MIT: Unraveling black hole spin

[bystander]

Retrograde spin of supermassive black holes may create jets that control galaxy evolution

Scattered throughout every galaxy are black holes, regions that gobble up matter and energy. Although we can’t see black holes, scientists can infer their size, location and other properties by using sensitive telescopes to detect the heat they generate. This heat, which we see as X-rays, is produced as material spirals around a black hole faster and faster until it reaches a point of no return — the “event horizon” — from which nothing, not even light, can escape.

In addition to a galaxy’s collection of black holes, which includes black holes up to 10 times the sun’s mass, there is a supermassive black hole embedded in the heart of each galaxy that is roughly one million to one billion times the mass of the sun. About 10 percent of these giant black holes feature jets of plasma, or highly ionized gas, that extend perpendicularly from each side of the event horizon. By spewing huge amounts of mostly kinetic energy, or energy created by motion, from the black holes into the universe, the jets affect how stars and other bodies form, and play a crucial role in the evolution of clusters of galaxies, the largest structures in the universe.

Color composite image of Centaurus A, revealing the lobes and jets
emanating from the active galaxy’s central black hole. (ESO/NASA)

[The Code]

This raises a question for me.

http://www.physorg.com/news185104066.html


If New forming stars, And Black Holes both have Jets. What do New forming stars have in common with black holes?

Is it the spin?

[Chris Peterson]

If New forming stars, And Black Holes both have Jets. What do New forming stars have in common with black holes?
Is it the spin?

Spin seems to be a key component. Jets (more correctly called polar jets) are probably the result of inflowing material from an accretion disc interacting with a complex rotating magnetic field, produced by the spinning central body and possibly the rotating accretion disc as well.

All jets appear to be similar in how they are formed, whether they are powerful relativistic jets from supermassive black holes, or much weaker polar jets from protostars.

[BMAONE23]

The backward spin of a number of black holes could create mysterious jets of plasma that control the fate of galaxies, scientists now suggest.
These jets control how stars and other bodies form by injecting huge amounts of energy into the universe, playing a crucial role in the evolution of clusters of galaxies, the largest structures in the universe

http://www.msnbc.msn.com/id/35370964/ns ... ce/from/ET

[bystander]

Backwards Black Holes Might Make Bigger Jets
NASA JPL 2010-186 - 01 June 2010

Going against the grain may turn out to be a powerful move for black holes. New research suggests supermassive black holes that spin backwards might produce more ferocious jets of gas. The results have broad implications for how galaxies change over time.
...
Black holes are immense distortions of space and time with gravity that is so great, even light itself cannot escape. Astronomers have known for more than a decade that all galaxies, including our own Milky Way, are anchored by tremendous, so-called supermassive black holes, containing billions of suns' worth of mass. The black holes are surrounded and nourished by disks of gas and dust, called accretion disks. Powerful jets stream out from below and above the disks like lasers, and fierce winds blow off from the disks themselves.

The black holes can spin either in the same direction as the disks, called prograde black holes, or against the flow – the retrograde black holes. For decades, astronomers thought that the faster the spin of the black hole, the more powerful the jet. But there were problems with this "spin paradigm" model. For example, some prograde black holes had been found with no jets.
...
The new study links the researchers' theory with observations of galaxies across time, or at varying distances from Earth. They looked at both "radio-loud" galaxies with jets, and "radio-quiet" ones with weak or no jets. The term "radio" comes from the fact that these particular jets shoot out beams of light mostly in the form of radio waves.

The results showed that more distant radio-loud galaxies are powered by retrograde black holes, while relatively closer radio-quiet objects have prograde black holes. According to the team, the supermassive black holes evolve over time from a retrograde to a prograde state.
...
The scientists say that the backward black holes shoot more powerful jets because there's more space between the black hole and the inner edge of the orbiting disk. This gap provides more room for the build-up of magnetic fields, which fuel the jets, an idea known as the Reynold's conjecture
...
Jets and winds play key roles in shaping the fate of galaxies. Some research shows that jets can slow and even prevent the formation of stars not just in a host galaxy itself, but also in other nearby galaxies.

The evolution of radio-loud active galactic nuclei as a function of black hole spin

• Monthly Notices of the Royal Astronomical Society, 27 May 2010, DOI: 10.1111/j.1365-2966.2010.16797.x

[astrolabe]

Hello bystander,

As an example of a plausable dynamic if the Earth's iron core were to spin in a direction opposite that of Earth's mantle and crust one would think that the Planet's magnetic field would increase by orders of magnitude. Ya think?