A super cluster of galaxies

Aug 28, 2012
A composite X-ray (purple), optical (red/green/blue), and UV (blue) image of the newly discovered Phoenix Cluster. This galaxy cluster has been dubbed the Phoenix Cluster because it is located in the constellation of the Phoenix, and because new stars are forming there at the highest rate ever observed in a cluster. Credit: X-ray: NASA/CXC/MIT/M.McDonald; UV: NASA/JPL-Caltech/M.McDonald; Optical: AURA/NOAO/CTIO/MIT/M.McDonald; Illustration: NASA/CXC/M.Weiss

(Phys.org)—Most galaxies lie in clusters, groupings of several to many thousands of galaxies. Our Milky Way galaxy itself is a member of the "Local Group," a band of about fifty galaxies whose other large member is the Andromeda Galaxy about 2.3 million light-years away. The closest large cluster of galaxies to us is the Virgo Cluster, with about 2000 members, whose center is about 50 million light-years away. The space between all these galaxies is not empty, but is filled with hot gas whose temperature is of order ten million kelvin, or even higher.

The development of clusters is a key feature of galaxy evolution, as hundreds or often thousands of galaxies are bound together by their mutual gravitational attractions. Clustering influences how a particular member galaxy will evolve, and reflects the larger cosmic structures and physical processes. Astronomers use observations of faint, distant galaxies to check for consistency in their models of , and to refine the parameters. The task of deciphering clustering in the is difficult, however, because distant galaxies are faint and only the brightest ones can be seen. Still, research to date has been very productive. Observations of galaxy clusters have recently shed important new light on everything from dark matter in the universe to early cosmological phases following the big bang.

Despite many successes, current models of galaxy clustering suffer from several glaring omissions. One relates to the fate of its hot, X-ray emitting gas. In the cores of clusters the gas is heated to by supernovae (the explosive deaths of stars) and other processes. The mystery is why this hot gas does not cool more efficiently and sink towards the center of the cluster. The common surmise has been that outflowing jets from , or other kinds of feedback, inhibit the formation of such "cooling flows," but establishing the details of this mechanism has been elusive.

CfA astronomers Ryan Foley, Matt Ashby, Bill Forman, Steve Murray, Brian Stalder, Tony Stark, Chris Stubbs, and Alex Vikhlinin are part of a team of astronomers who have discovered one of the largest and most luminous in the universe, the so-called Phoenix Cluster, about 5.7 billion light-years away. Using the Chandra X-Ray Observatory, the Magellan telescopes in Chile, the South Pole Telescope in Antarctica, and a suite of other space and ground-based facilities, the team finds that the cluster (at least currently) is undergoing a massive burst of star formation with about 740 solar-masses worth of new stars being created every year (for reference, the Milky Way forms about one star per year).

This was unexpected: most clusters support only modest star formation. At the same time, the team finds that the dominant black hole in the cluster does not show especially powerful jet activity. Writing in last week's issue of the journal Nature, the team concludes that this massive starburst is powered by the infalling material. They speculate that in this cluster the dominant black hole, although steadily growing in mass, has jets that are unable to halt the "cooling flow." The implication is that either this cluster is of a very rare kind, or that with subsequent evolution it will develop more effective and customary ways to inhibit the infalling material.

Explore further: Image: Chandra's view of the Tycho Supernova remnant

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cantdrive85
2.2 / 5 (13) Aug 28, 2012
First of all, that "gas" is not gas, it's plasma. And if it is emitting X-rays it is absolutely plasma, gas cannot emit X-rays any more than liquid can. Being that it is plasma, all their models and the claims they make will be wrong, the gas hydrodynamics to describe the "cooling flow" are totally inappropriate. Plasma does not behave like a gas and it is not at all a mystery as to why their models are inadequate. We live in a Plasma Universe, it's time for cosmology to set aside the assumptions of the 19th century and reconcile their assumptions with 21st century knowledge.
dtyarbrough
1 / 5 (11) Aug 28, 2012
Ten million degree gas heated by 6000 degree star surfaces. Makes perfect sense to these idiots. Just like the sun's corona. Xrays do not come from hot environments. They come from cool environments close to major disturbances, typically star remnants.
hemitite
not rated yet Aug 28, 2012
Perhaps they are supposing that cooling would lead to neutralization of this plasma, and thus its "cool flow" would be more in line with the ideal gas law.
antialias_physorg
4.4 / 5 (13) Aug 28, 2012
Ten million degree gas heated by 6000 degree star surfaces. Makes perfect sense to these idiots.

Yes it makes perfect sense because these guys know something about physics that you do not (basically all of it)

There are many other kinds of heating than simply transferring radiation energy. Here's 4 kinds which are used in tokamak setup to produce fusion on earth:
http://en.wikiped..._heating

The sun has high energy particles coming out. It also has intense magnetic fields. And 6000K is the AVERAGE SURFACE temperature. There's an entire energy and temperature distribution in the photons and solar wind particles coming from the sun - from infrared to gamma rays, from cool to extremely hot.

First of all, that "gas" is not gas, it's plasma. And if it is emitting X-rays it is absolutely plasma, gas cannot emit X-rays any more than liquid can

You can buy solid, liquid (and gas) X-Ray anodes. JFGI.
cantdrive85
1 / 5 (8) Aug 28, 2012
Perhaps they are supposing that cooling would lead to neutralization of this plasma, and thus its "cool flow" would be more in line with the ideal gas law.


That supposition is an incorrect assumption and would lead to even more incorrect conclusions.
dtyarbrough
1 / 5 (8) Aug 28, 2012
Imagine my surprise that you don't agree with me? But why do the magnetic lines heat the corona and cool the surface(sunspots)? Why doesn't the corona heat the sun's surface? Why don't we cook with ultraviolet instead of infrared if science is correct about energy levels of light?
cantdrive85
2.2 / 5 (13) Aug 28, 2012
There are many other kinds of heating than simply transferring radiation energy. Here's 4 kinds which are used in tokamak setup to produce fusion on earth:
http://en.wikiped...heating"

"You can buy solid, liquid (and gas) X-Ray anodes. JFGI.


Yep. And the common thread of those types of heating (and the Sun too)is electrified plasma, not gas.

Yes, but when you apply an electric current to a gas, solid, or liquid, it becomes a plasma. We all have a bit to learn about physics, don't you antialias!

Shinichi D_
5 / 5 (4) Aug 28, 2012

Why don't we cook with ultraviolet instead of infrared if science is correct about energy levels of light?


When cooking, we heat molecules, thats why longer wavelenghts are more effective. You sure noticed, how a microwave oven heats a cup of milk faster than a cup of water and both significantly faster than air.
Science is correct about the energy levels of light. It's been tested a thousand times.
dtyarbrough
1 / 5 (9) Aug 28, 2012
Why would long wave (low frequency) heat molecules better? Why not cook with radio waves? Microwave is the shortest of energy waves. Infrared if the most energetic of light photons(particles). Look at the absorbtion pattern of the earth's atmosphere. We're talking apples and oranges here.
antialias_physorg
4.3 / 5 (12) Aug 28, 2012
Why would long wave (low frequency) heat molecules better?

Because molecules (in the case of microwave ovens: water) warm when hit with their resonant frequencies. For water that happens to be around 2.5 GHz (which is actually a wavelength in the millimeter and not the micrometer range).

If you hit something with x-rays then it just gets ionized (and only some secondary effects cause heating). So using X-rays is very wasteful in terms of heating (also xrays are a lot harder to produce than microwaves)

And the common thread of those types of heating (and the Sun too)is electrified plasma, not gas.

No. Some material will be render gaseous as a byproduct, but the effect that creates the X-rays is Bremsstrahlung - not plasma.

We all have a bit to learn about physics

You certainly do. You're absolutely right, there.
daywalk3r
2.5 / 5 (8) Aug 28, 2012
There's an entire energy and temperature distribution in the photons and SOLAR WIND PARTICLES coming from the sun

Just curious, how do you define the temperature of a single isolated proton in vacuum? ;o)

(Yes, it is a catch question.. lol)
cantdrive85
1 / 5 (8) Aug 28, 2012
No. Some material will be render gaseous as a byproduct, but the effect that creates the X-rays is Bremsstrahlung - not plasma.

You certainly do. You're absolutely right, there.


This from wikipedia,
Bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus.

According to the definition, a plasma (charged particle) interacting with another plasma (charged particle) creates the radiation. I don't see where I'm incorrect in saying the common thread is plasma, you do understand that a charged particle or ionized particle are considered plasma, right?
Q-Star
3.8 / 5 (10) Aug 28, 2012
Why would long wave (low frequency) heat molecules better? Why not cook with radio waves? Microwave is the shortest of energy waves. Infrared if the most energetic of light photons(particles). Look at the absorbtion pattern of the earth's atmosphere. We're talking apples and oranges here.


Apples and oranges? No we're talking physics here. Not some drug induced ponderings. Where do you get these strange ideas? This is a science forum, not a science fiction test platform. It's really inappropriate to try out new material in a forum where some sincere but uninformed person might come seeking knowledge.

"Microwave is the shortest of energy waves."???? Not in this universe. (Maybe in one that is in a poor work of fiction.)

"Infrared if the most energetic of light photons(particles)."????? Again, NOT in this universe. In this universe, infrared is in the mediocre range.
dtyarbrough
1 / 5 (11) Aug 28, 2012
Ten million degree hot gas between the galaxies. You call that knowledge? I call that insanity. All because they see xrays. Xrays have been created in a vacuum by peeling scotch tape from a roll. My guess is there isn't any scotch tape out there or hot gas either.
lengould100
not rated yet Aug 29, 2012
from the article -
the team finds that the dominant black hole in the cluster does not show especially powerful jet activity.
That's news to me. Has anyone else ever heard that galaxy clusters may have dominant black holes? Are they simply assigning a label to eg. the largest black hole at the centre of any galaxy in the cluster?
lengould100
not rated yet Aug 29, 2012
BBC website does a decent job, claiming just what I speculated above, that the cluster's largest and / or most central galaxy is assigned as "dominant".

http://www.bbc.co...19266284

Another relevant article here, again BBC website.

http://news.bbc.c...0038.stm
antialias_physorg
5 / 5 (5) Aug 29, 2012
According to the definition, a plasma (charged particle) interacting with another plasma (charged particle) creates the radiation. I don't see where I'm incorrect in saying the common thread is plasma,

Because a plasma is a partially or fully ionized form of GAS, The atoms which are the targets of the electrons from the cathode in X-ray tubes are SOLID (or liquid forms). They are - not even by the most twisted definition - a plasma.
cantdrive85
1.1 / 5 (9) Aug 30, 2012
According to the definition, a plasma (charged particle) interacting with another plasma (charged particle) creates the radiation. I don't see where I'm incorrect in saying the common thread is plasma,

Because a plasma is a partially or fully ionized form of GAS, The atoms which are the targets of the electrons from the cathode in X-ray tubes are SOLID (or liquid forms). They are - not even by the most twisted definition - a plasma.

Clearly you have zero understanding of plasma, plasma is a DISTINCT STATE OF MATTER, it is not gas! Solid, liquid, gas, and plasma, I know your high school science books taught only three, but there are in fact four states of matter, and plasma just happens to be over 99% of the Universe. Also, any state of matter can quickly become a plasma if an electric current is induced upon it, for example, the copper wire (hot) your computer is plugged into is in the plasma state. Inform yourself before you make a further fool of yourself.
antialias_physorg
5 / 5 (5) Aug 30, 2012
Clearly you have zero understanding of plasma, plasma is a DISTINCT STATE OF MATTER, it is not gas!

It's what you get when oyu ionize a gas (yes, it's a fourth state). Thats the definition everybody uses. If you want to talk about different things then don't use the word plasma.

A plasma is ((partially)ionized) atoms in an UNBOUNDED state. A copper wire - even while conducting electricity - is not a plasma in any way, shape or form.
Every definition I just looked up speaks of a partially or fully ionized GAS as a plasma.

The idea solids with mobile electrons in bands is a 'plasma' exists only in your head. Because if that would fit then there would never be any solids (or liquids, or gases). By your definition there would be only one state of matter, because in ALL states you occasionally have exchanges of electrons where individual atoms are - for that moment - 'ionized'.
Q-Star
2 / 5 (4) Aug 30, 2012
Ten million degree hot gas between the galaxies. You call that knowledge? I call that insanity. All because they see xrays.


The reason you would call that insanity is because you don't realize that in physics temperature is a quality that is not the same as a layman's idea of hot oatmeal and cold ice cream. Temperature is a measure of the energy of a thing. How much it is jiggling. You could survive quite happily in a temperature of 5,000 K. AS LONG AS IT WAS A VERY DIFFUSE MEDIUM. 10 particles at 5,000 K wouldn't be nearly as "HOT" (in layman's terms) as 1000 particles at, say, 273 K.

Maybe you confuse temperature in physics with heat in the kitchen. Temperature is a physical property. Heat is an entirely subjective word and has no quantity.

One day you should actually read an introductory physics text, just trying to parrot the captions under the pictures doesn't count.
Fleetfoot
not rated yet Sep 01, 2012
Why don't we cook with ultraviolet instead of infrared if science is correct about energy levels of light?


Several reasons, ultraviolet would not penetrate the surface, it would scorch things but leave them raw inside. As has been said, microwave cookers work at a frequency which corresponds to a resonance in water and some other molecules but food is mostly transparent so the heating is relatively uniform.

Why not cook with radio waves?


Mainly because the wavelength has to be less than the size of the cooker cavity but also because magnetrons are relatively inexpensive and robust, they do not rely on active (semiconductor) devices:

http://en.wikiped...agnetron
Fleetfoot
not rated yet Sep 03, 2012
Temperature is a measure of the energy of a thing. How much it is jiggling. You could survive quite happily in a temperature of 5,000 K. AS LONG AS IT WAS A VERY DIFFUSE MEDIUM. 10 particles at 5,000 K wouldn't be nearly as "HOT" (in layman's terms) as 1000 particles at, say, 273 K.

Maybe you confuse temperature in physics with heat in the kitchen. Temperature is a physical property. Heat is an entirely subjective word and has no quantity.


I think that may be a typo, "hot" is a subjective word but "heat" is a measure of thermal energy, typically quantified in Joules.