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Milky Way's Black Hole a Gamma Source?
eldavojohn writes "A paper recently accepted for publication (preprint here) proposes a sound explanation for the source of the gamma rays that permeate our galaxy. The Milky Way's central object Sagittarius A*, widely believed to be a supermassive black hole, is now suspected to be the source. To test this theory, two scientists created a computer model to track the protons, flung outward with energies up to 100 TeV by the intense magnetic fields near the event horizon, as they make a random walk through the plasma environment. It can take thousands of years for them to travel 10 light-years from the black hole, where they collide with lower-energy protons to form pions. These decay into gamma radiation emanating from a torus-shaped region around the central object."
Hulk!
"The Milky Way's central object Sagittarius A* [CC], widely believed to be a supermassive black hole, is now suspected to be the source."
Would that make it an "A-Hole" ?????
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
I always knew I was more powerful because of my astrological sign. Now I have proof!
Or proof that my life sucks... either way, it's something!
The Milky Way's central object Sagittarius A*, widely believed to be a supermassive black hole, is now suspected to be the source.
That black hole must really suck.
Long Shot is ready for departure
That's no black hole!
"Oh boy"
I thought the background gamma radiation was from the big bang and thus older than the galaxies?
Libertarian Leaning Political Discussion Forum.
I wonder if that means that life is only possible near the outer arms of the galaxy? If you assume that gamma rays are a point source in the middle of our galaxy, what sort of radiation levels are you going to see closer to the center?
What does God need with a starship?
Slashdot Burying Stories About Slashdot Media Owned
I've been semi-interested in Cosmology/Astrophysics lately, and from everything I've seen and read so far, I've ascertained that we don't know much. Between dark matter, dark energy, gravity, black holes, big bang, etc. it seems like we just conveniently make up "stuff" to fit some model or equation. Do discoveries like this mean anything at this time considering there's no way to prove any of it?
Super massive black hole?! That SUCKS!!
I don't want Karma, I just want to be a smart ass. All in favor, mod me up.
Is this the object at the center of the galaxy? A while back someone posted a link to video of a star orbiting the center of our galaxy. It had a period of about 10 (11 or 12?) years and a closest approach to the black hole at a distance similar to the orbital radius of pluto. Since this star is observable and much closer to the black hole than 10 light years, it seem improbable that photons take a "random walk" out to a distance of 10 light years. That would make said star unobservable - wouldn't its light be spread all over the place? Or is the actual path not truely random, and the light is just delayed? Can someone explain the apparent discrepancy in this theory and the observed star?
It's time to cue the Goatse jokes and links! Let's give 'em hell boys!
-"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
I could've swore that Science Channel (US) already did a special on the Gamma Ray bursts that permeate our UNIVERSE . They concluded it was from distant, very distant galaxies that were elliptical, and rather young, but they had stated that the bursts were coming from SMBH's. While we do have a SMBH at the center of our galaxy, as do all galaxies, ours is currently not being 'fed'. Much of the mass nearby the SMBH has already been absorbed, or whatever the word would happen to be, by it leaving quite a large distance between it and any thing that could cause these Gamma ray bursts.
I've been semi-interested in Computer Science/Mathematics lately, and from everything I've seen and read so far, I've ascertained that we don't know much. Between dark fiber, optimal algorithms, P=NP, O(n log n) (and other equations like that), cryptography, etc. it seems like we just conveniently make up "stuff" to fit some model or equation. Do discoveries like this mean anything at this time considering there's no way to prove any of it?
[No offense intended--just pointing out that a lack of sophisticated understanding in a field of study does not imply the field is in any way bogus or the knowledge is "shaky". The reason it's called "dark matter" or "dark energy" is precisely because we aren't sure exactly what it is yet.]
it's a blue bright blue Saturday hey hey
The summary makes it sound as though this is an explanation for the DIFFUSE gamma-ray emission seen in our Galaxy. This is not the case, the paper only discuss a source of gamma-rays observed to be spatially coincident with the Galactic center. Gamma-ray telescopes do not have high angular resolution so there is a possibility that the gamma-rays are not actually coming from the Galactic center in the first place. Finally this is not a new proposal. Proton acceleration near black holes is quite commonly discussed and accepted. Furthermore photo-pion production is a well known process that has been well measured in the lab. I think the real meat of this paper is that they are suggesting observations of emission associated with the black hole that we have observed gravitationally for a while now. This is the big news, not that the gamma-rays in our galaxy have been explained, not that protons make pions which decay into gamma-rays.
Pinball on a Galactic Scale By Phil Berardelli ScienceNOW Daily News 28 February 2007 The center of our Milky Way galaxy crackles with lethal gamma-rays, emitting trillions of electron volts of energy. Yet most astrophysicists consider our corner of the universe a relatively placid place, so the source of all this energy has remained mysterious. Now, members of an international team think they have found the answer: high-energy protons ejected by the supermassive black hole that lies at the heart of the galaxy. In 1998, scientists confirmed what they had long suspected: The Milky Way's center hosts an immense black hole, equivalent to the mass of about 2.6-million suns. Like all black holes, it pulls in huge amounts of matter to its ultimate doom. But when compared to the hearts of other galaxies, the Milky Way's hole had been considered puny, with not enough mass to generate much radiation in the gamma-ray wavelengths. Nevertheless, in 2004, astronomers found that the black hole was indeed generating gamma-rays, thereby forcing a search for the mechanism that could produce them. That mechanism appears to be magnetism. Reporting in this week's issue of Astrophysical Journal Letters, a team led by David Ballantyne of the University of Arizona in Tucson concludes that the Milky Way's central black hole is strong enough to generate a powerful but chaotic magnetic field that extends out a distance of about 10 light-years. To reach their conclusions, the researchers used computer programs to calculate the hypothetical trajectories of some 220,000 protons, which are ejected from the Milky Way's black hole and get bounced around by its magnetic field like in a galactic-sized version of a pinball machine. They then compared those paths with recent observations by ground-based instruments of the location of the gamma-rays and found that 69% of the computer-generated trajectories matched what the observed data were showing. The protons were slamming into hydrogen atoms within huge clouds of gas that slowly orbit the black hole about 10 light-years out. These collisions produce the gamma radiation astronomers have observed at the center of the Milky Way. Co-researcher Fulvio Melia, also of the University of Arizona, says the findings could help astrophysicists understand how the most powerful black holes in the universe likewise produce gamma radiation. "The same particle slinging almost certainly occurs in all black-hole systems," Melia says. The findings are interesting, but not necessarily conclusive, says astrophysicist Valerie Connaughton of NASA's Marshall Space Flight Center in Huntsville, Alabama. There could be an alternative explanation, such as a recent supernova in the vicinity of the galactic center, she says, which could be accelerating the high-energy protons being detected. Further observations are needed, she says, because "we still don't really understand all of the physics involved."
Pinball on a Galactic Scale
By Phil Berardelli
ScienceNOW Daily News
28 February 2007
The center of our Milky Way galaxy crackles with lethal gamma-rays, emitting trillions of electron volts of energy. Yet most astrophysicists consider our corner of the universe a relatively placid place, so the source of all this energy has remained mysterious. Now, members of an international team think they have found the answer: high-energy protons ejected by the supermassive black hole that lies at the heart of the galaxy.
In 1998, scientists confirmed what they had long suspected: The Milky Way's center hosts an immense black hole, equivalent to the mass of about 2.6-million suns. Like all black holes, it pulls in huge amounts of matter to its ultimate doom. But when compared to the hearts of other galaxies, the Milky Way's hole had been considered puny, with not enough mass to generate much radiation in the gamma-ray wavelengths. Nevertheless, in 2004, astronomers found that the black hole was indeed generating gamma-rays, thereby forcing a search for the mechanism that could produce them.
That mechanism appears to be magnetism. Reporting in this week's issue of Astrophysical Journal Letters, a team led by David Ballantyne of the University of Arizona in Tucson concludes that the Milky Way's central black hole is strong enough to generate a powerful but chaotic magnetic field that extends out a distance of about 10 light-years. To reach their conclusions, the researchers used computer programs to calculate the hypothetical trajectories of some 220,000 protons, which are ejected from the Milky Way's black hole and get bounced around by its magnetic field like in a galactic-sized version of a pinball machine. They then compared those paths with recent observations by ground-based instruments of the location of the gamma-rays and found that 69% of the computer-generated trajectories matched what the observed data were showing. The protons were slamming into hydrogen atoms within huge clouds of gas that slowly orbit the black hole about 10 light-years out. These collisions produce the gamma radiation astronomers have observed at the center of the Milky Way.
Co-researcher Fulvio Melia, also of the University of Arizona, says the findings could help astrophysicists understand how the most powerful black holes in the universe likewise produce gamma radiation. "The same particle slinging almost certainly occurs in all black-hole systems," Melia says.
The findings are interesting, but not necessarily conclusive, says astrophysicist Valerie Connaughton of NASA's Marshall Space Flight Center in Huntsville, Alabama. There could be an alternative explanation, such as a recent supernova in the vicinity of the galactic center, she says, which could be accelerating the high-energy protons being detected. Further observations are needed, she says, because "we still don't really understand all of the physics involved."
Of course. Life evolves to fit the current conditions. In a high radiation environment, I can imagine a life form that takes advantage of the high radiation levels to rapidly mutate and evolve, increasing its chances of survival in a hazardous environment. Actually, there are plants on this very planet that for some reason have developed the abilty to mutate rapidly. The hawthorn for example. There was a point when there were hundreds of named species of hawthorn. Before the botanists realized the damned things were just mutating spontaneously.
Tardigrades [aka Water Bears], which live everywhere on this planet Earth, can...
1) resist storage in liquid nitrogen
2) survive in contact with mineral acids, organic solvents, and boiling water
3) survive in a a vacuum and under high pressure
4) withstand ionizing radiation of over 600,000 roentgens (500 roentgens would be fatal to a human)
It sucks AND blows!
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
are coming...
Over twenty years ago, physicist Paul LaViolette stated that gamma rays emanate from the center of the galaxy. (See prediction 12 at the link)
Or so it appears, according to the subatomic particles God set in motion "already on their way", when creating the universe 6000 years ago.
Dumbass scientists. >:(
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
so what im gathering is that black holes take in everything (time/space/light..etc) but emit gamma rays??????
What does the Gay Married Men Association have to do with this A*-hole? Oh, wait, never mind...
Get ready to recieve my Hot Needle of Inquiry.
Prepare to receive my Hot Needle of Inquiry. (I put it in a reply to a lower post but it's too good a line to leave hidden :P)
In Soviet Korea.....
http://ftw.generation.no/img/sovietkorea.jpg
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
I can see how this would work. If my desktop gets too dark and I can't see things properly, I adjust the gamma.
Even I winced at that one.
Mod parent down, the link is to Goatse.