The gravitational lens B1938+666 as seen in the infrared when observed with the 10-meter Keck II telescope. Credit: D. Lagattuta / W. M. Keck Observatory

Distant Invisible Galaxy Could be Made Up Entirely of Dark Matter

18 Jan , 2012

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Astronomers can’t see it but they know it’s out there from the distortions caused by its gravity. That statement describes dark matter, the elusive substance which scientists have estimated makes up about 25% of our universe and doesn’t emit or absorb light. But it also describes a distant, tiny galaxy located about 10 billion light years from Earth. This galaxy can’t be seen in telescopes, but astronomers were able to detect its presence through the small distortions made in light that passes by it. This dark galaxy is the most distant and lowest-mass object ever detected, and astronomers say it could help them find similar objects and confirm or reject current cosmological theories about the structure of the Universe.

“Now we have one dark satellite [galaxy],” said Simona Vegetti, a postdoctoral researcher at the Massachusetts Institute of Technology, who led the discovery. “But suppose that we don’t find enough of them — then we will have to change the properties of dark matter. Or, we might find as many satellites as we see in the simulations, and that will tell us that dark matter has the properties we think it has.”

This dwarf galaxy is a satellite of a distant elliptical galaxy, called JVAS B1938 + 666. The team was looking for faint or dark satellites of distant galaxies using gravitational lensing, and made their observations with the Keck II telescope on Mauna Kea in Hawaii, along with the telescope’s adaptive optics to limit the distortions from our own atmosphere.

They found two galaxies aligned with each other, as viewed from Earth, and the nearer object’s gravitational field deflected the light from the more distant object (JVAS B1938 + 666) as the light passed through the dark galaxy’s gravitational field, creating a distorted image called an “Einstein Ring.”

Using data from this effect, the mass of the dark galaxy was found to be 200 million times the mass of the Sun, which is similar to the masses of the satellite galaxies found around our own Milky Way. The size, shape and brightness of the Einstein ring depends on the distribution of mass throughout the foreground lensing galaxy.

Current models suggest that the Milky Way should have about 10,000 satellite galaxies, but only 30 have been observed. “It could be that many of the satellite galaxies are made of dark matter, making them elusive to detect, or there may be a problem with the way we think galaxies form,” Vegetti said.

The dwarf galaxy is a satellite, meaning that it clings to the edges of a larger galaxy. Because it is small and most of the mass of galaxies is not made up of stars but of dark matter, distant objects such as this galaxy may be very faint or even completely dark.

“For several reasons, it didn’t manage to form many or any stars, and therefore it stayed dark,” said Vegetti.

Vegetti and her team plan to use the same method to look for more satellite galaxies in other regions of the Universe, which they hope will help them discover more information on how dark matter behaves.

Their research was published in this week’s edition of Nature.

The team’s paper can be found here.

Sources: Keck Observatory, UC Davis, MIT

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James Young
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James Young
January 18, 2012 11:52 PM
I don’t profess to be an expert but I’m continually dismayed by scientists jumping on this dark matter nonsense. If it’s completely proven, GREAT, but everything I’ve read says it’s really just a guess because we don’t know (like the old aether we used to have). Why can’t this satellite simply be a singularity that has consumed it’s matter and is surrounded by a mass of dust or rocks or whatever’s left? As a low-mass satellite it’s within the realm of reality that this could be a normal phenomenon and we’re seeing this satellite completely dead or in a stage where it has yet to form (re-form?) stars… perhaps the singularity affects that process in ways we don’t… Read more »
Tristan
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Tristan
January 19, 2012 12:42 AM

People were skeptical about the very existance of singularities, too, before it was possible to study their effects the way they’re doing now. Technology is always behind theory, so future generations will probably have the means to figure out if dark matter and energy really exists, or there’s something wrong with our theories.

Torbjorn Larsson OM
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Torbjorn Larsson OM
January 19, 2012 1:00 AM
Well, I am continually dismayed by people rejecting accepted science. And contributes by posting the same erroneous nag on science sites, to no worthwhile result. So YMMV. Dark matter is a vital part of the current standard cosmology. So it is very fruitfully engaged with other theory. It is not nonsense, it is not a guess, it is not a mathematical equation “placeholder”. It is also observable all by itself, by various gravitational effects such as described here. It is the only theory that predicts such observations of cluster collisions, where dark and standard matter behaves differently. It is not an aether or phlogiston theory that failed its first meeting with observations that could test it. It is… Read more »
squidgeny
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squidgeny
January 19, 2012 12:26 PM

How can we expect “something more plausible” than the single remaining theory (at this time)?

Well said. As a certain fictional detective once quipped: “When you have eliminated the impossible, whatever remains, however improbable, must be the truth”

James Young
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James Young
January 19, 2012 11:56 PM
“Dark matter is a vital part of the current standard cosmology. So it is very fruitfully engaged with other theory. It is not nonsense, it is not a guess, it is not a mathematical equation “placeholder”” If it’s been completely proven, like I said… GREAT. But it’s not. It’s a great fit for trying to figure out some mysteries… I’m not saying I don’t completely believe that it could be there… I just feel that a LOT of articles are relying on it because they have absolutely no clue or other theory… when that happens people will get lazy and start saying… HEY… it must be Dark Matter… it must be Dark Energy… instead of actually trying to… Read more »
Anonymous
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Anonymous
January 22, 2012 7:25 PM
Well, you should know that the articles you “feel” are lazy are not official lab notes from the experiments and observations. Nor are they written by the scientists that performed/observed anything. The whole point of journalism is to organize news for the lay person to understand. If you are looking for more in-depth analysis of findings, you should refer to the scholarly journals, as those are peer-reviewed. Or, if you here to just be blindly critical, you should focus on the manner in which scientific data is reported by journalists. Also, what is your standard for completely proven? You make it sound like no matter how much observation or how many experiments support a given theory or how… Read more »
Anonymous
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Anonymous
January 19, 2012 1:29 AM

It would be nice if we could find one of these fellas nearer by.

Yatin Dhareshwar
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Yatin Dhareshwar
January 19, 2012 2:20 AM

There may be some purpose and reason for dark matter to exist after all.

My theory on the birth of the Universe – as an emergent phenomenon from self-organizing dark matter – http://ydessays.blogspot.com/2012/01/case-for-emergence-as-cause-of-birth-of.html

Lawrence B. Crowell
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Lawrence B. Crowell
January 19, 2012 1:21 PM
The emergence of the universe likely has more to do with dark energy. This is most probably due to the quantum vacuum energy of the universe which is evenly distributed. This is difficult to understand, for it requires knowing the quantum states or vacuum structure of the universe. To do that requires understanding how gravity or quantum gravity has a vacuum state tied to the rest of quantum fields. Dark matter is due to a number of plausible sources. One is supersymmetry, where DM is composed of the supersymmetric partners of ordinary matter. Another is that DM is the dilaton or axion field in a state of broken symmetry or very low temperature. LC
WaxyMary
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WaxyMary
January 19, 2012 3:20 PM

LC, Yatin Dhareshwar is using the word emergent in a different capacity than your answer addresses, or at least from what I read of his posted URL.

Mary

Yatin Dhareshwar
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Yatin Dhareshwar
January 20, 2012 2:06 AM

Yes, WaxyMary is right – I do not mean emergence as in arrival or appearance, but emergent as in the phenomenon, examples of which may be found in this link – http://www.pbs.org/wgbh/nova/nature/emergence-examples.html

Anonymous
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Anonymous
January 19, 2012 11:51 PM

Thanks moderator! Once again, UT’s moderation policy is helping to make this site awesome.

Yatin Dhareshwar
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Yatin Dhareshwar
January 20, 2012 2:26 AM
I did not reproduce my theory in its entirety as it would deflect from the central theme of the main article being discussed here. So, the link would have given a choice to those genuinely interested to read it and others to skip it. If there is a provision for reproducing my article in full on this site, please do let me know and I am keen to throw my ideas open for discussion and debate. Lastly, the “personal theory promotion URL deleted” was sufficient and reasonable indication on why the URL has been deleted and I completely understand and have no arguments. If that is the policy of this site, then so be it. However, the “go… Read more »
Anonymous
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Anonymous
January 20, 2012 9:14 PM

I corrected the issue by the moderator.

Please avoid personal theories in the future.

Anonymous
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Anonymous
January 27, 2012 1:25 AM

Moderator, but Eugene the brown dwarf and the spaghetti monster are not personal theories but gleaned from modern scientific thought. Lighten up.

Now the towel-dude is straight for the seminal work of science; The Hitchhikers Guide. A first person account
Yet to be disproved, might I add

colin
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colin
January 19, 2012 4:20 AM

Quick question – I looked at the image above and read the article. For the life of me I can’t figure out what is supposed to be the dark matter galaxy… If, I’m understanding the article correctly, the light spot in the middle is the foreground galaxy around which an Einstein ring has formed. Now somewhere in the ring is evidence of a dark matter galaxy?

I wish these pictures came with arrows and explanations so that laymen like myself could understand what we are looking at more clearly.

Al Wilson
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Al Wilson
January 19, 2012 3:29 PM

Seconded. I’m confused by the following: “This dwarf galaxy is a satellite of a distant elliptical galaxy, called JVAS B1938 + 666 […] and the nearer object’s gravitational field deflected the light from the more distant object (JVAS B1938 + 666) as the light passed through the dark galaxy’s gravitational field”

The above sounds contradictory – is the dwarf galaxy orbiting the background elliptical, or is it the foreground lens? Intuitively, I would have to say the dark dwarf must be the foreground lens, which is how we can determine its mass. If it orbited the background elliptical, we would only see the distorted light of the elliptical.

Al Wilson
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Al Wilson
January 19, 2012 3:39 PM

Nevermind. The original Keck release says “map any excess lens mass that could not be accounted for by the galaxy” – so the dark dwarf + elliptical is the lens/foreground object…

Anonymous
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Anonymous
January 27, 2012 1:20 AM

It is clearly represented by the dark arrow and annotations. You need your 18d dark glasses

Anonymous
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Anonymous
January 19, 2012 4:46 AM

>This dark galaxy is the most distant and lowest-mass object ever detected,

Ummm… if the dark galaxy is lensing the light from another galaxy, then the other galaxy must be further away than the dark dwarf, no? So the dark dwarf can’t be the most distant object ever detected. And in terms of mass, I’ve just detected a bread crumb on my keyboard….

I’ve just read through the Keck press release which is a little clearer than the UT article, but it’s not a paragon of lucid writing either. I think what they’re saying is that this object is the lightest and most distant dwarf galaxy detected.

Pvt.Pantzov
Member
January 19, 2012 7:52 AM

“‘…or there may be a problem with the way we think galaxies form,’ Vegetti said.”

Spectrum7Prism
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Spectrum7Prism
January 19, 2012 2:23 PM
Well, as one who does not buy-into the mainstream hypothetical formulations of how objects in our Universe came to exist, be they Star Worlds, or elegant star-system Galaxy realms, arrayed in cerebral-like pattern formations, strewn throughout the space-expanding Universe of time, I anticipate that “there may [ indeed ] be a problem with the way we think galaxies form”. If you build your models on the wrong premise, the established theoretical pictures depicting celestial formations will eventually prove illusory: Is the Universe a product of chance occurrence, or a deliberate Work of Intelligent Creation? What do the established facts show, in contrast to embedded , and thus far, unproven theories that contradict a possible Construction of Mind? Is… Read more »
WaxyMary
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WaxyMary
January 19, 2012 3:33 PM
Spec, you seemingly wish to argue ‘the scientific method’ vs ‘the supernatural belief system’ — so, rather than advance speculation as you are herein doing with your leading questions would you please advance a specific system of formation and cite specific facts or experimental results which would lend credence to your, admittedly prosaic, assumptions as reflected in your speculations of something other than a ‘timeless acident’. Additionally I know of no one who attributed human ‘organizational systems and causes’ to material systems, yet you imply those very same systems to the universe in your third paragraph. BTW, your scansion and meter, foot and lead for your uninformed prose limp rather than soar, and led us to nowhere rather… Read more »
Spectrum7Prism
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Spectrum7Prism
January 19, 2012 6:40 PM
Speculation? None to see in star-configurations of Astronomy’s constellations? Surely, it is all established fact – unassailable? Well, there are Astronomers and Cosmologists who might disagree ( even if they reside in the minority ). The circumstantial evidence, Mary, is as broad as the ordered world itself, and as wide as the sky arrangement: Which gives it silent voice “night after night”: In signatures written by Universe governing laws, revealed in spectrum-breadth of prism light. The celestial panorama mirrors a greater reality than this space-time fabric of our woven existence, or “specific system of formation”. Sorry, Mary, I cannot explain to you how a galaxy is made; though you may feel confident to explain to me how one… Read more »
WaxyMary
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WaxyMary
January 19, 2012 8:08 PM
Spec, ‘Tested and Found Wanting” is the label which best explains your reply. You still use ten words where three would do. You have not answered the questions I asked nor can you… you do assume to ask questions, some of which do have answers and which fall under the veil of science. Do not ask “why is the sky blue” if the answer does not suit your belief system. It is plain, however, that you wish your “questions” to bear more of the weight than the structure you weave can support. Seeking answers, as you express, but providing ‘facts’ drawn from your beliefs, it seems you might need to explain to myself and all the rest here… Read more »
Spectrum7Prism
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Spectrum7Prism
January 20, 2012 12:43 AM
Mary, of too many words, tis true. My flawed pen of prose, to dispense; and of word, will TRY to condense. ___________________________________________ “…[I]t seems you might need to explain to myself and all the rest here just what is your agenda — what is your intent with these ‘non-questions your-assumption-inserted-here provided answers’. Additionally, the debate you are attempting to stir while claiming otherwise is actually NOT a debate.” My “agenda”? Mary, I love to write (ragged as it can be). Since boyhood, I have been in love with Astronomy. This UT website, and its generous comment feature, I do like. So, when moved, I express my views, sometimes, necessarily, from the point of a “Creationist”. There is my… Read more »
WaxyMary
Member
WaxyMary
January 20, 2012 2:00 AM

As before, you call in the supernatural wherein you see a need for explainable authorship. Science alone is all that is needed.

ID has been proven incorrect, flawed, as well as gathering too many of mean spirit, to ever be a science of truth.

There is no need to answer my actual questions at this point, the way you have dodged and weaved is evident to any wishing to discern your agenda to any deeper degree than you have admitted.

Mary

Spectrum7Prism
Guest
Spectrum7Prism
January 20, 2012 7:04 PM
In closing: Call “in the supernatural” – Something “authored” the Cosmos, something decidedly unnatural in property and action. Mary, I can no more prove that a Creator Being existed at the point of Universe-genesis, than one can prove that the theoretical cosmic “singularity” was the starting point. It is one possibility, I submit. To avoid stirring a hornets nest, I could have been less emphatic. “ID has been proven incorrect, flawed, as well as gathering too many of mean spirit, to ever be a science of truth.” Unfortunately, you have some grounds under that statement. The mean spirit comes from a lack of the unshakable confidence of persuaded conviction, I think (a faith-like belief, unsubstantiated, is present on… Read more »
Spectrum7Prism
Guest
Spectrum7Prism
January 21, 2012 10:23 AM
___________________________________________________________________ When asked by an astounded atheist, if he were in fact deeply religious, Einstein replied: Yes, you can call it that. Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in point of fact, religious. — H. G. Kessler, The Diary of a Cosmopolitan, (London: Weidenfeld and Nicolson, 1971), p.157; quoted in Einstein and Religion by Max Jammer (Princeton University Press, 1999) pp. 39-40. ___________________________________________________________________ “My religion consists of a humble admiration of the illimitable superior spirit who reveals himself… Read more »
magnus.nyborg
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magnus.nyborg
January 19, 2012 5:22 PM

It is scientificly clear how things came to existance:

It was the flying spaghetti monster who did it, and he is more powerfull than any intelligent mind.

Anonymous
Guest
Anonymous
January 27, 2012 1:17 AM

Ya but which one is the dude with the towel?

Olaf
Member
Olaf
January 19, 2012 8:49 PM

Your in wrong forum. Maybe you should find a religious site to debate this.

Also everyone knows that this universe was created by a big brown dwarf called Eugene. You can find proof in the chronicles of Eugene the all mighty. And when you look very carefully at every star, galaxy or even a flower you will see the happy face if Eugene channelling you that he created all this.

Spectrum7Prism
Guest
Spectrum7Prism
January 21, 2012 10:56 AM

“rant” — “To speak or write in an angry or violent manner”? No, I was protesting a slanting of the debate table, where one voice remains, the other is censored out.

As I cannot abide the comments shadowing my name in “Activity” of Disqus, some will be glad to know, I have signed out (unworthy of the honorable company of others, like great scientists of the past, who today, would be so removed from public forums, Universities and Institutes for believing what Albert Einstein believed, in essence).

The Eclipse is a fitting symbol indeed.

As one eclipsed, Finito.

Peter
Member
Peter
January 19, 2012 4:03 PM

Who wrote this? I might not take credit either. “most of the mass of galaxies is not made up not of stars but of dark matter”. Wow, follow that one. And the whole second paragraph is inserted in such a poor way as to assure that the reader has no idea where a “satellite” even comes into the equation. Also, to “explain” something is to make it clear. “meaning that it clings to the edges of a larger galaxy” is hardly a way to explain astrophysical behaviour. Babies and Koala bears cling. Galaxies, AFAIK, do not.

Baksa Péter
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Baksa Péter
January 19, 2012 6:58 PM

If it is invisible, how do we know that it is a galaxy? Or things above a certain mass are galaxies by definition?

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magnus.nyborg
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magnus.nyborg
January 23, 2012 6:18 AM

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