Black hole jets

Jan 16, 2012
Jets emitted from the accretion disk around a black hole that has an orbiting companion star (an artist's conception). New research is consistent with the idea that the spin of the black hole powers the jets via magnetic fields in the disk

(PhysOrg.com) -- Black holes are irresistible sinks for matter and energy. They are so dense that not even light can escape from their gravitational clutches. Massive black holes (equal to millions or even billions of solar masses) develop during collisions between galaxies. More ordinary, stellar-mass-sized black holes form as remnants of the explosive deaths of stars, and are thought to contain not more than about twenty solar masses of material.

Astronomers study not only because they are bizarre. They are also fundamental to our understanding of gravity and to the evolutionary cycle of . Observational research is possible because, despite their reputation for being pitiless devourers of matter and energy, black holes are often sources of powerful radiation, for the following reason. When the black hole has a orbiting it, matter from the companion can form a disk of material close to the black hole. These disks often radiate brightly from the heat of friction. Moreover, of material from the companion star, if they fall onto the disk, can result in the occasional ejection of powerful jets of charged particles, sometimes at speeds approaching that of light.

What actually powers these jets has been a mystery. Astronomers and physicists have known that a black hole that spins could in principle produce a jet, but a mechanism for doing so has been a puzzle. Some scientists have suggested that magnetic fields in the vicinity of an accreting, rotating black hole could become twisted, enabling them to carry away energy as an electromagnetic jet, but there has been no direct observational evidence for such a link. Until now.

CfA astronomers Ramesh Narayan and Jeffrey McClintock have been able to estimate the spin of a black hole using models for the X-rays that are emitted. They made such estimates for four black hole binaries. Then they examined the strength of the radio continuum emission from these objects, emission that is a measure of the jet activity. The four objects span a wide range of spins and jet powers. They find for the first time convincing, direct evidence that the jet power scales with the black hole spin, consistent with (though not proof of) the idea that the jets are driven directly by the spin energy of an accreting black hole.

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joefarah
5 / 5 (1) Jan 16, 2012
Here is how the jets occur. The fast spin of the black hole create magnetic and electromagnetic fields that cause magnetic/charged matter to experience vast forces, especially when the charged volume of the spinning black hole is significant. The poles of this magnetism. are the poles of the spin, and these forces are sufficient in size to counteract the force of gravity. Hence, the matter does not have to move rapidly (i.e. near or > c) from the center of the black hole, but does continually move outward at a sufficiently rapid pace that is sufficient to counteract gravity. Yes it is true that light, per se, cannot escape a black hole, but matter, which has other forces acting on it besides gravity, can have a net positive acceleration (i.e. away from the black hole) without having to move faster than c. It simply moves at high speed (e.g. .05c) away from the center of the black hole due to the magnetic forces acting on it.
rawa1
1 / 5 (5) Jan 16, 2012
Black holes are irresistible sinks for matter and energy
IMO the photons of energy lower than the energy of CMBR may escape from black hole in the same way, like the neutrinos of energy higher than the CMBR photons. The another opportunity for matter are black hole jets, which represent the holes in the even horizon of black holes, transparent for short wavelength photons and leptons. If we would live inside of black hole, it would behave like mirror, reflecting the light from inside (with substantial red shift indeed). And the jets would behave like the dark spots in this mirror.

IMO there is some connection to the mirror hall model of universe, as presented here. http://physicswor...nt/23009 The observable universe appears like interior of dark matter foam, the membranes of which are reflecting subtle portion of light back again.

rawa1
1.1 / 5 (7) Jan 16, 2012
IMO this hypothesis is testable and the images of "first stars" are actually a reflections of nearby stars from the dark matter walls, filling the cosmic space. They're red-shifted and expanded, but they correspond the much closer objects at the another place of the sky.

http://www.nasa.g..._300.jpg
rawa1
1 / 5 (6) Jan 16, 2012
it is true that light, per se, cannot escape a black hole, but matter, which has other forces acting on it besides gravity
The jets may be formed with stream of neutrinos, which condense into heavier particles outside of black hole. Because neutrinos are wave packets stuffed with gravitational waves, they tend to move like the tachyons and they can escape from event horizon of black holes in the same way, like the infrared photons.
SteveL
3 / 5 (2) Jan 16, 2012
The another opportunity for matter are black hole jets, which represent the holes in the even horizon of black holes
You mean holes in the accretion disk, not the event horizon, correct? Because if you actually meant the event horizon, well, that would be impossible and contrary to the definition.
LKD
1 / 5 (1) Jan 19, 2012
SteveL,

Didn't Hawking propose Hawking radiation; that black holes are subject to losing matter/energy from within the event horizon?

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