unusual features in the galaxy, including a lumpy jet thought to be the result of one black hole causing the jet of the other to sway.

“We think the jet of one black hole is being wiggled by the other, like a dance with ribbons,” said Chao-Wei Tsai of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., who is lead author of a paper on the findings appearing in the Dec. 10 issue of Astrophysical Journal. “If so, it is likely the two black holes are fairly close and gravitationally entwined.”

The findings could teach astronomers more about how supermassive black holes grow by merging with each other.

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Unique Chemical Composition Surrounding Supermassive Black Hole – A Step Toward Development Of New Black Hole Exploration Method

October 24, 2013 Leave a comment

The Atacama Large Millimeter/submillimeter Array (ALMA) successfully captured a detailed image of high density molecular gas around an active galactic nucleus harboring a supermassive black hole. The observations at the highest ever achieved reveal a unique chemical composition characterized by enhancement of hydrogen cyanide (HCN) around the black hole. An research team thought a high temperature affected by the black hole caused this peculiar chemical properties. The team expect that this unique chemical properties can be used to find black holes hidden behind dust.

The research findings are presented in the article “Submillimeter ALMA Observation of the Dense Gas in the Low-Luminosity Type-1 Active Nucleus of NGC 1097” published in the Publication of the Astronomical Society of Japan, Vol. 65, of October 25, 2013.

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Fat Black Holes Grown Up In Cities: “Observational” Result Using Virtual Observatory

October 18, 2013 Leave a comment

A research team, led by reseacher at the National Astronomical Observatory of Japan (NAOJ), discovered that the more massive black holes tend to be located in galactic environments with higher density . This finding indicates that galaxies in a dense area often merge together, causing the growth of massive black holes.

The research team investigated environment in which a galaxy with a massive black hole at its center exists. The team’s research extended over data for approximately 70 million galaxies, with approximately 10,000 massive black holes researched. This vast amount of data was collected through the Virtual Observatory; it connects a variety of astronomical databases around the world via the Internet, making it possible to comprehensively use the collected data.

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