APOD: Plasma Jets from Radio Galaxy Hercules A (2012 Dec 05)

[Spif]

The density a black hole can mean different things. It is possible that the center of a black hole consists of a singularity; if so, the density there is infinite, regardless of the mass of the black hole. More generally, the density of a black hole is its mass divided by the volume within its Schwarzschild radius- a value that decreases as the mass increases. The density of the black hole in 3C 348 is less than one... it would float in a big tub of water.

Yes, a very interesting factoid ... people often don't think about just how puffy the Schwarzchild radius is for the really massive black holes! The "surface" gravity on the big black holes is surprisingly low too.

Of course, that's just an algebraic construct. It's quite possible that all black holes are actually finite compact objects that happen to fit inside their own Schwarzchild radius ... Perhaps there is a state of matter that is far more dense than a ball of degenerate baryons but which is still finite and in fact not a singularity.

-s

[Spif]

String theory, if it were to evolve into a viable and reasonably complete form, could perhaps address that new state of matter. For example, imagine if some base state of strings were the next most fundamental state of a particle below protons/quarks, then perhaps a black hole is just caused by a ball of degenerate strings? We just don't know right now and so I don't think we can predict much about what limits black holes have ... yet.

As I recall, degenerate matter results in part because the Pauli Exclusion Principle prevents the particles from all crushing together into the same point in space. If String Theory gets fleshed out, perhaps it will turn out that Strings don't have to obey the Pauli Exclusion Principle. If that were the case, perhaps all the strings in the black hole would crush down into a single co-located ball the size of a single string?

A billion solar masses inside a point far smaller than a proton... yet that's still NOT a singularity!

Just wild guesses.

-s

[Boomer12k]

My first thought was WOW, that is awesome.

Shows the power of a CMBH. One Million Light Years Long, WOW. (We should have someone redo the 1960's movie "One Million Years B.C.", only make it a sci-fi movie, (One Million Light Years, AD.) I know, I know. Light years is distance, but to travel distance is also time, and it is a PLAY ON WORDS, a PARODY if you will.

Why does the one on the right look like a SMILEY FACE? Or why does it look like a woman's....um....torso?

I could also make another comment about "GAS", but my comment would be removed no doubt.

Thanks for the picture!!!

:---[===] *

[neufer]

Click to play embedded YouTube video.

Can anyone tell me why it appears that these jets are diffusing from their initially narrow jet into giant balls where the plasma appears to be meeting some kind of drag and slowing down ? It looks like what you'd expect to see if you were releasing steam from a valve under pressure into a large space - an initially tight high speed jet diffusing and cooling into a large space. This isn't some kind of cosmic Joule Thomson effect is it ?

• I'm staring at you right now,
  Strangerbarry, just like Ethan here

It's more like a cosmic gold foil Geiger–Marsden experiment.
Check out: http://asterisk.apod.com/viewtopic.php? ... 11#p188915 above.

[Guest]

Thanks, guys, you made me remember a video I saw a while ago talking about quantum mechanics taking over at that point in black holes and how it would connect to the physical world (theoretically). I'm paraphrasing and probably not making any sense but I believe that was what you were alluding to in your replies.

[Mook Skywalker]

I am not a boring over-analytical scientist. But I am a poet. To me those gargantuan lobes look like placenta. Perhaps they have imaged the fabled womb of the universe. Go ahead Poindexter...prove me wrong.

[Chris Peterson]

I am not a boring over-analytical scientist. But I am a poet.

And I'm not a boring poet, but rather a scientist.

[Ann]

I am not a boring over-analytical scientist. But I am a poet.

And I'm not a boring poet, but rather a scientist.

And I am a poet of blue things, trying to understand their beauty in scientific terms and trying to describe them, when necessary, in boring scientific terms. Plus, I like the impudent super-duper-over-vastness of the cosmos.

Radio waves, well... they don't tickle me, because they aren't even almost colored, and they didn't even start out as colored light. But I do like galaxies.

And Hercules A reminds me of Perseus A. I like how the entire "cosmic environment" around Perseus A is "ringing like a bell" because of the ongoing collision between two galaxies and the terrific cosmic crash-bang that makes. Read more about it here. Of course, when it comes to jets, Hercules A more resembles Cen(taurus) A than Perseus A, although Hercules A is clearly more titanic.

Ann

[Boomer12k]

Ann,

I never find you boring. Your insights into why things are blue, (and your quirkiness with it), is fascinating.

Boomer.

:---[===] *

[rstevenson]

...
Consider then a couple of scenarios about the probability of successful abiogenesis and what the universe might look like under those scenarios. ...

Two things you might want to have a look at which bear on this issue: the Drake Equation, which is a tool for estimating "the number of detectable extraterrestrial civilizations in the Milky Way galaxy," and the Fermi Paradox, which isn't really a paradox; it's just the question, "Where is everybody?".

Depending on how optimistic I'm feeling (which in turn depends on what I had for breakfast) I get an answer that can range from 10 to 100,000 using the Drake Equation, an answer which just brings me back to Fermi's question. Perhaps all we can conclude is that we're the first civilization that may (if we're very, very smart about fixing our current problems) eventually fill up the Milky Way galaxy. Or not.

Rob

[starsurfer]

Hi guys, is it me or do those jets look like they are turning counter clockwise?
The jet on the left coming towards us and the right one travelling away.

No I think that is an illusion. If that was the case, the left jet would appear blueshifted and the right one redshifted and if that was the case, then that would definitely have been mentioned in the article. However, I might be wrong as I haven't read the related paper (assuming there is a corresponding paper).

The radio jet structure is simply a monochrome black & white radio wave intensity map that is color coded magenta to distinguish it from the Hubble background.

Besides which, there are no spectral lines to blue-shift or red-shift since the continuous synchrotron radiation comes from "relativistic electrons spiraling through magnetic fields."

The source black hole could well be slowly precessing so as to cause the slow moving jet exit regions to have the sort of "water spray" slow turning features that Horus suggests (or it could be simply an illusion as starsurfer suggests).

Thanks for the informative reply! I know hardly anything about radio galaxy jets, so I wish to apologise for misleading anyone with my rare episode of assuming a fact rather than actually reading it up and giving a reply based on genuine truth.

[Spif]

Hi guys, is it me or do those jets look like they are turning counter clockwise?
The jet on the left coming towards us and the right one travelling away.

No I think that is an illusion. If that was the case, the left jet would appear blueshifted and the right one redshifted and if that was the case, then that would definitely have been mentioned in the article. However, I might be wrong as I haven't read the related paper (assuming there is a corresponding paper).

What you may be seeing is there could likely be a prevailing wind that is blowing the slowed ends of the jets back. Both the ambient gas and the galaxy are moving relative to the local cluster and that can induce a drift once the gas in the jets slows through multiple collisions.

[Alfred]

"Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center."

Can anyone please try and describe the concequences of such a massive Central black hole in our Milky Way galaxy? Would it be possible to live on Earth?

[Spif]

"Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center."

Can anyone please try and describe the concequences of such a massive Central black hole in our Milky Way galaxy? Would it be possible to live on Earth?

We have a large central black hole in our galaxy but it is only on the order of 1 million solar masses rather than the billion solar masses of the galaxy in the APOD picture above. Also, our black hole is relatively quiet while the one in Hercules A is busy actively ingesting lots of material that is falling into it. Ours was presumably active in the past but is apparently mostly done eating.

I believe active massive black holes emit most of their dangerous radiation in jets out the poles. There may be heightened cosmic ray radiation around the center of such a galaxy too, but I think not enough to be dangerous to the mid to outer reaches where life is most likely to evolve in a galaxy. Active black holes also emit a lot of X-ray light from their accretion disks but that is only dangerous when close and much of that I believe gets attenuated by a ring cloud of dust that snuggles up close to the black hole. So the central black holes are pretty much only dangerous up close and at any distance along the polar axes.

A misconception that some people have is that black hole gravity is somehow dangerous or far reaching. In fact that is not true. Black hole gravity is only dangerous around the event horizon. If our sun were a black hole, we could orbit it and get along just fine (aside from the lack of luminous emission).

[Ann]

"Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center."

Can anyone please try and describe the concequences of such a massive Central black hole in our Milky Way galaxy? Would it be possible to live on Earth?

My gut feeling is that such a titanic black hole would indeed be dangerous, mostly because of the incredible jets it spews out. And if the black hole is rotating or the jets are precessing, then maybe very large parts of that galaxy regularly get showered by whatever nasty radiation or energetic particles or the like are found in those jets. I wouldn't like being on the receiving end of such a jet in the Milky Way. All things considered, I believe that huge black holes are dangerous, mostly because they have such cosmic outbursts when they eat.

Ann

[muffin]

a bit late to the debate -

question from a non-astronomer: the 2 jets look a lot like cigarette smoke, especially the left one. does that mean that the same laws [or descriptions?] of turbulence are going on here? it seems pretty remarkable to find the similarity.. it doesnt look like there's self-similar patterning inside the puffs..

[BMAONE23]

I would think that IF the jets were Polar and IF the poles pointed perpendicular to the galaxy disk and IF the host galaxy were a disk with a planar stellar galactic orbit, then the odds of life being there are far greater than in the chaotic orbits within an elliptical galaxy. Orbits within elliptical galaxies would tend to have a far greater chance of encountering the radiation from the jets

[Alfred]

"Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center."

Can anyone please try and describe the concequences of such a massive Central black hole in our Milky Way galaxy? Would it be possible to live on Earth?

We have a large central black hole in our galaxy but it is only on the order of 1 million solar masses rather than the billion solar masses of the galaxy in the APOD picture above. Also, our black hole is relatively quiet while the one in Hercules A is busy actively ingesting lots of material that is falling into it. Ours was presumably active in the past but is apparently mostly done eating.

I believe active massive black holes emit most of their dangerous radiation in jets out the poles. There may be heightened cosmic ray radiation around the center of such a galaxy too, but I think not enough to be dangerous to the mid to outer reaches where life is most likely to evolve in a galaxy. Active black holes also emit a lot of X-ray light from their accretion disks but that is only dangerous when close and much of that I believe gets attenuated by a ring cloud of dust that snuggles up close to the black hole. So the central black holes are pretty much only dangerous up close and at any distance along the polar axes.

A misconception that some people have is that black hole gravity is somehow dangerous or far reaching. In fact that is not true. Black hole gravity is only dangerous around the event horizon. If our sun were a black hole, we could orbit it and get along just fine (aside from the lack of luminous emission).

There is a factor 1000 mentioned with regards to the size of the central black hole and the size of the Galaxy... Is there any evidence to suggest that big black holes reside in big galaxies, and vice versa? I assume Our sun would be racing at great speeds becauce of the gravity from the black hole monster?

[Alfred]

"Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black hole at our Milky Way's center."

Can anyone please try and describe the concequences of such a massive Central black hole in our Milky Way galaxy? Would it be possible to live on Earth?

My gut feeling is that such a titanic black hole would indeed be dangerous, mostly because of the incredible jets it spews out. And if the black hole is rotating or the jets are precessing, then maybe very large parts of that galaxy regularly get showered by whatever nasty radiation or energetic particles or the like are found in those jets. I wouldn't like being on the receiving end of such a jet in the Milky Way. All things considered, I believe that huge black holes are dangerous, mostly because they have such cosmic outbursts when they eat.

Ann

What sort of motion would / could make the massive black hole "wobble"?

[neufer]

[b][color=#0000FF]Radio image of the galaxy NGC 326, a prototypical X-shaped radio source. The active lobes are oriented from lower left to upper right; the wings are the lower surface brightness lobes oriented from upper left to lower right. The inset shows the jets of radio-emitting particles that are being ejected from the supermassive black hole, and which are believed to power the active lobes. Credit: NRAO / AUI, observers Murgia et al. Inset: STScI[/color][/b]

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What sort of motion would /
could make the massive black hole "wobble"?

<<A black hole spin-flip occurs when the spin axis of a rotating black hole undergoes a sudden change in orientation due to absorption of a second (smaller) black hole. Spin-flips are believed to be a consequence of galaxy mergers, when two supermassive black holes form a bound pair at the center of the merged galaxy and coalesce after emitting gravitational waves. Spin-flips are significant astrophysically since a number of physical processes are associated with black hole spins; for instance, jets in active galaxies are believed to be launched parallel to the spin axes of supermassive black holes. A change in the rotation axis of a black hole due to a spin-flip would therefore result in a change in the direction of the jet.

Black hole spin-flips were first discussed in the context of a particular class of radio galaxy, the X-shaped radio sources. The X-shaped galaxies exhibit two, misaligned pairs of radio lobes: the "active" lobes and the "wings". It is believed that the wings are oriented in the direction of the jet prior to the spin-flip, and that the active lobes point in the current jet direction. The spin-flip could have been caused by absorption of a second black hole during a galaxy merger.>>

[BMAONE23]

It would seem to me that to have a "Wobble" motion to the BH rotation, or even a Toroid shape encircling the "Equatorial" region of the BH implies that the beast must have a measurable size to allow for an equatiroal region to exist. Then to have Polar jet features might further imply the existance of dipolar magnetism. If this were a true singularity it would almost certainly need to be monopolar. This would suggest that BH's, within the Event Horizon, have both mass and measurable size and aren't singularities.

[Greg Hilton]

If each jet is 1M light years in size, then the whole structure is roughly 2M light years across. It would seem like this makes it one of the largest coherent structures in the universe. Is this true? (Even though they are gravitationally bound, I would not classify galactic clusters or superclusters as coherent structures. Colliding/merging galaxies, yes.)

[Spif]

There is a factor 1000 mentioned with regards to the size of the central black hole and the size of the Galaxy... Is there any evidence to suggest that big black holes reside in big galaxies, and vice versa? I assume Our sun would be racing at great speeds becauce of the gravity from the black hole monster?

Yes, up until recently, it has been generally found that there is an apparent correlation between galaxy mass and the mass of the central black hole. However, a paper just came out that found an extreme distance (very early) small galaxy with a disproportionately large central black hole. This surprises and disturbs galactic evolution astronomers... is it a weird anomaly or is there something very wrong with our assumptions of how galaxies and central black holes evolve? We don't know yet... so now they're on the hunt for more of these cases.

But as I understand it, in terms of recent (nearby) galaxies, there is generally a correlation.

-s

[Spif]

It would seem to me that to have a "Wobble" motion to the BH rotation

I've never heard of black holes (really, their magnetic fields) precessing. All of the active nuclei examples I've seen have been stable straight jets with sizes on the order of 1M light years, implying that they are rock steady for long periods of time. But my Astrophysics is undergrad and was from 20 years ago, so take counter point with a grain of salt.

or even a Toroid shape encircling the "Equatorial" region of the BH implies that the beast must have a measurable size to allow for an equatiroal region to exist.

I think references to "equatorial" regions are usually in reference to the zone away from the poles where the jets flow out. The accretion disk (not part of the black hole) tends to align with the equatorial spin I think. And then outside of that there is a ring of dust that usually obscures the fun part of the accretion disk where the black hole ingests matter.

Black holes and their event horizons I think are always very close to spherical. But I've seen an animation of a model of merging black holes where they were expected to become squat ellisoids. Perhaps that squishing of the shape might be a function of space time distortions around the extreme gravity between the black holes and perhaps the model does not necessarily require there to be a finite shape or structure within the event horizon?

-s

[Roger]

The galaxy is also known as PGC 59117, and is of visual magnitude 17.8. It appears to be the largest galaxy in a dense cluster. Although this is within reach of amateur astrophotographers, it would be tiny on their CCD chips, so most amateurs leave such distant objects alone. So, the Hubble view is shown. (Of course, the radio jets would not show up in CCD images.)