View Full Version : Doughnut Around a Giant Black Hole

2005-Sep-30, 07:14 AM
SUMMARY: Astronomers now believe that a supermassive black hole lies at the heart of most galaxies. In some cases, the area around the black hole is so bright it outshines the rest of the galaxy by several orders of magnitude. Indirect evidence tells astronomers that a thick doughnut-shaped structure of gas and dust (called a torus) enshrouds the black holes, but one had never been seen directly, until now. Using the European Southern Observatory's VTL Interferometer, which combines the light from several telescopes, astronomers have been able to resolve the structures at the heart of galaxy NGC 1068.

View full article (http://www.universetoday.com/am/publish/doughnut_around_black_hole.html)
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2005-Sep-30, 08:05 AM
this is an old article too.

2005-Sep-30, 01:29 PM
From the linked article:

The MIDI instrument on the VLTI is thus the most appropriate instrument to peer at the enigmatic dust and gas tori believed to be located around giant black holes at the centres of quasars and Active Galactic Nuclei.

And since nobody has ever been able to use interferometry to study faint objects in the thermal infrared, MIDI enters into a whole unexplored territory.

On the nights of June 14 to 16, a team of European astronomers [2] conducted a first series of observations to verify the scientific potential of MIDI on the VLTI. Among them, they studied the active galaxy NGC 1068.
NGC 1068 is among the brightest and most nearby active galaxies. Located in the constellation Cetus at a distance of about 60 million light years, it is also known as Messier 77. It is in fact one of the biggest galaxies in Messier's catalogue and one of the first recognised spiral galaxies. On optical images, NGC 1068 looks indeed like a rather normal barred spiral galaxy. The core of the galaxy, however, is very luminous not only in the optical, but also in ultraviolet and X-ray light. A black hole with a mass equivalent to approximately 100 million stars like our Sun is required to account for the nuclear activity in NGC 1068. Objects of this mass and density must exhibit an easily measurable Lens-Thirring effect. Are there plans to investigate whether there is such an effect and to quantify it?

Does this mean that previous estimates of quasar energy production has been greatly exaggerated because omni-directionality of quasar radiation was assumed when what we are actually seeing is a highly collimated beam?

Can there be a transfer of (gravitational potential) energy from the black hole to the kinetic energy associated with the radiation from the black hole as well as the space dragging modifications to the Higgs field?