Image: Hot gas sloshing in a galactic cauldron

Nov 19, 2013
Credit: E. O’Sullivan & ESA

(Phys.org) —Galaxies are social beasts that are mostly found in groups or clusters – large assemblies of galaxies that are permeated by even larger amounts of diffuse gas. With temperatures of 10 million degrees or more, the gas in galaxy groups and clusters is hot enough to shine brightly in X-rays and be detected by ESA's XMM-Newton X-ray observatory.

As galaxies speed through these gigantic cauldrons, they occasionally jumble the gas and forge it into lop-sided shapes. An example is revealed in this composite image of the galaxy group NGC 5044, the brightest group in X-rays in the entire sky.

The group is named after the massive and bright at its centre, surrounded by tens of smaller spiral and dwarf galaxies. The galaxies are shown in a combination of optical images from the Digitized Sky Survey with infrared and ultraviolet images from NASA's WISE and Galex satellites, respectively. Foreground stars are also sprinkled across the image.

The large blue blob shows the distribution of hot gas filling the space between NGC 5044's galaxies as imaged by XMM-Newton. From the X-ray observations, astronomers can also see the glow of that were forged in stellar explosions within the of the group but streamed beyond. The distribution of iron atoms is shown in purple.

Embedded within the hot gas are clouds of even more energetic plasma that emit radio waves – a reminder of the past activity of a lurking at the centre of the group. These are the green filament extending from the central galaxy to the lower right and the larger green region to its lower left, which were imaged with the Giant Metrewave Radio Telescope, near Pune in India.

The distribution of the intergalactic gas and its ingredients is asymmetric, with a larger splotch in the upper right part of the image and a smaller one in the lower left.

Astronomers believe that gas in NGC 5044 is sloshing as a consequence of a galaxy that passed through it several millions of years ago. The culprit is the spiral galaxy NGC 5054, which is not visible here, instead hiding beyond its lower left corner.

The transit of NGC 5054 through the centre of the group may have also caused the twisted shape of the radio-bright filament.

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cantdrive85
1 / 5 (14) Nov 19, 2013
Plasma doesn't "slosh", such a notion is remarkably ridiculous.
Tuxford
1 / 5 (12) Nov 19, 2013
And the merger mania continues…After all, what else could cause such a mash-up???? The enormous gray hole at the center of the giant elliptical, the final growth stage of galaxies, perhaps. Mass begets mass, and more core activity, ejecting new matter therefrom. Another clue is the iron having been found in the jets of a black hole. The entire region is seeded with iron. We know that jets have relativistic speeds, and extreme range.

http://phys.org/n...ack.html

Nah…let the mania continue in the fanciful minds of modern astronomers.
Ewan OSullivan
2.6 / 5 (10) Nov 19, 2013
Tuxford, while Iron-enriched gas is seen along the jets coming from some supermassive black holes, in this case the Iron is actually anti-correlated with the jet and detached radio lobe. In the image above the Iron is in purple, and the jet/lobe is in green, so the radio lobe falls in an area of low Iron abundance. Also, since the Iron-enriched gas extends much further to the lower left than the radio structure, it seems very unlikely that jet activity could have produced the Iron distribution we see.

cantdrive85: Perhaps you'd prefer to say it oscillates?
Tuxford
1 / 5 (11) Nov 19, 2013
EOS, nice logic, but why consider only one source in such a large region? And why consider a finite age in line the Huge Bang Fantasy? This structure is likely far older than convention allows. And it likely has many super-stars with active jets therein, maybe each a potential source of iron.
Ewan OSullivan
2.2 / 5 (10) Nov 19, 2013
Regarding the source of the gas motion, we require a lot of energy to move that much gas around. The only events likely to be that powerful are mergers or activity from a galaxy-central black hole. The radio data show us that only NGC 5044 has produced jets in the last few hundred million years, and that outburst doesn't seem to be a plausible cause of the gas motions. On the other hand, we see lots of evidence of merger or interaction-induced gas motions in galaxy clusters, and the structures we see here are exactly what we'd expect to see if this group has undergone such an interaction.

The ages involved are not dependent on a particular cosmology, they're estimated either from the sound speed in the hot gas, or the rate of radiative energy loss from the radio plasma.

As to "super-stars" with active jets, I'm not sure quite what you mean, but I see no evidence of other jets in any waveband at which the group has been observed.
cantdrive85
1 / 5 (13) Nov 19, 2013
cantdrive85: Perhaps you'd prefer to say it oscillates?


It has more to do with the clear misunderstanding of the behavior of plasma. Another example is the explanation of the twisted radio filament, such a morphology is ubiquitous in "magnetic ropes" or birkeland currents, no passing galaxy is needed.
Ewan OSullivan
2.8 / 5 (13) Nov 19, 2013
I'm not sure what properties of plasmas you think would prevent oscillation or sloshing. The magnetic field in the thermal plasma which is emitting the X-rays is small, of order ten micro Gauss, so the magnetic field certainly does not hold the plasma fixed in place. This material is sitting in the gravitational well of the group, with thermal pressure preventing it from collapsing inwards. If the gravitational potential changes, as it would if a massive galaxy falls through the group, the plasma will move in response to that change, and will then take some time to settle back into place. That's the sloshing we see, and this case looks very much like the simulations that have been done of that process.

As to the radio filament, it's morphology is very unusual for an AGN jet, and is closely correlated with the X-ray morphology, so you need an explanation which links the morphology of two very different plasmas - the sloshing explanation does that.
Ewan OSullivan
1 / 5 (8) Nov 19, 2013

Q-Star
3.3 / 5 (3) Nov 19, 2013
@ Ewan,

If it's really ya, welcome aboard. We can sure use ya around here, sorely.

The person ya are engaged with there is one of our EU plasma universe guys. Please never use the term hot gas in his presence, we'll never hear the end of it. Very entertaining fellow but tiresome after awhile.

The Tuxford fellow is an LaViolette, acolyte. Ya got two for one.
cantdrive85
1 / 5 (10) Nov 20, 2013
I get it, I'm well aware of the "standard" theory's POV in using kinetic gas laws to describe this plasma. Sadly, as has been shown for decades now, the foundation in which your "discoveries" are made is based upon faulty and just plain wrong models of astrophysical plasmas. You'd be doing yourself a favor by enlightening yourself in the plasma models proposed by Hannes Alfven et al., however enlightenment and job security don't necessarily walk hand in hand. This taken from Alfven's Nobel lecture;
"It (astrophysics) is to some extent the playground of theoreticians who have never seen a plasma in a laboratory. Many of them still believe in formulae which we know from laboratory experiments to be wrong."
Here, some 40+ years later astronomers such as yourself are still trying to describe this plasma as a gas. It's not even an apples and oranges comparison, it's more like apples and elephants.
http://www.nobelp...ture.pdf
GSwift7
not rated yet Nov 20, 2013
It should be noted that the distribution of iron and other gasses as shown in the image above isn't comprehensive. The streaks of iron you see in the image would be accompanied by other elements as well, but the specific frequency at which the image was taken is the frequency that the iron radiates most strongly at, while other elements in that same area just don't show up at that frequency range. The same goes for the other layers of the image; each layer is a specific frequency which highlights a specific type and temperature of material. The image does not show all the other types and temperatures of material there, since they radiate at frequencies that were not included. That ribbon of iron, for example, is surely just a trace element that happens to glow brightly at that specific frequency while the majority of material with it is hydrogen, helium, nitrogen and carbon.
yyz
5 / 5 (1) Nov 20, 2013
GSwift, as you noted, the image in this article shows the distribution of iron in the intercluster medium of the NGC 5044 Group (seen here in blue). Other studies using x-ray telescopes like Chandra, XMM-Newton and Suzaku have also studied the distribution and abundance of other metals (e.g. oxygen, neon, magnesium, silicon and sulfur) in the ICM of this galaxy group:

http://arxiv.org/.../0303054

http://arxiv.org/abs/1311.4636

These and other studies studies help astronomers understand how various mechanisms (e.g. supernovae, stellar winds) contribute to the enrichment of the intercluster medium in galaxy clusters and groups. The NGC 5044 Group in particular has been well studied due in part to its proximity to Earth.
GSwift7
not rated yet Nov 21, 2013
These and other studies studies help astronomers understand how various mechanisms (e.g. supernovae, stellar winds) contribute to the enrichment of the intercluster medium in galaxy clusters and groups


Yes, exactly, and with the Atacam array now fully operational, they will have the angular resolution to discerne a lot more about the smaller scale motions within the group, which will expose information about the distribution of unseen mass (dark matter). It is very fortunate to have so much visible gas amongst the galaxy cluster. It reveals forces and flow like we do with smoke trails in wind tunnels.
Fleetfoot
5 / 5 (1) Nov 23, 2013
Sadly, as has been shown for decades now, the foundation in which your "discoveries" are made is based upon faulty and just plain wrong models of astrophysical plasmas.


Clouds of plasma have the same mass and momentum as the same material in non-ionised form so the standard equations still apply to the cloud as a whole even where magnetic effects play a significant part within the cloud.

The two problems here are that you have no conception of the relative scales of the effects, imagining characteristics seen in toy "plasma globes" scale up without averaging, and you imagine plasma with no power source behaves the same as when a current is passed through it. You need to spend some time learning how real plasma behaves, not your Christmas toys.
cantdrive85
1 / 5 (8) Nov 23, 2013
Clouds of plasma have the same mass and momentum as the same material in non-ionised form so the standard equations still apply...

Thank you for continuing to show your absolute ignorance of the physics of plasma and the volumes of published material which shows your claims as being completely false. Where are all those magnetically confined fusion reactors your theory insists are possible? Somewhere with your DM and DE? Contrary to your outdated beliefs, electrical effects are ubiquitous is cosmical plasma. The real irony here is that PC and EU INCLUDES the obvious effects of gravity (albeit, in it's proper context), whereas the "standard" theory conveys magical properties to gravity while completely ignoring said electrical effects between particles.

You keep claiming there is no power source, yet all we see when we look up are plasma discharge phenomena. We see a filamentary and cellular universe, just as one who understands plasma would expect.
stellar-demolitionist
not rated yet Nov 25, 2013
Where are all those magnetically confined fusion reactors your theory insists are possible?


Theory doesn't "insist" that magnetically confined fusion can be easily achieved, only that if a plasma can be held in the appropriate state, fusion will occur. This is an experimentally verified fact. The troubles with practical fusion now are significantly a matter of controlling cooling losses and instabilities. These are both matters of engineering and the understanding of basic plasma instabilities.

BTW, I like the term "hot gas", especially if you insist on treating the the term "plasma" as if it implies behaviors induced by an external magnetic or electric field or an external current. Hot gas will do just nicely for a gravitationally confined, low density, hot (ionized) fluid without any significant external electromagnetic motive force.
Fleetfoot
5 / 5 (1) Dec 02, 2013
You keep claiming there is no power source, yet all we see when we look up are plasma discharge phenomena.


Nobody sees them but you. If you think there is a power source, say what it is. The fact is that the PC idiots have had this challenge hanging over them for decades and haven't a clue how to resolve it.

We see a filamentary and cellular universe, just as one who understands plasma would expect.


And just as anyone who understands Jeans Instability would expect too.
cantdrive85
1 / 5 (4) Dec 03, 2013
Nobody sees them but you. If you think there is a power source, say what it is.

You willfully ignore these obvious birkeland currents in favor of your own "magical" processes. The power source is inhomogeneous plasma and the movement thereof. The natural state of matter in the universe is plasma, this fact supported by simply looking up and recognizing that 99.99% of the universe is in this state. This process that you mistakenly identify as perpetual motion machine will continue as long as there is inhomogenuity in the makeup of the universe.