|
How to Make A Black Hole Choke
November 16, 1999Embargoed until 22 November 1999
Black holes, by swallowing material from their surroundings, provide the power for some of the most energetic and luminous objects in the Universe.
It has long been believed that a black hole can swallow everything that is fed into it. But research by a team at the Institute of Astronomy, at the University of Cambridge, has shown that this is not so.
If you try to feed a black hole with matter too fast, it will "choke" and only manage to swallow a small amount.
The discovery was made by Professor Jim Stone, Dr Jim Pringle and Professor Mitch Begelman, at the University's Institute of Astronomy, who carried out computer-simulated experiments to analyse how black holes swallow material.
"The reason black holes seem to shine so brightly is that the material they swallow is initially in orbit about them," explained Dr Pringle.
"To let material fall in to a black hole we need to slow that material down. As it slows down, the energy released makes the material glow, and it is this hot material falling into the black hole that we see, not the black hole itself.
"But an important question is whether or not all the material which falls into the black hole can be seen."
The team looked at existing research which assumes that black holes have grown mainly by swallowing material.
As they did this, they should have been radiating a lot of energy. By looking out to large distances - and thus back in time - astronomers should be able to see this happening.
But so far, no evidence has been found of this huge release of energy and the team at the Institute of Astronomy have been trying to find out why.
Professor Stone said: "The idea that black holes can swallow material surreptitiously which does not glow has been growing in popularity.
"If black holes can really eat without being seen, it should be possible to force-feed them until they grow to the required size."
The team began their research with a computer simulation with a ring of material in orbit around a central black hole. They then let the material go, assuming that, although it would get hot as it slowed down, it would be unable to glow.
Prof Stone said: "Sure enough, the material did slow down and start to fall towards the hole and it did heat up as it did so.
"According to previous ideas, the hole should have swallowed the material without any problems. But instead, as the material fell inwards, more and more of it was turned back out again and only a small fraction of the material actually reached the black hole.
"The conclusion we have to draw from this is that, if you try to force-feed a black hole, it will choke."
For further information, please contact:
1. Dr Jim Pringle, Institute of Astronomy, University of Cambridge. Tel: 01223 337513; enquiries: 01223 337548; e-mail: jep@ast.cam.ac.uk
2. Dr Gerry Gilmore, Deputy Director, Institute of Astronomy, University of Cambridge. Tel: 01223 337506; e-mail: gil@ast.cam.ac.uk
3. Beck Lockwood, Press and Publications Office, University of Cambridge.
Tel: 01223 332300; e-mail: rll24@cam.ac.uk
Cambridge, University of
1. Dr Jim Pringle, Institute of Astronomy, University of Cambridge. Tel: 01223 337513; enquiries: 01223 337548; e-mail: jep@ast.cam.ac.uk
2. Dr Gerry Gilmore, Deputy Director, Institute of Astronomy, University of Cambridge. Tel: 01223 337506; e-mail: gil@ast.cam.ac.uk
3. Beck Lockwood, Press and Publications Office, University of Cambridge.
Tel: 01223 332300; e-mail: rll24@cam.ac.uk
Cambridge, University of
Black Hole News and Current Black Hole Events RSSA new method to weigh giant black holes
How do you weigh the biggest black holes in the universe? One answer now comes from a new and independent technique that UC Irvine scientists and other astronomers have developed using data from NASA's Chandra X-ray Observatory.
UCSB professor's paper on safety of large hadron collider to be published in Physical Review D
Particle colliders creating black holes that could devour the Earth. Sounds like a great Hollywood script.
Radio Telescopes Reveal Unseen Galactic Cannibalism
Radio-telescope images have revealed previously-unseen galactic cannibalism -- a triggering event that leads to feeding frenzies by gigantic black holes at the cores of galaxies. Astronomers have long suspected that the extra-bright cores of spiral galaxies called Seyfert galaxies are powered by supermassive black holes consuming material. However, they could not see how the material is started on its journey toward the black hole.
Black holes have simple feeding habits
The biggest black holes may feed just like the smallest ones, according to data from NASA's Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes.
UC Santa Cruz physicists eagerly await launch of NASA space telescope they helped build
When NASA launches its newest space observatory, physicists at the University of California, Santa Cruz, will be watching as the product of nearly 16 years of hard work blasts into orbit.
Supernova birth seen for first time
Astronomers have seen the aftermath of spectacular stellar explosions known as supernovae before, but until now no one has witnessed a star dying in real time.
Discovery of most recent supernova in our galaxy
The most recent supernova in our Galaxy has been discovered by tracking the rapid expansion of its remains. This result, using NASA's Chandra X-ray Observatory and NRAO's Very Large Array (VLA), has implications for understanding how often supernovas explode in the Milky Way galaxy.
Catching a Glimpse of a Black Hole's Fury
Using the National Science Foundation's (NSF) Very Long Baseline Array (VLBA) and a host of international telescope partners, a team of researchers has made the clearest observation yet of innermost region of a black hole.
Milky Way's Giant Black Hole Awoke from Slumber 300 Years Ago
Using NASA, Japanese, and European X-ray satellites, a team of Japanese astronomers has discovered that our galaxy's central black hole let loose a powerful flare three centuries ago.
RIT Team Simulates First Merger of Three Black Holes on a Supercomputer
The same team of astrophysicists that cracked the computer code simulating two black holes crashing and merging together has now, for the first time, caused a three-black-hole collision.
More Black Hole News Articles
 | The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics by Leonard Susskind |
 | Black Hole by Charles Burns |
 | Death by Black Hole: And Other Cosmic Quandaries by Neil deGrasse Tyson |
 | Radical Amazement: Contemplative Lessons from Black Holes, Supernovas, And Other Wonders of the Universe by Judy Cannato |
 | An Introduction To Black Holes, Information And The String Theory Revolution: The Holographic Universe by Leonard Susskind, James Lindesay |
 | Black Holes and Time Warps: Einstein's Outrageous Legacy (Commonwealth Fund Book Program) by Kip S. Thorne |
 | Everyone Worth Knowing by Lauren Weisberger |
 | As She Climbed Across the Table: A Novel by Jonathan Lethem |
 | A Brief History of Time: From the Big Bang to Black Holes by Stephen Hawking |
 | Cosmic Catastrophes: Exploding Stars, Black Holes, and Mapping the Universe by J. Craig Wheeler |
| © 2008 BrightSurf.com |