Ghostly gamma-ray beams blast from Milky Way's center

May 29, 2012
This artist's conception shows an edge-on view of the Milky Way galaxy. Newly discovered gamma-ray jets (pink) extend for 27,000 light-years above and below the galactic plane, and are tilted at an angle of 15 degrees. Previously known gamma-ray bubbles are shown in purple. The bubbles and jets suggest that our galactic center was much more active in the past than it is today. Credit: David A. Aguilar (CfA)

( -- As galaxies go, our Milky Way is pretty quiet. Active galaxies have cores that glow brightly, powered by supermassive black holes swallowing material, and often spit twin jets in opposite directions. In contrast, the Milky Way's center shows little activity. But it wasn't always so peaceful. New evidence of ghostly gamma-ray beams suggests that the Milky Way's central black hole was much more active in the past.

"These faint jets are a ghost or after-image of what existed a million years ago," said Meng Su, an astronomer at the Harvard-Smithsonian Center for Astrophysics (CfA), and lead author of a new paper in the .

"They strengthen the case for an active in the Milky Way's relatively recent past," he added.

The two beams, or jets, were revealed by NASA's Fermi . They extend from the to a distance of 27,000 light-years above and below the . They are the first such gamma-ray jets ever found, and the only ones close enough to resolve with Fermi.

The newfound jets may be related to mysterious gamma-ray bubbles that detected in 2010. Those bubbles also stretch 27,000 light-years from the center of the Milky Way. However, where the bubbles are perpendicular to the galactic plane, the gamma-ray jets are tilted at an angle of 15 degrees. This may reflect a tilt of the surrounding the .

"The central accretion disk can warp as it spirals in toward the black hole, under the influence of the black hole's spin," explained co-author Douglas Finkbeiner of the CfA. "The embedded in the disk therefore accelerates the jet material along the spin axis of the black hole, which may not be aligned with the Milky Way."

The two structures also formed differently. The jets were produced when plasma squirted out from the galactic center, following a corkscrew-like magnetic field that kept it tightly focused. The gamma-ray bubbles likely were created by a "wind" of hot matter blowing outward from the black hole's accretion disk. As a result, they are much broader than the narrow jets.

Both the jets and bubbles are powered by inverse Compton scattering. In that process, electrons moving near the speed of light collide with low-energy light, such as radio or infrared photons. The collision increases the energy of the photons into the gamma-ray part of the electromagnetic spectrum.

The discovery leaves open the question of when the Milky Way was last active. A minimum age can be calculated by dividing the jet's 27,000-light-year length by its approximate speed. However, it may have persisted for much longer.

"These jets probably flickered on and off as the supermassive black hole alternately gulped and sipped material," said Finkbeiner.

It would take a tremendous influx of matter for the galactic core to fire up again. Finkbeiner estimates that a molecular cloud weighing about 10,000 times as much as the Sun would be required.

"Shoving 10,000 suns into the black hole at once would do the trick. Black holes are messy eaters, so some of that material would spew out and power the jets," he said.

Explore further: NASA missions monitor a waking black hole

Related Stories

The Milky Way's supermassive black hole

Aug 08, 2011

Supermassive black holes - objects with masses of millions or even billions of suns - are found at the nuclei of galaxies. Our Milky Way galaxy, for example, has a massive black hole at its core, albeit one ...

The power of spin

Jan 28, 2011

( -- Supermasssive black holes - objects with masses of millions or billions of suns - are found at the nuclei of dramatic galaxies like quasars where they are responsible for some of the most ...

Black hole jets

Jan 16, 2012

( -- 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 ...

Chandra finds fastest wind from stellar-mass black hole

Feb 21, 2012

Astronomers using NASA's Chandra X-ray Observatory have clocked the fastest wind yet discovered blowing off a disk around a stellar-mass black hole. This result has important implications for understanding ...

Recommended for you

NASA missions monitor a waking black hole

2 hours ago

NASA's Swift satellite detected a rising tide of high-energy X-rays from the constellation Cygnus on June 15, just before 2:32 p.m. EDT. About 10 minutes later, the Japanese experiment on the International ...

What is the habitable zone?

11 hours ago

The weather in your hometown is downright uninhabitable. There's scorching heatwaves, annual tyhpoonic deluges, and snow deep enough to bury a corn silo.

Galaxy survey to probe why the universe is accelerating

12 hours ago

We know that our universe is expanding at an accelerating rate, but what causes this growth remains a mystery. The most likely explanation is that a strange force dubbed "dark energy" is driving it. Now a ...

High resolution far-infrared all-sky image data release

13 hours ago

A research group led by a University of Tokyo researcher, using the AKARI satellite's Far-Infrared All-Sky data, have created all-sky image maps and released the full database to researchers around the world ...

User comments : 16

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (12) May 29, 2012
IMO the galactic center is active all the time - it just emanates the solitons of light (gamma rays) and gravitational waves (neutrinos), which do recombine mutually into particles of matter, which is evaporated from central black hole in this way. The existence of jets demonstrates, the event horizon of central black hole is still thinner at its poles, so that less massive particles can penetrate trough it. In this sense the central black holes is behaving like giant neutrino pulsar. IMO the lobes are remnants of dark matter condensing from jets, which are spreaded with precession of the jets in analogy with the picture bellow


The steady state model of Universe of dense aether theory needs the mechanism of black hole evaporation (faster than the Hawking radiation), because without it the Universe would be full of black holes already and no matter would be recycled.
1 / 5 (12) May 29, 2012
In my opinion the emanation of neutrino jets is very common at the case of massive stars - I presume, even the Sun emanates the hidden streams of neutrinos through its poles. We have observational evidence of these streams already
1 / 5 (7) May 29, 2012
The Big Bang was a two-jet (two lobe) event.
1 / 5 (9) May 29, 2012
Sounds like a concession by mainstream cosmologists? This was unthinkable just a few months ago. Check my comments in the earlier news.

Looks like LaViolette is correct. Check his explanation, dating to his dissertation in the early 80's.


And the Crab pulsar is the most dramatic evidence of a recent superwave passing some 12,000 years ago.


So if LaViolette turns out to be correct, what does that say about all the doubters on this board?? How smart are they in reality?? Embarrassment is coming. Get your rationalizations ready to go!

1 / 5 (10) May 29, 2012
The second link is LaViolette's Fermi Bubble explanation:


1 / 5 (7) May 29, 2012
Looks like LaViolette is correct.
The question is, if these lobes are product of some periodic eruptions (as LaViolette considers) or if they're steady state. From the article it seems, they're steady state, which would correspond my ideas better.
4.3 / 5 (9) May 29, 2012
since tuxford has felt the need to promote laviolette's theory in every astronomy article possible i feel i should show just what it is we are dealing with when it comes time to consider laviolettes cosmological theories.
here are some works from tuxfords idol laviolette, it illustrates how based in reality his worldview really is.this is a book he wrote.
First time proof of the existence of interstellar radio signals of intelligent origin being sent to us.
Evidence that pulsars are part of a vast network of ETI communication beacons.
This exhaustive study presents first time proof that astronomers have been receiving radio signals of intelligent origin. As early as 1967 and continuing to the present, radio astronomers have been carefully studying and cataloging unusual interstellar beacons called pulsars thinking them to be stars of natural origin.Dr. LaViolette, who has been researching pulsars for 27 years, shows that, up to now, the nature of these radio sources has been grossly
5 / 5 (8) May 29, 2012
misunderstood. He has discovered that a number of very unique pulsars are nonrandomly distributed in the sky and mark key Galactic locatations that have particular significance from an ETI communication standpoint. He also presents evidence of unusual geometric alignments among pulsars and intriguing pulse period relationships. Equally compelling is the message they are sending-a warning about a past Galactic core explosion disaster that should help us avert a future global tragedy.

Contains extensive analysis of pulsar data, revealing new ideas about the origins and functions of pulsars

Provides proof of an extraterrestrial communication network

Includes information about the formation of crop circles and force-field-beaming technology
5 / 5 (8) May 29, 2012
see, this is what i mean about science fiction fantasy based worldview that laviolette employs in his cosmological theories. and all the others fields of science he's claimed to make breakthroughs in because of it while having no training in the fields he claims to have proven wrong.
1.4 / 5 (9) May 29, 2012
If we look closely to some gamma ray snapshots from the above article, we can see, that the gama ray beams form sorta bundle of beams, which could indicate, the formation of jets is really periodic discontinuous process in accordance to this animation and LaViolette hypothesis. It's still very rough speculation, though - we would need a way better data to falsify it.
1 / 5 (8) May 29, 2012
In my opinion the global warming manifests across whole solar system and it was initiated with dense cloud of interstellar gas or dark matter, passing through solar system right now. It would be nice if the activity of central region of Milky Way could explain it. But there are many other possible sources of dark matter: the shielding of galactic core with Dark Rift, the passing of Solar system through interstellar gas at galactic plane and/or dark matter trapped with invisible yet massive object visiting the Solar system from Oort cloud.
4.5 / 5 (8) May 29, 2012
The steady state model of Universe of dense aether theory needs the mechanism of black hole evaporation

First I think it needs peer review.
5 / 5 (5) May 30, 2012
The steady state model of Universe of dense aether theory needs the mechanism of black hole evaporation

First I think it needs peer review.

Only scientific stuff needs peer review. When stuff is so obvious as condensed whatever... and neutron whatchamacallit you can just write using spray cans on walls cause its really true.

At the end of the day, I suspect a good deal of neutrino based brain damage has occurred to some of our less informed posters.
1 / 5 (2) Jun 28, 2012
First I think it needs peer review.
Peer review is necessary for people, who are doing science for money to avoid apparent frauds. I don't require neither expect any money for my ideas. BTW The people who aren't able to judge foreign ideas without peer-review aren't interesting for me anyway - such a people are simply religious sheep in my eyes, who cannot think in independent way until someone else bring categorical stance about it. For example the cold fusion was refused in peer-review repeatedly and now we're facing megawatt device working - such a peer review is just a parody of scientific method.
I suspect a good deal of neutrino based brain damage has occurred
IMO neutrinos can really contribute to the instability of human mind during various conjunctions of planets and eclipses ("full moon" effect). But the above mechanism points rather to the superluminal neutrino model, which was revealed in Opera experiment first, but later retracted under strange circumstances.
1 / 5 (1) Jun 28, 2012
I've two reasons for to consider the outcome of the OPERA experiments rather suspicious.

1) We have read, that the misinterpretation of OPERA results were caused with two errors, one has lead to the positive deviation, the second one has lead to the negative deviation. At the end of the whole story suddenly only one source of experimental failure (i.e. loose optical cable) was considered - why?

2) The poor connection of optical cable doesn't explain the published dependence of the neutrino delay on neutrino energy, which fits the previous experimental finding quite well. It seems for me, one of the sets of results was essentially fabricated and now the only question is, which one: the first published one - or the "correction", released six months later?
1 / 5 (1) Jun 28, 2012
At any case, if we allow to "suck the energy" from black holes in form of massive particles, i.e. with axions or even with neutrinos directly, it may lead into significant evaporation of black holes, which will surpass the rather slow and weak Hawking mechanism in many orders of magnitude. The fact, that young galaxies have massive and radiative black holes whereas old galaxies have quiet and small black holes points to the gradual evaporation of central black holes too. Very old galaxies are elliptical and the geometry of central black hole apparently plays no role for them. Many dwarf galaxies are considered a remnant of older galaxies and they lack the black holes completely.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.