Comic Microwave Background Courtesy of NASA / WMAP Science Team

Australian Student Uncovers the Universe’s Missing Mass

25 May , 2011 by

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Not since the work of Fritz Zwicky has the astronomy world been so excited about the missing mass of the Universe. His evidence came from the orbital velocities of galaxies in clusters, rotational speeds, and gravitational lensing of background objects. Now there’s even more evidence that Zwicky was right as Australian student – Amelia Fraser-McKelvie – made another breakthrough in the world of astrophysics.

Working with a team at the Monash School of Physics, the 22-year-old undergraduate Aerospace Engineering/Science student conducted a targeted X-ray search for the hidden matter and within just three months made a very exciting discovery. Astrophysicists predicted the mass would be low in density, but high in temperature – approximately one million degrees Celsius. According to theory, the matter should have been observable at X-ray wavelengths and Amelia Fraser-McKelvie’s discovery has proved the prediction to be correct.

Dr Kevin Pimbblet from the School of Astrophysics explains: “It was thought from a theoretical viewpoint that there should be about double the amount of matter in the local Universe compared to what was observed. It was predicted that the majority of this missing mass should be located in large-scale cosmic structures called filaments – a bit like thick shoelaces.”

Up until this point in time, theories were based solely on numerical models, so Fraser-McKelvie’s observations represent a true break-through in determining just how much of this mass is caught in filamentary structure. “Most of the baryons in the Universe are thought to be contained within filaments of galaxies, but as yet, no single study has published the observed properties of a large sample of known filaments to determine typical physical characteristics such as temperature and electron density.” says Amelia. “We examine if a filament’s membership to a supercluster leads to an enhanced electron density as reported by Kull & Bohringer (1999). We suggest it remains unclear if supercluster membership causes such an enhancement.”

Still a year away from undertaking her Honors year (which she will complete under the supervision of Dr Pimbblet), Ms Fraser-McKelvie is being hailed as one of Australia’s most exciting young students… and we can see why!


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Ariane Stevens
Guest
May 25, 2011 2:29 AM

Aussie, Aussie, Aussie, oi, oi, oi!!

(Pity they are mostly incoherent fields of only a few micro Gauss, though.)

Ian Manson
Guest
May 24, 2011 9:34 PM

I look forward to the day that chant finally dies and never re appears.
The British sing great long songs and all we can muster is a lousy 2 word chant…

Anonymous
Guest
Anonymous
May 25, 2011 9:23 AM

Waltzing Matilda is alright, and I’ve heard that sung at Aus v Eng rugby and cricket matches. Seeing as it’s a song about a criminal, you’re drawing directly on your country’s cultural lineage too!

Ian Manson
Guest
May 25, 2011 9:41 PM

Waltzing Matilda is brilliant. We are a land of low blood crims thats for sure!

Lawrence B. Crowell
Member
Lawrence B. Crowell
May 25, 2011 2:46 AM

This is somewhat unexpected. There are no links here, so I can’t read further. However, I am wondering if I am to presume this changes luminous and dark matter’s percentage in the universe from 4% and 24% respectively to something more like 8% and 20%. This is just based on the doubling statement in the article.

LC

Lawrence B. Crowell
Member
Lawrence B. Crowell
May 25, 2011 2:46 AM

This is somewhat unexpected. There are no links here, so I can’t read further. However, I am wondering if I am to presume this changes luminous and dark matter’s percentage in the universe from 4% and 24% respectively to something more like 8% and 20%. This is just based on the doubling statement in the article.

LC

the one
Guest
the one
May 25, 2011 3:20 AM

Comic Microwave Background Courtesy of NASA / WMAP Science Team(comic or cosmic)?

SkyGuide
Guest
SkyGuide
May 25, 2011 11:03 AM

Ouch!

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
May 25, 2011 7:27 PM

Comic or cosmic depends if you see the LOLCat face or not.

“I can haz cosmic cheezburger?”

Elwood A Anderson
Guest
May 25, 2011 3:32 AM

You go, girl! A good job that proves science is still a valid pursuit for promising students.

Greg
Member
Greg
May 25, 2011 7:39 AM

Unfortunately the details are sketchy as usual in the mainstream media with regards to how much”missing matter” was found. This is however measured evidence and appears to be legit. The findings are consistent with what was theorized. What is cool here is the methods where this student with technical expertise in the x-ray field pulled a rabbit out of a hat with the data which originally appeared inconclusive do to significant uncertainties.
This is a link to the abstract/article which is accepted but pending publication:

http://arxiv.org/abs/1104.0711

Steve Nerlich
Member
May 25, 2011 6:32 AM

I think the deal is that this study confirms Bregman’s prediction outlined here: http://arxiv.org/PS_cache/arxiv/pdf/0706/0706.1787v1.pdf

The universe recipe of 74% dark energy, 22% dark matter and 4% baryonic is unchanged. It’s just that Bregman predicted that a lot of the baryonic matter would be in the form of Warm-Hot Intergalactic Medium (WHIM) – or filaments. This appears to be confirmed now, so good science all round.

I’m not sure what the link with Zwicky is – who is not obviously cited in either the Fraser-McKelvie or Bregman papers, but might have missed something.

Lawrence B. Crowell
Member
Lawrence B. Crowell
May 25, 2011 1:28 PM
I read the paper, which does make a case for high signal statistics. Even for filaments restricted to superclusters this gives n = sqrt{S/jL}, S = surface brightness, j = emission coefficient, and L = length through filament, with ~ 5?. So the statistics look pretty good. The number density n is the 2.6×10^{-4}cm^{-3} for the X-ray energy in the range.9-1.3 kev . That is about 10^2 electrons per cubic meter. This is 2 orders of magnitude larger than H density in intergalactic space. Clearly this also means there are an equal number of protons per unit volume as well. This density of dark matter is about 2.4×10^{-22}kg/m^3 in a galactic halo, which corresponds to a figure somewhat… Read more »
William928
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William928
June 8, 2011 12:09 AM

Swimming in the deep end now, are we?

HeadAroundU
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HeadAroundU
May 25, 2011 1:59 PM

Very confusing article. grin

Hugo Raimer
Guest
May 25, 2011 9:48 AM

Ye I agree razz

Al Wilson
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Al Wilson
May 25, 2011 2:41 PM
Hugo Raimer
Guest
May 25, 2011 9:50 AM

I was studying mercury for a school project then I found this article and I only understood two words: year and a razz

Jon Hanford
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Jon Hanford
May 25, 2011 3:10 PM
I see the same confusion here as at other sites reporting this story. Dark matter is NOT directly mentioned at all in the paper. The paper discusses the discovery of X-ray emission from hot *baryonic* matter (gas) that was theorized to exist in filaments between galaxies and galaxy clusters. The original press release is rather vague and confusing on this matter (but it too has no mention of DM). Of course, this discovery does have implications for the study of DM in these filaments (useful in constraining DM models of filaments, for one), but this could be seen as peripheral to what is discussed in the paper (hence no mention of it there). I’m a bit confused too… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
May 25, 2011 5:53 PM

The UT article here appeared to imply a massive amount of matter was found, but in looking at the actual research paper this looks like a few percent adjustment in favor of luminous matter, but not a major shift in the distribution of matter in the universe. This might change the luminous and dark components of matter from 4.5% and 23% to 4.7% and 22.8% or something like that.

I suspect that most of this matter which is observed here, or inferred from ROSAT data, is gravitationally bound to dark matter in these filaments. The observed 10^2 baryons per m^3 may not be sufficient to maintain a structure bound by gravity from this matter alone.

LC

Anonymous
Guest
Anonymous
May 25, 2011 4:28 PM

A Nobel Prize ?

Jeffrey Scott Boerst
Guest
May 25, 2011 4:42 PM

This link is to an image from her Facebook page… She seems like a typical, care-free, goofy college student. I love it that the internet grants us the ability to immediately access information on a person at this level. It makes the sober text of a news article crackle to life, adding SO much more depth and ‘wholeness’ to it’s contents. Cute image of her and a dog, BTW… How cool. ‘^.^,

Anonymous
Guest
Anonymous
May 25, 2011 4:59 PM
The missing dark matter is due to the mistaken and unproven belief that Newton’s law of gravity is a universal law valid at cosmic distances although it is only based upon observations in our solar system. When used in conjunction with observations of motion of stars in spiral galaxies (by Vera Rubin) Newton’s gravitational constant does not agree with the observations unless massive amounts of dark matter is proposed to provide the necessary gravity to explain the cosmic observations. Actually basic physics equations suggest that for the observed balance of inward forces and outward forces of rotation show that the product of the central mass and the gravitational constant G is a linear function of distance r and… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
May 25, 2011 7:43 PM

LOL! When an observation comes up that tests the standard as consistent with observation (missing, not superfluous, matter), and now _more_ consistent, you take the opportunity to declare a problem?

We could abandon the standard cosmology, but only if you provide a theory that predicts all it does and something more. MOND or MOND type GR modifications doesn’t do that, and in fact it has failed to predict most anything that the standard model does.

NASA Pioneer 10/11 space probes.

The Pioneer anomaly is explained by proper analysis of the probes thermal radiation. If you go to the paper, you see that the predictions now are consistent with the observations.

Anonymous
Guest
Anonymous
May 26, 2011 1:14 AM

You contradict yourself. Current we need this mysterious dark matter for observations to match the theory. What Sol said is that if you base the theory on the observations, you don’t need to -add- dark matter to make things work.

Dark matter is, after all, the stuff that is required to MAKE the theory match observation/experimental results.

WaxyMary
Member
WaxyMary
May 26, 2011 2:50 AM
Ok, I’ll bite, provide a theory which can explain, in addition to these recent observations, ALL prior facts which are not in contention — in other words even those which currently support much of our standard model with DM as a part of the theory leading us to the standard model, which is, by your statement, a failed theory. Telling us we missed the point being made by Sol, which TL addressed correctly, is not providing us with much of anything testable. The observed data pulled from history along with careful study of all specific points over the years is what allows DM to remain a part of the current standard model. Please show how it (the standard… Read more »
Anonymous
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Anonymous
May 27, 2011 1:16 AM

I don’t have to prove anything. I’m just trying to get you to remember/realize that DARK MATTER is a fictitious substance used to make the current theories work. Dark Matter may be real … on the other hand, the currently accepted theories that rely on dark matter in order to match observations could be wrong.

It is obvious from your post, however, that you fail to understand this and do not wish to even consider it. So much for the Scientific Method …

WaxyMary
Member
WaxyMary
May 27, 2011 3:07 AM

Yes, you do have to prove — well, anything you claim is replacement for the current — ah, to the reaches beyond our kin with ya… I will not even ask you to explain how what I wrote gave you any impression the scientific method was to be discarded since you can not, the words are NOT there, the lines to read them between are not there either.

You are sidestepping and you will continue to do so. Aside from this I hope your stepping leads you to where you are happiest and the company pleasant –converse, chat, what have you. Enjoy what you can of life and please, do it soon.

Mary

Anonymous
Guest
Anonymous
May 28, 2011 2:28 AM
I’m very sorry, but I am having a great deal of trouble parsing your comment into common English. To answer the one mostly clear sentence on your first paragraph: What gave me the impression the Scientific Method was being discarded was your blatant disregard for the fact that “dark matter” is a filler value to make the existing, commonly accepted scientific theories match observed values and experimental evidence. If you think “dark matter” is a real substance because of this then you quite obviously do not understand HOW the Scientific Method works. I’m not side stepping anything. I’m stating that nobody on this planet knows for sure whether the fictitious substance commonly referred to as “dark matter” really… Read more »
WaxyMary
Member
WaxyMary
May 29, 2011 2:33 AM
I’ll make this as simple as you require. Try to follow along, here we go. Currently observations and measurements from a large number of variably different persons and methods are what give us the standard model. All of these observations are repeatable, measurable and coherent. Follow so far? From this you wish to subtract one of the ‘suggested (by observation and logic) unknowns’, and replace it with something _you_ can not name, have not posited yet and will never be able to describe, ever. Still with me? If I have I understood your non-reply correctly, then what you really are saying is ‘the Current Theory is FLAWED’, and have no other great or small additions to change this… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
May 29, 2011 6:34 PM
DARK MATTER is a fictitious substance No, it isn’t. For comparison, a fictitious force, which nevertheless exists, is an apparent force that is used for convenience. (Appears from acceleration of the non-inertial reference frame, not from physical interaction on the observed object.) Dark matter does not only unequivocally exist according to standard cosmology and observations such as the Bullet cluster. It is real matter, not “apparent”. The thing is that it is noninteracting with EM. There is nothing uncommon in that, we know of lots of baryonic examples (say, non-luminous gas). It is obvious from your post, however, that you fail to understand this and do not wish to even consider it. Standard cosmology is precisely _about_ considering… Read more »
Peter John Schoen
Guest
June 7, 2011 11:24 PM

RUBBISH!
Dark Matter and or Dark Energy is the direct result of a gross misunderstanding of proper physics! And in particular glazed over a very important aspect of Physics which involves Energy constructs..

Once proper Physics is applied and understood it will expose those advocates to dark matter and dark energy as frauds, who have NOT paid attention to the aforementioned details..

Peter John Schoen
Guest
June 7, 2011 11:16 PM
Consider this Mary, Our location is a Galaxy, and lets now consider we may be located beyond a theoretical event horizon to an observer located a considerable distance away from our Galaxy.. Now lets postulate that our local distances to us remain constantly x amount of light years away from each other, but to an observer beyond our Galaxy, we are in fact – situated at some point.. and mind you this point seems to that observer is shrinking, and yet to us it seems beyond our galaxy the Universe presents as doing the opposite.. Mind you to us that’s an accelerating expansion! And Blow me down thats exactly what Red-Shift detections suggest!.. Therefore it should be obvious… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
May 29, 2011 6:22 PM

No, I don’t contradict myself, see my comment. Nor do you point out such a contradiction. What you try to inject, again, is an irrelevant complaint to a working theory: “you take the opportunity to declare a problem?”.

Btw, are you saying someone named “Sol” is using several nyms?

Anonymous
Guest
Anonymous
June 6, 2011 1:31 AM

Catching all the nonsense is proving a challenge.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
May 25, 2011 7:23 PM

LOL, the missing subject matter.

They _do_ distinguish between search inside and outside the virial radius that Zwicky used. Tenuous, but the best link I can “predict” for now. (No possibility of confirmation – unless Plotner provides more data.)

David Frankis
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David Frankis
May 25, 2011 9:39 PM
Greg
Member
Greg
May 26, 2011 3:52 AM
The fact that these filaments are now proven to contain baryonic matter has numerous ramifications in the fields of galaxy formation, supercluster formation and evolution, and indeed the formation and evolution of the universe itself. Previous research looking for WHIM naturally focused on superclusters as that is where you would expect to find it. I did not initally think that baryonic matter in isolated strands would be superheated. So there needs to some explanation for what sustains this heating process. Dark matter is the likely culprit. Another worthwhile question is whether these filmanets are a relic of the big bang and inflation or is dark energy playing a role in their formation? Not just good science, great science… Read more »
Ariane Stevens
Guest
May 27, 2011 3:42 AM

WHIM is mostly fiction, more fiction than dark matter, let’s say.
jimhenson hiding just another avatar isn’t going to change opinion.

Plasma Physicist
Guest
May 28, 2011 9:31 PM
Please explain this. Scientists stated “if we’re looking very very long distances from earth, we’re detecting mass, but if we’re looking closer to earth we only see about half the mass we’re expecting to see.” The mass settled into filaments extending between clusters of galaxies. (1) Wouldn’t this mean, that a LOT more mass was already out there at very very long distances, that they didn’t know about? (2) Since these filaments contain million degree ionized baryons in the Universe, wouldn’t electro-magnetic forces in plasma ALSO have both attractive and repulsive forces, and mess up the measurements believed by Dark Energy, and even reduce the amount from 74% dark energy to something substantially less? The scientists stated that… Read more »
Yeahyouright
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Yeahyouright
May 28, 2011 12:01 AM

My son and I don’t understand this (he’s eight, I’m 48)

Sarah Collins White
Guest
Sarah Collins White
May 29, 2011 12:20 AM
Amelia, CONGRATULATIONS on your amazing discovery. As a fellow “undergraduate discoverer” I know what you must be going through. Great job, and the following diatribe is NOT directed at you. Now onto my rant for everyone else associated with this article… As a former Science Teacher, I have to protest to not only a professional scientist (Dr. Pimbblet) misusing a key scientific term, but a science based magazine erring as well!!! A “theory” is a scientifically accepted explanation of a phenomenon A “hypothesis” is a prediction To Dr. Pimbblet, Ms. Plotner, and the editor who let this article slip by… Shame on you for using theory instead of hypothesis! Science teachers have a hard enough time teaching our… Read more »
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