Hubble image: Don't trust your eyes

Dec 31, 2012
Credit: ESA/Hubble & NASA

(Phys.org)—The Universe loves to fool our eyes, giving the impression that celestial objects are located at the same distance from Earth. A good example can be seen in this spectacular image produced by the NASA/ESA Hubble Space Telescope. The galaxies NGC 5011B and NGC 5011C are imaged against a starry background.

Located in the constellation of Centaurus, the nature of these galaxies has puzzled astronomers. NGC 5011B (on the right) is a belonging to the Centaurus lying 156 million light-years away from the Earth. Long considered part of the faraway cluster of galaxies as well, NGC 5011C (the bluish galaxy at the centre of the image) is a peculiar object, with the faintness typical of a nearby dwarf galaxy, alongside the size of an early-type spiral.

Astronomers were curious about the appearance of NGC 5011C. If the two galaxies were at roughly the same distance from Earth, they would expect the pair to show signs of interactions between them. However, there was no visual sign of interaction between the two. How could this be possible?

To solve this problem, astronomers studied the velocity at which these galaxies are receding from the Milky Way and found that NGC 5011C is moving away far more slowly than its apparent neighbour, and its motion is more consistent with that of the nearby Centaurus A group at a distance of 13 million light-years. Thus, NGC 5011C, with only about ten million times the mass of the Sun in its stars, must indeed be a nearby dwarf galaxy rather than member of the distant Centaurus Cluster as was believed for many years.

Problem solved.

This image was taken with Hubble's for Surveys using visual and infrared filters.

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btb101
5 / 5 (9) Dec 31, 2012
Once again the old lady of the skies has shown to effective in solving a conundrum. She might be ageing and past her 'sell by date' but time and again she has proven her worth.

This is one piece of NASA that should not be allowed to fall back to earth in a fiery death. she should be kept on. NASA should make it a priority to keep her flying. Images such as these and the information being provided should be continued for many more decades to come.

JRi
4.3 / 5 (7) Dec 31, 2012
From the image above, it is obvious that NGC 5011C is closer since you can see the individual stars, while NGC 5011B shows only a white cloud of "stardust" with no detail.
megmaltese
2.3 / 5 (9) Dec 31, 2012
It looked to me so obvious that the 'bluish galaxy' is much nearer to Earth than the one on the right simply because I can see granularity in it, while the other one is much more blurred.
Lurker2358
2 / 5 (7) Dec 31, 2012
It looked to me so obvious that the 'bluish galaxy' is much nearer to Earth than the one on the right simply because I can see granularity in it, while the other one is much more blurred.


The one on the right is much brighter, but the one on the left looks like a globular cluster.
ValeriaT
2.9 / 5 (9) Dec 31, 2012
The difference in size of stars inside of both objects is quite apparent even at the older pictures of 3.6 m ESO telescope at La Silla - so I don't understand, why 1) it's presented like the success of Hubble 2) it's presented like some phenomenal finding. Even laymans here are able to recognize this apparent difference. So I conclude instead, whole article lacks context, being sensationalist and karma whoring.
trapezoid
4.3 / 5 (6) Dec 31, 2012
imaged against a starry background.

You mean stars against a background of galaxies
ValeriaT
1.9 / 5 (17) Dec 31, 2012
Why We Have So Much "Duh" Science. Someone should check, if the money of tax payers were really invested into serious research in this particular case and people responsible punished for it. The contemporary science completely lacks the public feedback and scientists itself aren't willing to control to check their own spending. In Czech we have a proverb: "The carps never empty their own pond".
Lurker2358
1.5 / 5 (17) Dec 31, 2012
http://science.slashdot.org/story/11/06/01/1937220/why-we-have-so-much-duh-science. Someone should check, if the money of tax payers were really invested into serious research in this particular case and people responsible punished for it.


Most of existing astronomy isn't serious research.

They are basically permanent government or university salary photographers.
dbren
5 / 5 (7) Dec 31, 2012
Shouldn't the photo caption say that the galaxies are imaged behind a starry foreground?
bliskater
1.8 / 5 (5) Dec 31, 2012
seem's to be much (as stated) "duh-hing". I'd rather just ask why was the apparently obvious not so apparent to those who truly are better at this stuff than us laymen?
My first assumption is that there are far more pictures than scientists to analyze them. ??????
cantdrive85
1.3 / 5 (13) Dec 31, 2012
If the two galaxies were at roughly the same distance from Earth, they would expect the pair to show signs of interactions between them. However, there was no visual sign of interaction between the two. How could this be possible?


That's ironic, if they saw evidence of interaction they would just ignore it anyway, just as they have with the findings of Dr. Halton Arp.

http://www.halton...articles
yyz
5 / 5 (7) Dec 31, 2012
Valeria, if you took the time to read what you linked to, you might have read that studies of NGC 5011C from the 1980's gave an (erroneously) high redshift to this galaxy, implying it was a member of the Cen Galaxy Cluster. In 2007, a new study using spectra and shallow imagery (using the 3.6m ESO scope at La Silla) of the galaxy found a much lower redshift, indicative of membership in the nearer Cen A Group, as well as a mass more in line with dwarf galaxies(~8x10^6 Msun). This new imagery also revealed, for the first time, the incipient resolution of NGC 5011C, another indication of its membership in the nearby Cen A Group: http://arxiv.org/...=0701280

There's no claim in the article that HST was the first to resolve this issue (pun intended) and in fact the deeper Hubble images were acquired for use in a (as yet unpublished) follow-up study of the stellar population and a new, independent distance determination (using techniques other than spectra) of NGC 5011C.
Q-Star
3.4 / 5 (11) Dec 31, 2012
If the two galaxies were at roughly the same distance from Earth, they would expect the pair to show signs of interactions between them. However, there was no visual sign of interaction between the two. How could this be possible?


That's ironic, if they saw evidence of interaction they would just ignore it anyway, just as they have with the findings of Dr. Halton Arp.


Ironic? Do ya know what that means?

So they didn't ignore something they expected they should see, but didn't see?

But if they had if they had seen what they expected to see they would have ignored it?

Now, let's go over ignore once more. Some of Arp's papers are held in high esteem. And some were talked about and found to be lacking, as in unconvincing, but none were ignored. A person who becomes tenured at Caltech, is never ignored. They disagree with him, but that is not the same thing as ignored. All men of science have one or two (or more) ideas that turn out to be wrong.

LED Guy
5 / 5 (9) Dec 31, 2012
Some of Isaac Newton's writings are still held in high regard. Others have been discredited, such as his corpuscular theory of light in which held that light refracted as a result of acceleration as light transitioned into a denser medium. Newton's ideas on light completely ignored the interference phenomenon (anything related to the wave nature of light).

Then there were Newton's studies and writings on the occult . . .

We can't be right all of the time.

Arp was correct on some things. That doesn't mean everything he wrote was correct.
that_guy
5 / 5 (5) Dec 31, 2012
While I don't know the true situation that happened among the cosmological community here, I think the "Laymen" have a point:

There are multiple clues here (granularity of the foreground galaxy, lack of interactions, or basically every property of the foreground galaxy).

It is bad science to base a conclusion on one piece of evidence (An apparently erroneous redshift measurement?) in the face of multiple pieces of contrary evidence.

However, as is often the case, good science does prevail - Even if the original conclusions *obviously* should have been more thoroughly checked, like they do with the LHC data.

I gave all reasonable comments a 5 that pointed this out. Just because they're laymen doesn't make every observation they make invalid. Anyone who follows astronomy would have reasonably noticed the discrepancy.
cantdrive85
1.4 / 5 (11) Dec 31, 2012
Q, please advise which Arp's findings are "acceptable", and which are not. He has spent the last 40 years researching anomalies in red-shift, is it all for nothing? Are you suggesting we can magically see through galaxies to see quasars behind them? Are any of the papers on his website "acceptable" to you, or are they all lacking?
http://www.halton...articles

I could use help on deciphering what is "good science" and what is not, thanks in advanced.
cantdrive85
1.4 / 5 (10) Dec 31, 2012
Q, Please give me an explanation for NGC 7603 (Seyfert Galaxy) and the high redshift anomalies that are present within the filament that connects NGC 7603 with it's companion.

http://quasars.org/ngc7603.htm

I would also request you to read Arp's comments on his research with Fred Hoyle and explain again how a tenured Cal Tech alum is not ignored.

http://www.halton...ith_Fred
ValeriaT
1.5 / 5 (8) Dec 31, 2012
that studies of NGC 5011C from the 1980's gave an (erroneously) high redshift to this galaxy, implying it was a member of the Cen Galaxy Cluster
Yep, this is a miniature example of how so-called "scientific facts" actually work. Will you learn from it for future (Big Bang, cold fusion, aether theory)? I seriously doubt it.
Q-Star
2.8 / 5 (9) Jan 01, 2013
Q, Please give me an explanation for NGC 7603 (Seyfert Galaxy) and the high redshift anomalies that are present within the filament that connects NGC 7603 with it's companion.


I could use help on deciphering what is "good science" and what is not, thanks in advanced.


Before I can do that, you must first study up on the advances in the observational technology and tools since the 60's. We've come a long way since then. And you would first have to waste some time learning the fundamental physics involved. (I realize you think is waste of time, but you couldn't understand any explanations without it.)

The rebuttals to Arp's more "fringe" views are quite abundant, probably run about 100 against to every 1 for (and the ones for are all mostly written by the same three or four people.) Google is your friend,,,, try it & you will get much more than I could possibly give in 1000 characters or less.

If he were ignored, all those rebuttals wouldn't have been written.
cantdrive85
1.4 / 5 (9) Jan 01, 2013
Tap tap tappity tap tap.... Still dancing.
Q-Star
2.9 / 5 (9) Jan 01, 2013
Q, Please give me an explanation for NGC 7603 (Seyfert Galaxy) and the high redshift anomalies that are present within the filament that connects NGC 7603 with it's companion.


See, this is why you are so frustrated with the astrophysical community. You accept some "odd" explanation for a rare observation to explain ALL phenomena. You start from an unproductive premise. That the exceptional can explain the usual.

Actually it is the opposite that gets you closer to the truth, the usual is where your general reality lay.

There are more galaxies in the observable universe than all the humans who have ever tread the earth, would you try to "theorize" on the human evolution using only blind dwarfs with clubbed feet as a basis?

To answer your question about the redshift "anomalies", if you knew that there are several different mechanisms involved in the "phenomena" of redshifts you wouldn't ask such a uninformed question.

Psst, hint,, look for three kinds of redshift and read.
cantdrive85
1 / 5 (8) Jan 01, 2013
Q, Please give me an explanation for NGC 7603 (Seyfert Galaxy) and the high redshift anomalies that are present within the filament that connects NGC 7603 with it's companion. http://quasars.org/ngc7603.htm


The paper related to this anomaly was produced in 2002, the question still stands.
http://arxiv.org/.../0203466

I'll let the Arp question go for now, with the understanding that I am wrong whether or not Arp is ignored.
cantdrive85
1 / 5 (7) Jan 01, 2013
Although I was aware of the different aspects of redshift (which ignores other possibilities beyond the three), I have another question. Only two of the three types of redshift are applicable to this observation, Doppler and Cosmological (gravitational apparently doesn't apply here due to distance and mass involved). The problem I see with this is that "cosmological" redshift is based upon the "expanding universe" hypothesis which seems completely circular in reasoning. Playing devil's advocate, IF Arp is correct that the Universe is not expanding, what role does the "cosmological" redshift have in reality? Also, where do these theories discuss the possibility that photons traveling through a plasma can also affect redshift?
http://arxiv.org/.../0401420
Q-Star
1 / 5 (4) Jan 01, 2013
The problem I see with this is that "cosmological" redshift is based upon the "expanding universe" hypothesis which seems completely circular in reasoning. Playing devil's advocate, IF Arp is correct that the Universe is not expanding, what role does the "cosmological" redshift have in reality?


But you see, I don't hold to the steady state universe so I wouldn't know how to argue for it.

Is there any possible way the that radial velocities of the objects as viewed from Earth might have different magnitudes? Is the so called "filament" actually moving with the same speed and in the same direction as the galaxies? That would be a simpler answer then new physics.

Are the "filaments" being accelerated by by some condition above & beyond the motion of the group as a whole? That would be simpler than new physics.

Yes magnetic currents in the plasma could affect the redshift, by channeling & accelerating the less dense material in the filaments. Again simper than new physics.
Fleetfoot
4.3 / 5 (3) Jan 01, 2013
.. gravitational apparently doesn't apply here due to distance and mass involved).


Gravitational does have an effect but it depends on the source mass so is independent of distance. It doesn't affect the slope of the distance/redshift plot.

The problem I see with this is that "cosmological" redshift is based upon the "expanding universe" hypothesis which seems completely circular in reasoning.


No, it is an observed empirical releationship between redshift and distance obtained by other methods:

http://en.wikiped...e_ladder

Also, where do these theories discuss the possibility that photons traveling through a plasma can also affect redshift?


A) Plasma effects are frequency dependent, cosmological redshift is not.

B) Plasma effects would not cause time dilation such as is seen in supernovae light curves. A simple way to think of that is that the downward side of the pulse is sent from farther away than the rising side.
Jonseer
1 / 5 (2) Jan 01, 2013
wouldn't the fact that individual stars in the dwarf galaxy can be made out as tiny dots vs a vs. the spiral which no such thing can be seen have clued in the astronomers?

Something is missing from this article to make it seem like astronomers simply didn't notice this.
barakn
5 / 5 (1) Jan 01, 2013
Q, Please give me an explanation for NGC 7603 (Seyfert Galaxy) and the high redshift anomalies that are present within the filament that connects NGC 7603 with it's companion.

http://quasars.org/ngc7603.htm -cantdrive85

"THe camera was slightly mispointed, which also is typical when trying to work with such precision over such distances. Part of the galaxy was lost, see the small inset for the whole galaxy." Here we have the author Eric Flesch displaying his ignorance of Hubble's Wide Field and Planetary Camera 2. The image is divided into 4 quadrants, 3 of which are the Wide Field Camera. The 4th is the Planetary Camera, and it uses different optics to show a zoomed-in, higher resolution image. If one desires to combine all 4 in one image, this 4th one has to be rescaled to fit together with the other 3, hence the numerous Hubble images that - rather than being perfectly square - have one jagged corner. NGC 7603 is perfectly centered in the Planetary Camera image.
barakn
5 / 5 (2) Jan 01, 2013
It is obvious that Hubble was specifically and accurately pointed so that that the Planetary Camera could capture a high resolution image of the galaxy's core. The interesting stuff in the Wide Field Camera was pure gravy. I am not claiming here that there's no legitimate controversy surrounding NGC 7603, but I am pointing out that cantdrive85 will find unerringly the nuttiest, most crackpot sites written by the most clueless of authors that he can find on the subject.
lengould100
5 / 5 (3) Jan 02, 2013
http://science.slashdot.org/story/11/06/01/1937220/why-we-have-so-much-duh-science. Someone should check, if the money of tax payers were really invested into serious research in this particular case and people responsible punished for it. The contemporary science completely lacks the public feedback and scientists itself aren't willing to control to check their own spending. In Czech we have a proverb: "The carps never empty their own pond".
I'd argue that the present system produces far better science than allowing laypersons like you (or myself) to decide what gets funded.
ValeriaT
1 / 5 (6) Jan 02, 2013
I'd argue that the present system produces far better science than allowing laypersons like you (or myself) to decide what gets funded
I'm against every form of socialism and planned economy in science, but the science itself is mandatory fees based and as such communistic by its very nature. So we need to capitalize basic research more, not less. That is to say, the orientation to basic research has lead the mainstream science outside of the basic needs of the human society, which has to pay it somehow. Now I'm talking mainly about ignorance of cold fusion research, which keeps the economical state of human society low and it brings the risk of global geopolitical crisis, leading into nuclear WWW III. The finding of Higgs boson is nice, but it will not feed us, the scientists the less. And it will not replace the oil and save life environment. The scientists will be first, who will suffer with their own ignorance.
ValeriaT
1.6 / 5 (7) Jan 02, 2013
BTW the scientists itself (i.e. highly specialized experts) aren't any better in strategical decisions more, than any other layman. In this context the reading of articles The era of expert failure by Arnold Kling, Why experts are usually wrong by David H. Freeman and Why the experts missed the crash by Phill Tetlock may be useful. How some relativistic physicist could reliably judge the relevance and usefulness of cold fusion finding, for example? He's (un)qualified for it in the same way, like every average climatologist or evolutionary biologist, for example. The scientific community as a whole just avoids all opportunities, which would threat the job positions in existing research.
cantdrive85
1.4 / 5 (9) Jan 02, 2013
Q,
I appreciate the answers, although I'm surprised Arp wouldn't have considered those "simple answers" when he studied and documented these anomalies. And contrary to your claims, I'm in no way suggesting "new physics" (unlike dark whatever), I'm suggesting a reapplication of what is already understood, you are very gifted at inserting the strawman arguments.

Fleet,
The distance ladder (based on standard candles and such) is still based upon assumption and theory, hence more circular reasoning.

Q-Star
1.7 / 5 (6) Jan 02, 2013
strawman


You keep saying that,,,, but what does it mean? To you? Because I think you are using it differently than most people use it. (Metaphysical is another you overly misuse also.)
cantdrive85
1.5 / 5 (8) Jan 02, 2013
Strawman- a type of argument based on misrepresentation of an opponent's position.

Metaphysics is a traditional branch of philosophy.

As Tesla said of the purveyors of GR;
"...magnificent mathematical garb which fascinates, dazzles and makes people blind to the underlying errors. The theory is like a beggar clothed in purple whom ignorant people take for a king ... its exponents are brilliant men but they are metaphysicists, not scientists..." New York Times, July 11, 1935, p23, c8

Q-Star
2.8 / 5 (9) Jan 02, 2013
I thought (correctly) that you were misusing it.

"To "attack a straw man" is to create the illusion of having refuted a proposition by replacing it with a superficially similar yet unequivalent proposition (the "straw man"), and to refute it, without ever having actually refuted the original position."

I didn't replace anything of what you proposed, nor did I misrepresent anything you proposed.

The metaphysics you use incorrectly also. Just because you don't understand the physics, or don't agree with the theories and primeses, doesn't make it metaphysics.

Metaphysics doesn't mean "I don't like it" or "I sound erudite when I use words like metaphysics even when I use them incorrectly".
Fleetfoot
5 / 5 (2) Jan 02, 2013
The problem I see with this is that "cosmological" redshift is based upon the "expanding universe" hypothesis which seems completely circular in reasoning.

...

The distance ladder (based on standard candles and such) is still based upon assumption and theory, hence more circular reasoning.


You don't seem to understand what "circular reasoning" means. The basis of the distance ladder is parallax which is simple geometry, not dependent on any astronomical model. Neither that nor any of the following steps are based on expansion so there is no circle in the reasoning.

If you or Arp's speculations are not compatible with the Hubble Law, they are proven wrong by observation.
cantdrive85
1 / 5 (6) Jan 02, 2013
Stellar parallax is only applicable to stars 1,600 light years and less, being that the Milky Way is 120,000 light years across, parallax offers a VERY limited observational technique of determining distance. Beyond that there are a great deal of assumptions and correlations that must be accurate, even Wiki discusses these possible short comings.
http://en.wikiped...e_ladder
Q-Star
2.7 / 5 (7) Jan 02, 2013
Stellar parallax is only applicable to stars 1,600 light years and less, being that the Milky Way is 120,000 light years across, parallax offers a VERY limited observational technique of determining distance. Beyond that there are a great deal of assumptions and correlations that must be accurate, even Wiki discusses these possible short comings.


The shortcomings don't disqualify the methods, they only constrain the results,,,, Something that has a plus or minus 10% error is very useful if that's all you have.

When you use several independent methods and acquire similar results, the confidence in the processes increases.

Knowing something at a distance of 8 billion light years, within plus or minus 1 light year is pretty good, don't you think?

Of course if the astrophysicists would incorporate plasma in their calculations, then we would get at the 8,007,999.002 light years that we know has to be true. That's the number we need, right?
Fleetfoot
5 / 5 (4) Jan 02, 2013
Stellar parallax is only applicable to stars 1,600 light years and less, being that the Milky Way is 120,000 light years across, parallax offers a VERY limited observational technique of determining distance. Beyond that there are a great deal of assumptions and correlations that must be accurate, even Wiki discusses these possible short comings.
http://en.wikiped...e_ladder


None of those assumptions or techniques are dependent on cosmological expansion so the reasoning is NOT circular. As I said, you do not appear to understand what the term means:

http://en.wikiped...easoning

The points in the Wiki page contribute to the uncertainty in the numerical value of the Hubble Constant, but do not affect the underlying linear relationship.

Understanding the impact of uncertainties in terms of random and systematic errors is 'good science', your insistent denial of the observations is called 'religion'.

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