The Coma Galaxy cluster is home to a rich collection of galaxies in the nearby Universe. NGC 4921 is one of the rare spirals in Coma, and a rather unusual one. It looks “fluffy,” with lots of swirling dust. Astronomers say this galaxy is an “anemic spiral” where a small amount of star formation is taking place, and so less light is coming from the galaxy’s arms, as is usually seen in a spiral galaxy. This is an image from the Hubble Space Telescope, and with Hubble’s sharp vision, you can see a few bright young blue stars. But what’s really amazing, besides seeing the incredible detail of NGC 4921, is looking beyond the big fluffy galaxy and seeing how Hubble was able to pick up a marvelous collection of remote galaxies of all shapes, sizes and colors. Many have the spotty and ragged appearance of galaxies from the early Universe. Click here to get a bigger, better view.
This image was created from data obtained by Hubble’s Advanced Camera for Surveys. The Coma galaxy cluster, is in the northern constellation of Coma Berenices. The cluster, also known as Abell 1656, is about 320 million light-years from Earth and contains more than 1000 members. The brightest galaxies, including NGC 4921, were discovered back in the late 18th century by William Herschel.
The galaxies in rich clusters undergo many interactions and mergers that tend to gradually turn gas-rich spirals into elliptical systems without much active star formation. As a result, there are far more ellipticals and fewer spirals in the Coma Cluster than are found in quieter corners of the Universe.
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The Hubble images used to make this picture were originally obtained by a team led by Kem Cook (Lawrence Livermore National Laboratory, California). The team used Hubble to search for Cepheid variable stars in NGC 4921 that could be used to measure the distance to the Coma cluster and hence the expansion rate of the Universe.
Unfortunately the failure of the Advanced Camera for Surveys in early 2007 meant that they had insufficient data to complete their original program, although they hope to continue after the servicing mission. Very deep imaging data like this, which is available to anyone from the Hubble archives, may also be used for other interesting scientific exploration of this galaxy and its surroundings.
The top image was created from 50 separate exposures with a yellow filter and another 30 exposures with a near-infrared filter using the Wide Field Channel of the Advanced Camera for Surveys on Hubble. The total exposure times were approximately 17 hours and 10 hours respectively.
38 Replies to “Deep Hubble View of Unusual “Fluffy” Galaxy – and Beyond”
I already made it my new desktop for the week! =-)
I’d be curious how this would look with Spitzer and/or Chandra. Since it is “anemic” WRT star formation I’d expect to see a huge black hole signature via Chandra if current theories of black holes and how they regulate star formation is true.
The dark areas between the arms probably don’t have a lot of dust (not much to see w/ Spitzer) because you can see background galaxies through them.
What a great time to be in Astronomy!!! =-)
This is truly spectacular!
Imagine all the life out there.
Salacious B. Crumb Says:
February 5th, 2009 at 8:32 am e
Holy Toledo, boy there is a awful lot of galaxies in this image… NGC 4921 certainly is fluffy galaxy wrapped in cotton wool – and is real terms is 77 Mpc (251 million light-years) from us. Also the zoomed image reveals near the centre a close near equally bright yellow double star from own galaxy. Just breathtaking.
NASA Extragalactic Database notes on NGC 4921 says; “This is the other giant spiral in Coma, also projected close to the cluster center, at 25′ southeast (~0.5 Mpc). … it is very high H I deficiency… [and] It shows a very perturbed gas distribution, which is clearly less extended than the optical disk. Most of the H I emission is distributed along the southeast spiral arm, while the northwest appears depleted. The H I centroid exhibits a slight offset, 10″ east of the optical centre.”
“In NGC 4921 only little X-ray emission was detected. This emission is not concentrated at the centre of the galaxy (as would be usual for an E or S0 type system), but it is rather diffuse, with several weak emission maxima. This shallow emission distribution of NGC 4921 indicates that there is no pronounced central concentration of X-ray emitting gas, implying the absence of a cooling flow”
This probably accounts for the odd fluffiness. Clearly it is unlike our own Milky Way.
Certainly an inspiring image that could be inspected for hours – but don’t make it a jigsaw puzzle please…
“I’d expect to see a huge black hole signature via Chandra if current theories of black holes and how they regulate star formation is true.”
Sadly this is probably unlikely as the central region shows no real activity central concentration in the X-ray. I’d say this might be unlikely in this galaxy, but there are other candidates in the Coma Galaxy cluster that would be worth checking out.
1. How come there is no so-called “gravitational lensing” of the remote background galaxies in that photograph?
2. How come the alleged blackhole at the center of NGC 4921 doesn’t suck in the light of the background objects with it’s overwhelming “gravitational” force?
Hubble does it again – that is absolutely stunning! I could spend all week just looking at it.
RapidEye – you’re right. We are so lucky to be here now, when there’s so much happening and so many new things to see.
Go Hubble! After her upgrade who knows what she will show us? Watch this space!
incredible!!! I was going to crop the pic to fit the resolution of my 30″ FP, 2560×1600, but, I will lose the full perspective- so I said forget that and will hunt for the tiff image of this incredible image- so what if it requires 25-30mb of space, I can also look for hours and vegetate looking at this incredible picture lol.
Thank you for posting this picture!!!
Can a grown man cry !?! Looking at this (magnified image) brought tears to my eyes. I can not believe the number of galaxies and space objects in this beautiful and captivating shot from Hubble. It stirs my soul! Ros den herskende Guden av universet for evig og noensinne! Flipping awesome!
# OilIsMastery Says:
February 5th, 2009 at 1:30 pm
1. How come there is no so-called “gravitational lensing” of the remote background galaxies in that photograph?
2. How come the alleged blackhole at the center of NGC 4921 doesn’t suck in the light of the background objects with it’s overwhelming “gravitational” force?
1) Look up ‘weak gravitational lensing’. Warped images, arcs and rings etc. are all firmly products of the ‘strong lensing’ regime. Strong lensing requires a VERY specific geometric relationship between viewer, lensing object and background object. Even then effects can be small unless the galaxy cluster is particularly massive. Also, it really doesn’t happen unless both source and lens are very distant – a fair bit more distant than this galaxy.
Weak lensing is far more subtle, and is really only detectable with a huge amount of statistical analysis using many background objects. Work such as this may be happening for this image right now – who knows? So, this is all what General Relativity predicts anyway. Everything is as expected.
2) Why would the black hole ‘suck in the light’ from the background objects? A supermassive black hole, even some of the largest, have a Schwarzchild Radius measured in tens of millions of km. That may sound a lot, but it’s only a couple of light minutes at best. So, give or take, it is about 1/ 45 billionth of the diameter of the galaxy. The original image is 3840 pixels wide, so that means that the black hole would occupy a width on the image of about 1/12 millionth of a screen pixel. Light is only sucked into a black hole if it travels on a trajectory directly into it, or starts out already inside the event horizon – i.e. the only light we would see sucked in is that which comes from directly behind it from our point of view. So, since a pixel is 2-dimensional, to get the total amount of light lost in terms of pixel area due to the black hole we take 1/(12000000^2). So a grand total of 1/144 trillionth of a pixel’s worth of light would be lost to our telescopes at this image resolution due to direct blocking by the black hole.
Light that does not venture within the event horizon merely has it’s trajectory altered – significantly for light grazing near to the hole, but decreasing rapidly as we move further away (as the square of the distance). Now, running some (very quick and dirty) calculations with simple Newtonian gravity (fine to do in the weak field scenario we are considering), the gravity felt from the black hole would be about the same as that at the surface of the sun only about 20 light-days away from it, and the deflection of light for such a weak field is minimal to say the best – note the painstaking work required to measure the minute gravitational deflection of light by the Sun. 20 light days is still only about 1/500th of a pixel-width on the full sized image, and so there would be absolutely no visible effects in a simple colour image such as this due to the black hole. Spectroscopy however, tells us a lot more. But that is different matter entirely and another story altogether.
Again though, everything is as expected. Gravity triumphs! Hazaaa!
“…merely has it’s trajectory altered – significantly for light grazing near to the hole, but decreasing rapidly as we move further away (as the square of the distance).”
Should read more like “has its trajectory altered, in proportion to the strength of the gravitational well it travels through, which in the Newtonian limit goes as the inverse of the square of the distance from the hole.”
Also note – many of the quick and dirty calculations were based on the mass of Sgr A*. This is not a huge black hole by cosmic standards, but the points illustrated remain valid.
Astrofriend-extremely well said and very understandable. It is incredible about the detail of this galaxy 320M LY away,
Even thought I am somewhat of a computer geek like others I know on the net, the area of a pixel you mentioned verifies the enormous
distance and what would appear to humans sense to be large entities and distances of 20 L-days, makes very clear how insigniicant 20 L-days is compared to the size of NGC 4921. Now what I hope for is to find or have NASA, ESA and K. Cook (Lawrence Livermore National Laboratory) release a TIFF image.lol
You say, “Strong lensing requires a VERY specific geometric relationship between viewer, lensing object and background object.”
Since you are the resident expert on gravitational lenses, perhaps you can tell us what “specific geometric relationship” you refering to. What are the geometric requirements for a gravitational lens to occur?
You say, “it really doesn’t happen unless both source and lens are very distant – a fair bit more distant than this galaxy.”
What distance does an object need to be from the Earth in order for a gravitational lens to occur?
You ask, “Why would the black hole ‘suck in the light’ from the background objects?”
Great question. Since black holes don’t exist, gravity doesn’t exist, and photons are alleged to have no mass, I don’t have an answer.
What is the mathematical relationship between mass, distance, and gravity? Why don’t so-called black holes exert gravitational force beyond the alleged Schwarzschild radius and event horizon? Why does gravity break down? At what distance from a massive object does gravity break down and what is the mathematical ratio of mass to distance in order to determine it?
You say, “many of the quick and dirty calculations were based on the mass of Sgr A*.”
What is the mass of Sagittarius A*? Why do stars orbit Sagittarius A* instead of falling on it by it’s gravity? At what distance from Sagittarius A* does gravity break down?
Bloody great picture!! Cool!!!!
What is the object about 10% of image height below the upper right corner, looks like a globular cluster?
Looks like a proto-galaxy in the process of acreting material. Give it a few more billion years.
What is more impressive in the image are the myriad
galaxies in the bg. Are we alone?
Not a chance.
It’s the Omega Point!
I dont think there is any point arguing with Oilsmastery, or trying to explain anything. Let him write his sarchastic comments and leave it at that, after awhile he will go away, starved from any attention – children behave like that.
At least children know how to spell sarcastic.
Isn’t the word meaning “sarchastic” is even more ironic? Perhaps “sarcastique” is even better! Moi oui?
These images are simply spectacular and humbling; kinda puts things into perspective don’t it?
Q. why are the distant/young/early universe bg galaxies, esp. the circled/captioned ones, not “all” showing a strongly red shifted spectral signature? Some are red, some are white and some are blue. I asked this before when the famous HST deep field image was published 3 or 4 years back and didn’t get an answer.
Maybe these HST images are composites taken with multiple filters and we’re seeing different chemical signatures?
Oills, I’m by no means an expert on gravitational lensing, and never claimed to be. But I am a physicist and I know enough. I’d address the points in your post, but I honestly just don’t have the time, patience, energy or frankly the desire at this time of night.
You have, in your previous post, demonstated such an astounding lack of understanding about even the most basic properties of gravity (amazing even considering you don’t believe in it), that talking about gravitational lensing with you would be like chatting to your average 8 year old about methods that can be used to solve non-linear partial differential equations. They would simply not have the prerequisite knowledge to even begin to discuss math at that level. It’s the same situation here I’m afraid mate. Read up, if only so you can pose questions that actually make sense…
That’s the most persuasive, empirical, and scientific observation and evidence for the actual existence of a gravitational lens I’ve ever seen.
Read up on this: gravity is a myth.
“…to establish it [gravity] as original or primitive in certain parts of matter is to resort either to miracle or an imaginary occult quality.” — Gottfreid W. Leibniz, polymath, July 1710
“Thus, thinking as Newton did (i.e., that all celestial bodies are attracted to the sun and move through empty space), it is extremely improbable that the six planets would move as they do.” — Pierre L. Maupertuis, mathematician, 1746
“What we call mass would seem to be nothing but an appearance, and all inertia to be of electromagnetic origin.” — Henri Poincaré, physicist, 1908
“Gravitation is an electromagnetic phenomenon.” — Immanuel Velikovsky, cosmologist, 1946
“An atom differs from the solar system by the fact that it is not gravitation that makes the electrons go round the nucleus, but electricity.” — Bertrand Russell, physicist/philosopher, 1924
“All planets revolve in approximately one plane. They revolve in a plane perpendicular to the lines of force of the sun’s magnetic field.” — Immanuel Velikovsky, cosmologist, 1946
OillsMastery-I’ve read reports starting about 1978 that the Earth has an incredible amount of petroleum,perhaps 20k generations as comets are much hydrocarbons, it is merely economics that is the driving force for exploration and production. I also did not subscribe to the ‘end of the world ‘mainstream” media we are running out of petroleum . When the price of extracting the ‘easy oil’ and prices rise, technology not now available or feasible will eventually get to the true ‘monster pools’ of hydrocarbons in our Earth. I just wanted the use of petroleum to lessen as it does lessens the ability to see the night skies -I do no believe the BS about humans being the complete cause of ‘global warming’ as on other feeds, I stated the Sun is 98% cause of our climate, the Earth itself is about 2%, humans as a fraction of .1%. These so calle ‘Global Warming’ advocates wants to create a breaucracy which calls for more funds, funds equals power, power demands more funds which equals more power. As other sources of energy is still in the teething stage or will be found unfeasible (full battery operated vehicles-where is the energy going to come from to power these things and the recycling of batterys is a losing proposition regardless of advanced technology and they are toxic!! ), fusion power is going to be in a state of research for a long time, solar energy to power a large metro area will require thousands of square miles of solar cells, wind power-NIMBY thinking and they will eventually corrode in the elements, fuel cells may be part of the solution in 50 years but there may be problems in collisions but may be the feasible powered vehicles after having
to creat a infrastructure of power plants, network of ‘service station’ for fuel cells(I try to remind people how long it took to creat a network of ‘service stations’ in the US). Nuclear Power Plants,-where is all the spent cells going to go to-besides- there is a NIMBY mentality in the US. Natural Gas, production will have to iincrease incredibly and it does have its’ dangers, but may also power vehicles. Economics of scale will eventually find enormous amount of vast cavities of Natural Gas when the ‘easy sources’ are used up. Petroluem will continue to be the choice of power for the rest of the century.
I then clicked on your ‘nickname’ because it appears to be hyperlinked, low and behold,
you also have a lot of research and also believed about the amount of hydrocarbons in the Earth and the BS the ‘mainstream’ media and so call ‘end of the world expert’ on running out of petroleum and BS on many other subject matters. I’ve learned alot about comets because IMHO, it is completely correct. However, there are a few things I can not comprehend or believe on your website, however, the US is a ‘free’ country and the world does need people like you as a counter to open up thinking on how our Earth and the Universe does operate.
I now respect you although I do have reservations on some of your sources for your
hypothesis of our Universe. Take care
Thank you for your input and your kind words.
“Sounds crazy, I know, but then so did the idea of sending a man to the Moon when it was first proposed. Good scientists just follow the physics, and that’s all we’re doing here. Everyone else will catch up at their own pace.” — Charles Chandler, natural philosopher, October 2008
I’d read up on it Oills, but I can’t seem to find any papers or books written by anyone that aren’t either anonymous cranks on the internet or yea-olde scientists from centuries long past who didn’t have the empirical data that we know have at hand to work with or consider. Is that your whole armory Oills? Quote either a discredited fringe ‘scientist’ like Velikovsky, or the words of some ancient philosopher who lived before the word ‘science’ or the concept of experimental verification of ideas had even come into existence? I’ll say it again then – appeals to authority (quoting somebody famous) does not equal evidence. It does not make your theory true. It doesn’t make it wrong either. It does nothing at all!
Anyway, I have read some of Velikovsky’s stuff – Cosmos Without Gravitation for one. Despite it being rather creative, there is not one solid quantitative prediction that can be measured in there. And since that time, even despite the vagueness bordering on astrology, almost every word has been shown to be wrong with modern space probes etc. etc. I don’t deny that anyone has the right to present a new theory or world view, but science insists that they be subject to the ultimate arbiter – actual physical evidence. And Velikovsky has failed that test admirably.
P.S – as a fitting example of your misquotes – quoting Bertrand Russell to try to disprove gravity? Good one buddy – he actually wrote quite an authoritative introduction to General Relativity, used by students the world over. Moreover, he simply states in the quote you attributed to him that (to paraphrase) ‘an atom is like a miniature solar system but the force that holds them together is different – i.e. electromagnetism and gravity’. Of course it is – gravity and electromagnetism are both inverse square laws, so of course they’ll behave the same in that sense. What’s more – this quote was from the early twenties before Quantum Mechanics had been developed – nobody had an even close understanding of the true nature of an atom yet. Later in his life, Russell would go on to consider QM and write excellent material in relation to it, too.
Have a super-charged day Oills.
You say Velikovsky is a “discredited fringe scientist” but I submit to you that it is Newton and Einstein who have been discredited and they aren’t even scientists.
You accuse me of quoting the words of ancient philosophers yet you believe in a 17th century creationist hypothesis of universal gravitation that was empirically falsified in 1963, not to mention 1687.
Your claim that “almost every word has been shown to be wrong with modern spaceprobes” is simply based upon illiteracy, ignorance, and a lack of education.
“I interviewed him [Velikovsky] several times at his home, and remain convinced that although he is most likely wrong on specifics, he will be remembered by history as a genius and pioneer.” — Clark Whelton, historian, December 2008
“These researchers have demonstrated certain inescapable conclusions. They have shown that Velikovsky was wrong on numerous specifics. But on several of his most fundamental claims, all of the evidence accumulated by historical investigation and by space age exploration lines up in Velikvosky’s favor. This is the fact that the zealots for ‘consensus’ science do not want you to know.” — Michael Goodspeed, journalist, October 2008
“Seeds of active interest are now present within most of the major divisions of NASA, in plasma science laboratories, and in numerous universities. Many have never read Velikovsky, nor even heard his name in some instances. Some would prefer that Velikovsky never be mentioned, due to the public relations success of Velikovsky’s critics in the mid-seventies. In numerous ways the present movement has left the Velikovsky question behind — though it would be senseless to imagine that the truth about the Velikovsky controversy could remain hidden forever. ” — Michael Goodspeed, journalist, October 2008
“Some ‘scientists’ attempted to suppress Velikovsky’s ideas. The supression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge and there’s no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system and the history of our study of the solar sytem shows clearly that accepted and conventional ideas are often wrong and that fundamental insights can arise from the most unexpected sources.” — Carl Sagan, cosmologist, 1980
” Torquemada was evil; Velikovsky’s academic enemies, merely foolish.” — Stephen Jay Gould, biologist, 1977
“Our debate ended on Friday, April 8, 1955, only nine days before Einstein’s death. I think I was the last person with whom he discussed a scientific problem. On that day I brought him the published news that Jupiter sends out radio noises; ten months earlier, in a letter to him, I had offered to stake our dispute on this my claim of an as yet undiscovered phenomenon…” — Immanuel Velikovsky, cosmologist, 1976
“But then if there were events of this character, discharges between planets and so on, I put one of the most outrageous claims before the scientific readers, that in the solar system and in the universe generally, not just gravitation and inertia are the two forces of action but that also electricity and magnetism are participating in the mechanism, so the Lord was not just a watchmaker. The universe is not free of those forces with which the man makes his life easy already more than 100 years. They were unknown practically or little known in the time of Newton in the second half of the 17th century. But today we know that electricity and magnetism, these are not just small phenomena that we can repeat as a kind of a little trick in the lab, that they permeate every field from neurology into botony and chemistry and astronomy should not be free…and it was admitted by authorities that this was the most outrageous point in my claims. But the vengeance came early and swiftly. In 1960, already in 1955, radio noises from Jupiter were detected and this was one of the crucial tests that I offered for the truth of my theory. In 1958, the magnetosphere was discovered around the Earth, another claim. In 1960, the interplanetary magnetic field was discovered and solar plasma, so-called solar wind, moving rapidly along the magnetic lines and then it was discovered that the electromagnetic field of the Earth reaches the moon .” — Immanuel Velikovsky, cosmologist, 1966
“Some of these predictions were said to be impossible when you [Velikovsky] made them. All of them were predicted long before proof that they were correct came to hand….” — Harry Hess, geologist, 1963
“Velikovsky’s credentials were not those of a scientist…he had only the vaguest understanding of such basic physical principles as conservation of angular momentum, gravity, and entropy.” – Lloyd Motz, (whose advice Velikovsky often sought)
“Velikovsky was an interesting and imaginative thinker, and he was a patient, thorough collector of ancient myths and legends. But his work, whatever other virtues it may possess, is not science” – Gregory Derry
“Saying that there will be found radio emissions from Jupiter was tantamount to a statement by John Adams in mid-19th century that there was another planet in the sky but with no more evidence, say, than the peculiarities of Uranus’ motion…. Velikovsky’s prediction was precisely useless in just its LACK of detail– where to look in the radio spectrum (from ground base it covers a factor of 10,000 to one in frequency); what to see there, that is the character of the source (Velikovsky didn’t understand that two kinds of distinct non-thermal emission are produced); and when to look (Burke’s and Franklin’s data show enormous variations that seemed to be basically stochastic)” – radio-astronomer James W. Warwick
I’d find more, but it’s really boring.
Amazing, i am still in awe when i see these galaxy pictures with all the other galaxies in them… breath taking.
So do you think Venus is Earth’s sister planet with oceans and an atmosphere at room temperature?
Do you think there is no sound in space?
Do you disbelieve the Earth’s magnetic field?
Oills – why are you asking me these questions? Why would I believe that Venus is like that when it has been shown that it is not by a veritable armada of various spacecraft? Why would I not ‘disbelieve’ the Earth’s magnetic field? Why do you ‘disbelieve’ the Earth’s gravitational field?
And sound in space?? There is no sound in space from the point of view that if we were in space together and I banged a drum, you wouldn’t hear it. There is a highly rarefied gas in space that can transmit shock waves however – MHD waves, which are a well-understood aspect of plasma physics.
If you are asking about these things because they form a part of Velikovsky’s claims, then I say that it has nothing to do with anything. Velikovsky has been right about certain things, but these are always played up by his true believer cheer squad as being major triumphs. In fact, almost all the stuff he was actually right about he fluked – he was right but not for the reasons that he posited. For example, he claimed Venus was shot out of Jupiter, and this is responsible for it’s current day temperature. But the weather systems have been particularly well studied on Venus, especially since Venus Express arrived on the scene. And the mechanisms for Venus’ current temperature are thoroughly certified as being due to proximity to the sun combined with a thick atmosphere comprised largely of CO2.
He claimed that Jupiter would have radio emission due to turbulence from the expulsion of Venus. Jupiter does have radio emission, but completely lacking the characteristics predicted by Velikovsky – Jupiter’s radio emission is from a combination of factors, but particularly from synchrotron radiation etc which are unexplainable by his model.
There is no denying Velikovsky was a deep and creative thinker. He just happened to be wrong on pretty much all counts. Science is a bitch like that eh? Reality doesn’t care how clever your idea is.
1 – Download this picture and stretch across two monitors and enjoy it in all its glory and detail
2- Oils mastery, I’m intrigued by a few of the websites that you have posted on your alternate theory to gravity and the likes. Would you be so kind ( in all seriousness) to just some up the work in a few short lines.
I’m studying for midterms currently so I don’t have time to read the whole web page but a quick re-cap would be appreciated.
Bojan, I’ve already stretch to 2 FP-a 30″ and/or 26″24″, but I wish they make available a TIFF image of NGC 4921 ,I checked thru the ‘net, still can’t find. So what if it’s probably 25-35mb, it will be an even more awesome picture in greater detail!
Down low on the comments list I read the phrase “discredited fringe scientist:” i.e. Immanuel Velikovsky/ You ought to read “The Age of Velikovsky” by Ransom, I think, then read “Earth In Upheaval” by Velikovsky and you start to get an idea of a nest of nattering nabobs of negativity nuts who are really churlish in trying to downplay Velikovsky.
Viva Velikovsky who said “Ridicule is the argument of the mob”. We are resting assured that the scientific “laws” have to conform to facts. (Then you have the sad sack who maintainens that it is “proven” that Venus is hot bercause of proximity tyo the sun and the greenhouse effect.
Young people, question authority, as Socrates implored!
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