NASA say they've caught some of the best ever pictures of a blackhole in space and its effect on the stars around it.
Dramatic images showing the effects of a massive black hole on a nearby galaxy have been released by Nasa.
The space agency say the images are the best to date and show opposing jets of high energy particles extending to the outer reaches of space.
The pictures were taken by the Chandra-X-ray Observatory over a week of continuous observation.
Astronomers believe the pictures also show a rare type of star system, with multiple black holes in it.
Experts say in this extremely rare case, two stars are formed at exactly the same time, one larger than the other, which eventually collapses to form a black hole and then slowly devours the other star.
To find one is amazing, but these pictures show two in Centaurus A alone, implying scientists do not understand the inner workings of the systems as intimately as they had first thought. Chandra has been operating in space since 1999 and takes pictures of activity billions of light years away.
Even Thin Galaxies Can Grow Fat Black Holes
« Reply #1 on: 2008-01-10 16:55:08 »
NASA's Spitzer Space Telescope has detected plump black holes where least expected -- skinny galaxies.
Source:Physorg.com Date: 01/10/08 Author(s): Not credited Credit: NASA
This artist's concept illustrates the two types of spiral galaxies that populate our universe: those with plump middles, or central bulges (upper left), and those lacking the bulge (foreground). Credit: NASA
Like people, galaxies come in different shapes and sizes. There are thin spirals both with and without central bulges of stars, and more rotund ellipticals that are themselves like giant bulges. Scientists have long held that all galaxies except the slender, bulgeless spirals harbor supermassive black holes at their cores. Furthermore, bulges were thought to be required for black holes to grow.
The new Spitzer observations throw this theory into question. The infrared telescope surveyed 32 flat and bulgeless galaxies and detected monstrous black holes lurking in the bellies of seven of them. The results imply that galaxy bulges are not necessary for black hole growth; instead, a mysterious invisible substance in galaxies called dark matter could play a role.
"This finding challenges the current paradigm. The fact that galaxies without bulges have black holes means that the bulges cannot be the determining factor, " said Shobita Satyapal of the George Mason University, Fairfax, Va. "It's possible that the dark matter that fills the halos around galaxies plays an important role in the early development of supermassive black holes."
Satyapal presented the findings today at the 211th meeting of the American Astronomical Society in Austin, Texas. A study from Satyapal and her team will be published in the April 10 issue of the Astrophysical Journal.
Our own Milky Way is an example of a spiral galaxy with a bulge; from the side, it would look like a plane seen head-on, with its wings out to the side. Its black hole, though dormant and not actively "feeding," is several million times the mass of our sun.
Previous observations had suggested that bulges and black holes flourished together like symbiotic species. For instance, supermassive black holes are almost always about 0.2 percent the mass of their galaxies' bulges. In other words, the more massive the bulge, the more massive the black hole. Said Satyapal, "Scientists reasoned that somehow the formation and growth of galaxy bulges and their central black holes are intimately connected."
But a wrinkle appeared in this theory in 2003, when astronomers at the University of California, Berkeley, and Observatories of the Carnegie Institution of Washington, Pasadena, Calif., discovered a relatively "lightweight" supermassive black hole in a galaxy lacking a bulge. Then, earlier this year, Satyapal and her team uncovered a second supermassive black hole in a similarly svelte galaxy.
In the latest study, Satyapal and her colleagues report the discovery of six more hefty black holes in thin galaxies with minimal bulges, further weakening the "bulge-black hole" theory. Why hadn't anybody seen these black holes before? According to the scientists, bulgeless galaxies tend to be very dusty, letting little visible light escape. But infrared light can penetrate dust, so the team was able to use Spitzer's infrared spectrograph to reveal the "fingerprints" of active black holes lurking in galaxies millions of light years away.
"A feeding black hole spits out high-energy light that ionizes much of the gas in the core of the galaxy," said Satyapal. "In this case, Spitzer identified the unique fingerprint of highly ionized neon -- only a feeding black hole has the energy needed to excite neon to this state." The precise masses of the newfound black holes are unknown.
If bulges aren't necessary ingredients for baking up supermassive black holes, then perhaps dark matter is. Dark matter is the enigmatic substance that permeates galaxies and their surrounding halos, accounting for up to 90 percent of a galaxy's mass. So-called normal matter makes up stars, planets, living creatures and everything we see around us, whereas dark matter can't be seen. Only its gravitational effects can be felt. According to Satyapal, dark matter might somehow determine the mass of a black hole early on in the development of a galaxy.
"Maybe the bulge was just serving as a proxy for the dark matter mass -- the real determining factor behind the existence and mass of a black hole in a galaxy's center," said Satyapal.
Other authors of this study include: D. Vega of the George Mason University; R.P. Dudik of the George Mason University and NASA Goddard Space Flight Center, Greenbelt, Md.; N.P. Abel of the University of Cincinnati, Ohio; and Tim Heckman of the Johns Hopkins University, Baltimore, Md.
A new study using results from NASA's Chandra X-ray Observatory provides one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly. The whirling of these giant black holes drives powerful jets that pump huge amounts of energy into their environment and affects galaxy growth.
Results from NASA's Chandra X-ray Observatory, combined with new theoretical calculations, provide one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly. The images on the left show 4 out of the 9 large galaxies included in the Chandra study, each containing a supermassive black hole in its center.
A team of scientists compared leading theories of jets produced by rotating supermassive black holes with Chandra data. A sampling of nine giant galaxies that exhibit large disturbances in their gaseous atmospheres showed that the central black holes in these galaxies must be spinning at near their maximum rates.
"We think these monster black holes are spinning close to the limit set by Einstein’s theory of relativity, which means that they can drag material around them at close to the speed of light," said Rodrigo Nemmen, a visiting graduate student at Penn State University, and lead author of a paper on the new results presented at American Astronomical Society in Austin, Texas.
The research reinforces other, less direct methods previously used which have indicated that some stellar and supermassive black holes are spinning rapidly.
According to Einstein’s theory, a rapidly spinning black hole makes space itself rotate. This effect, coupled with gas spiraling toward the black hole, can produce a rotating, tightly wound vertical tower of magnetic field that flings a large fraction of the inflowing gas away from the vicinity of the black hole in an energetic, high-speed jet. Computer simulations by other authors have suggested that black holes may acquire their rapid spins when galaxies merge, and through the accretion of gas from their surroundings.
"Extremely fast spin might be very common for large black holes," said co-investigator Richard Bower of Durham University. "This might help us explain the source of these incredible jets that we see stretching for enormous distances across space."
One significant connection consequence of powerful, black-hole jets in galaxies in the centers of galaxy clusters is that they can pump enormous amounts of energy into their environments, and heat the gas around them. This heating prevents the gas from cooling, and affects the rate at which new stars form, thereby limiting the size of the central galaxy. Understanding the details of this fundamental feedback loop between supermassive black holes and the formation of the most massive galaxies remains an important goal in astrophysics.
Re:Black Hole Blow Out! New Evidence Emerges.
« Reply #3 on: 2008-01-11 00:52:49 »
[Blunderov] I started wondering about what would cause a black hole to spin. Why would it bother? All forces are emphasised and oriented towards the centre of the hole. Where would spin-energy come from? How would it maintain that distinct character in the face of all the massive inwardly directed energy?
At least I get one thing now; the dimension of spin. Everything spins. All the "time".
"It ain't no use to sit and wonder why, babe It don't matter, anyhow An' it ain't no use to sit and wonder why, babe If you don't know by now" ~ Dylan
Re:Black Hole Blow Out! New Evidence Emerges.
« Reply #4 on: 2008-01-11 19:54:18 »
If entering particles have spin (in the classic rather than the quantum meaning) then that spin must be conserved within the system unless it can be transformed (e.g. generation of power) or transferred (in the form of torque). As initial examination of black holes disclosed no mechanisms for the release of energy from within the Schwartzchild radius (although Hawking Radiation is hypothesized to do this), we therefore surmised that the angular momentum has to be preserved. Study of pulsating radiofrequency sources, primarily quasars, has supported this theoretical conclusion with a wide array of observational confirmation most notably rapid variations in signals proving rapid rotation of the source which must be the accretion disk located outside black holes.
We can safely conclude that the principle of the conservation of angular momentum applies within Black holes.
Torque in the form of gravity drag related to the accretion zone is applied to surrounding objects and is then returned to the accretion zone, amplified by the spin and kinetic energy of captured objects. As the moment of inertia of a black hole is vast, any acquired spin in the accretion zone is not easy to dispose of. In addition, even if incoming particles do not have spin (unlikely) before entering the capture zone, they will be accelerated from the accretion disk as they spiral in towards the Schwartzchild radius (think of the coin collection funnels one sometimes see at supermarkets and even the vortex as water enters a low pressure area) and the amount of spin transferred to the black hole in this process will be substantial.
With or without religion, you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion. - Steven Weinberg, 1999
which has some helpful diagrams and an interesting, if esoteric, discussion of the care and feeding of black holes.
<snip> Originally Posted by jmercer How is it possible for a rotating black hole to have two horizons???
The easiest way to understand the causal structure of black holes is to use conformal diagrams. These show a 2-dimensional slice of the spacetime (e.g. the radial and time directions), and they have the characteristic that light rays directed in the radial direction (meaning precisely towards or away from the center of the black hole) move on straight lines at 45 degrees, and (most importantly) that any other excitation moves along a curve that is everywhere more vertical than 45 degrees. </snip>
Synthetic Black Hole Event Horizon Created in UK Laboratory Written by Ian O'Neill
Researchers at St. Andrews University, Scotland, claim to have found a way to simulate an event horizon of a black hole - not through a new cosmic observation technique, and not by a high powered supercomputer… but in the laboratory. Using lasers, a length of optical fiber and depending on some bizarre quantum mechanics, a "singularity" may be created to alter a laser's wavelength, synthesizing the effects of an event horizon. If this experiment can produce an event horizon, the theoretical phenomenon of Hawking Radiation may be tested, perhaps giving Stephen Hawking the best chance yet of winning the Nobel Prize.
So how do you create a black hole? In the cosmos, black holes are created by the collapse of massive stars. The mass of the star collapses down to a single point (after running out of fuel and undergoing a supernova) due to the massive gravitational forces acting on the body. Should the star exceed a certain mass "limit" (i.e. the Chandrasekhar limit - a maximum at which the mass of a star cannot support its structure against gravity), it will collapse into a discrete point (a singularity). Space-time will be so warped that all local energy (matter and radiation) will fall into the singularity. The distance from the singularity at which even light cannot escape the gravitational pull is known as the event horizon. High energy particle collisions by cosmic rays impacting the upper atmosphere might produce micro-black holes (MBHs). The Large Hadron Collider (at CERN, near Geneva, Switzerland) may also be capable of producing collisions energetic enough to create MBHs. Interestingly, if the LHC can produce MBHs, Stephen Hawking's theory of "Hawking Radiation" may be proven should the MBHs created evaporate almost instantly.
Hawking predicts that black holes emit radiation. This theory is paradoxical, as no radiation can escape the event horizon of a black hole. However, Hawking theorizes that due to a quirk in quantum dynamics, black holes can produce radiation.
Put very simply, the Universe allows particles to be created within a vacuum, "borrowing" energy from their surroundings. To conserve the energy balance, the particle and its anti-particle can only live for a short time, returning the borrowed energy very quickly by annihilating with each other. So long as they pop in and out of existence within a quantum time limit, they are considered to be "virtual particles". Creation to annihilation has net zero energy.
However, the situation changes if this particle pair is generated at or near an event horizon of a black hole. If one of the virtual pair falls into the black hole, and its partner is ejected away from the event horizon, they cannot annihilate. Both virtual particles will become "real", allowing the escaping particle to carry energy and mass away from the black hole (the trapped particle can be considered to have negative mass, thus reducing the mass of the black hole). This is how Hawking radiation predicts "evaporating" black holes, as mass is lost to this quantum quirk at the event horizon. Hawking predicts that black holes will gradually evaporate and disappear, plus this effect will be most prominent for small black holes and MBHs.
So… back to our St. Andrews laboratory…
Prof Ulf Leonhardt is hoping to create the conditions of a black hole event horizon by using laser pulses, possibly creating the first direct experiment to test Hawking radiation. Leonhardt is an expert in "quantum catastrophes", the point at which wave physics breaks down, creating a singularity. In the recent "Cosmology Meets Condensed Matter" meeting in London, Leonhardt's team announced their method to simulate one of the key components of the event horizon environment.
Light travels through materials at different velocities, depending on their wave properties. The St. Andrews group use two laser beams, one slow, one fast. First, a slow propagating pulse is fired down the optical fiber, followed by a faster pulse. The faster pulse should "catch up" with the slower pulse. However, as the slow pulse passes through the medium, it alters the optical properties of the fiber, causing the fast pulse to slow in its wake. This is what happens to light as it tries to escape from the event horizon - it is slowed down so much that it becomes "trapped".
"We show by theoretical calculations that such a system is capable of probing the quantum effects of horizons, in particular Hawking radiation." - From a forthcoming paper by the St. Andrews group.
The effects that two laser pulses have on eachother to mimic the physics within an event horizon sounds strange, but this new study may help us understand if MBHs are being generated in the LHCs and may push Stephen Hawking a little closer toward a deserved Nobel Prize. Source: Telegraph.co.uk
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Jose Garcia Says: February 13th, 2008 at 7:10 pm
Negative mass? Can you explain this? I've never understood how virtual particles parting ways at the horizon can remove mass from the black hole. It always seemed to me that the black hole would only get more massive as it stole these virtual particles. This is the first time I've seen negative mass mentioned.
[Bl.] Me too. I would love to understand how "something" can weigh less than nothing.I have a premonition that I'm not going to get this one...
Re:Black Hole Blow Out! New Evidence Emerges.
« Reply #8 on: 2008-02-19 18:43:34 »
[Blunderov] Or maybe the universe really is made of mathematics?
Metamagical Themeas:Questing for the Essence of Mind and Pattern Douglas R. Hofstadter ISBN0-553-34279-7 Bantam Books I have yet to succeed in comprehending/traversing the entire book cover to cover, but it has so far left no doubt in my mind, that "the universe really is made of mathematics", then the question remains who's mathematics ?
Really, George Gamow's: One, Two, Three ... Infinity, was more my style and left me with the same conclusion "the universe really is made of mathematics".
but who is counting ..... and does size matters ... arithmetic/mathematics ... it all gets stringy and to a point in the end. :-)
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