First stars might have been powered by dark matter

Feb 12, 2008 By Miranda Marquit feature

For a long time, scientists have assumed that the very first stars were powered by fusion, in processes similar to what goes on in present day stars. But a new theory is emerging to challenge that view. “The first stars were different in a lot of ways,” Katherine Freese, a theoretical physicist at the University of Michigan, tells PhysOrg.com.

Freese, along with Douglas Spolyar at the Unversity of California, Santa Cruz and Paolo Gondolo at the University of Utah in Salt Lake City, posit that dark matter annihilation was the source of energy that powered the earliest stars, formed about the time the universe was between 100 and 200 million years old.

If they are right, some of what we know about stellar formation – and the formation of the universe itself – could be called into question. Their work appears in Physical Review Letters with the title “Dark Matter and the First Stars: A New Phase of Stellar Evolution.”

“Annihilation means that matter goes into something else,” Freese explains. She says that everything has a partner opposite – matter and anti-matter, electrons and positrons. When these opposites meet, their identity is lost and the energy goes elsewhere. “Dark matter particles are their own anti. When they meet, one-third of the energy goes into neutrinos, which escape, one-third goes into photons and the last third goes into electrons and positrons.”

“In order for a star to form, in order for its matter to collapse into a dense object, it has to be able to cool off,” Freese continues. “We noticed that in the first stars something was competing with the cooling. The stars couldn’t collapse down small enough to get fusion going. But they were still giving off energy. They were in a phase we hadn’t discovered before.”

Freese describes how the first stars likely moved from the dark matter phase and into the fusion phase. “The annihilation products getting stuck is what allows the dark matter heating to stay inside the star, and is what prevents the star from collapsing into a fusion driven one.”

When all the dark matter is gone, Freese says, the star can collapse enough for fusion to take over inside the star. Hydrogen and helium atoms are forced together by this process to form new elements (carbon, nitrogen, oxygen and metals) until it becomes dense enough to collapse in on itself. Finally, the star goes supernova, spewing the new elements created in its core across the universe to be used in the formation of later stars.

“This new phase is only true in the first stars,” Freese insists. “The stars we see today are called population one stars. Earlier stars were population two stars. The first stars are referred to as population three stars. Our work is to modify how we believe population three stars developed. At first, they weren’t fusion driven.”

If Freese and her colleagues are right, it could change what we know about how stars are formed. “It adds a new phase of stellar evolution,” Freese says. She says that studying this theory will have to wait until 2013, when NASA is scheduled to launch the James Webb Telescope. “We call them dark stars,” Freese explains, “but they would still shine, looking a little different. They would be cooler than a fusion driven star. We hope the next phase telescope will be able to tell between the standard stars now, and what we think happened in the first stars.”

Until then, Freese and her peers will continue to speculate on the properties of the first stars, and try to figure out how the new phase in stellar evolution might have affected the timing of other developments in the universe. “It really gets into speculation here,” she says, “but this could affect the timing of the fist black holes, and the development of our own galaxy.”

Copyright 2007 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

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Iztaru
1.7 / 5 (3) Feb 12, 2008
Can someone help me here? I do not understand some things.

First, how do they know what a pair of dark matter particles will generate when they interact?

Second, if the article is right and the interaction of dark matter particles generates photons, shouldn't the galaxies be covered by some sort of shine that would be direct proof of the existence of dark matter?
Trippy
4.8 / 5 (5) Feb 12, 2008
Can someone help me here? I do not understand some things.

First, how do they know what a pair of dark matter particles will generate when they interact?


Because the article will be referring to a specific theory of Dark Matter - my understanding of dark matter theories suggests to me that they are referring to one of the theories of WIMPs, specifically, the idea that Dark Matter is made up of the lightest susy particle. Current susy theories predict that if this is the case, then when this particle does interact it releases Photons, Electrons, Positrons, and Neutrinos. This is something they're hoping to test with the LHC when it comes online.

Second, if the article is right and the interaction of dark matter particles generates photons, shouldn't the galaxies be covered by some sort of shine that would be direct proof of the existence of dark matter?


That would be the general idea, yes, only the light is very faint, and made of Gamma rays of very specific wavelengths. For a while there was speculation that (some of) the Gamma rays in the direction of the Milkways core were being produced by exactly this mechanism and GLAST was expected to be able to clarify this, however, more recent higher resolution observations have called this into question.

Remember though that the WIMP theory of dark matter means [b]WEAKLY[/b] Interacting Massive Particles not NON Interacting Massive Particles.
manifespo
1.5 / 5 (4) Feb 12, 2008
I agree Mr Grynch.

What if normal stars are driven by fusion?

and

What if black holes aren't holes at all, and they constitute in actuality a class of star so much more powerful than the normal fusion star, held together by the dark energy of dark electricity?
hudres
1.7 / 5 (3) Feb 12, 2008
Since it has been pretty well established that there is dark matter, can we expect to find "Dark Anti-Matter" in the near future? Does this help balance the equations of the universe?
tomphys
2.3 / 5 (3) Feb 12, 2008
Dark matter is accepted by much of the scientific community as having to exist. What is not accepted so generally is what it actually is, predictions like this are theroies based upon theories-risky but mayb provide models which can be used to gain different insight into the nature of dark matter.

One problem with this theory, is what property of dark matter would stop such stars being formed today?
Also some of the oldest stars are still around, for example in the globular clusters around the milky way. Does the time scale over which such dark matter powered stars encompass the lifetime of these stars?
Surely there would be observational evidence beyond pen and pencil
zevkirsh
1.3 / 5 (3) Feb 12, 2008
our the universe is one giant exploded black whole
gopher65
3.5 / 5 (2) Feb 12, 2008
"One problem with this theory, is what property of dark matter would stop such stars being formed today?"

That particular conjecture (it is in NO way a theory) states that Dark Matter particles annihilate each other when they come in contact with each other. If this were true then the amount of DM in the Universe would have quickly decreased below the critical level necessary to sustain stars such as the ones talked about in this article. If this conjecture were true then there simply wouldn't be enough Dark Matter around today to prevent the formation of normal Fusion Powered stars.
tomphys
2 / 5 (3) Feb 12, 2008
I cant see the amount of dark matter in a star being much more than utterly negligible compared to the quantity in the universe-particularly as no dark matter interactions beyond gravitational effects are abserved.
I dont see how something that accounts for more mass than that observed can be suffering from sparsity and vast reduction since the beginning of the universe-unless it transits to dark energy-not something you would have thought would be due to star formation
lysdexia
2 / 5 (5) Feb 12, 2008
Existing stars are not powered by fusion, and neither were the first stars. All stars are powered by the same thing...electricity.

http://www.thunderbolts.info/


thunderbolts.info and MrGrynch are retarded bullshit. Read the rebuttals.
brant
2 / 5 (4) Feb 12, 2008
No lysdexia, Dark Matter, Dark energy, Dark fluid, and now dark matter stars, is retarded Bullshit.

That shit does not exist. It is the result of a mathematical error in judgment.

A real scientist told me the other day that the theoreticians, in his experience "always get it wrong"!
Havent you been reading about the million degree plasma in space.
There is no thermal process that will create that temp in space.
But its only 100eV(electron volts). One small double layer.
tsEnigma
2.3 / 5 (3) Feb 12, 2008
there is no "Dark" Anything!

Those theory's are only used to cover ignorance!
tomphys
4.3 / 5 (3) Feb 13, 2008
there is no "Dark" Anything!

Those theory's are only used to cover ignorance!


Dark matter, It is a name given to something we cannot explain that really exists. Even if it turns out to be some kind of theoretical error, the observational evidence is there and dark matter is just a name we label the anomaly with.
It doesnt have to be taken too literally, but needs an explanation

A real scientist told me the other day that the theoreticians, in his experience "always get it wrong"!

So wrong, I believe in physics by observation as much as theory-but you cant dispute history-theory can lead to observations as much as explain old ones
saucerfreak2012
1.5 / 5 (2) Feb 14, 2008
Ugh, more "Dark Matter" nonsense... All we see is an observable effect. How can we say anything more than that? Why not "Anomalous Gravitational Density" or even "Dark matter EFFECT" something less hokey and mystical than "Dark Matter". DM can be anything from: "...WIMPs and axions, astronomical bodies such as dwarf stars and planets (collectively called MACHOs), primordial black holes and clouds of nonluminous gas. Also, matter which might exist in another universe but might affect ours via gravity, would be consistent with some theories of brane cosmology". [http://en.wikiped...k_matter]

So hey why not throw all these things into 1 bucket and slap a fancy funding-friendly name on it like "Dark Matter",... that would be cool.
tomphys
2 / 5 (2) Feb 15, 2008

and dark matter is just a name we label the anomaly with.


pretty much what i was saying, but thats what its been called now...

Noumenon
2 / 5 (2) Feb 16, 2008
Science uses labels all the time to confine causes of effects observed, to be lator decomposed into more labels with additional understanding. Newton did this with 'gravity' which was lator decomposed by Einstein. I see no problem with using the label 'dark matter' in this way, as long as its not regarded as a physical entity before its verification.
TimESimmons
1 / 5 (3) Feb 18, 2008
So many crazy theories its getting difficult to maintain my crackpot reputation. There is no dark matter.

http://www.presto...ndex.htm
JoSimon
2 / 5 (2) Feb 19, 2008
@ brant
I wonder what kind of "real" scientists you talk to, but if they are any good they should give you a course in know-what-you-talk-about.
You stated that there could be no million-degree plasma in space, since the processes there would only involve energies of about 100eV.
To convert 100eV into Joules we multiply by the electric elementary charge: 1.602E-19.
The energy is then 1.602E-17 J. To link an enery with a temperature we use the simple formula E=k*T (where k is the constant of Boltzmann). You will find that the enery of 100eV does correspond to a temperature T of 1160322.78... Kelvin. So you tried to tell us, that there are no million-degree plasmas, because they can only have temperatures of about a million degrees? That is funny, but it ain't smart.
Weir
1 / 5 (1) Mar 03, 2008
What if there is no spacetime continuum? What if space and time derive from the discontinuous projection of matter? If atoms are independently and synchronously projected from their quantum energy equivalents in a timeless and spatially indeterminate quantum field that is orthogonal to the integrated fabric of space-time, then a different interpretation of gravity emerges naturally.

From this quantum relativistic approach the need for dark matter to explain the missing mass disappears. Matter is not free to move at the beck and call of gravity because the complex patterns of angular inertia in the universe as a whole require a preponderance of synchronicity in the primary projection of matter.

There is direct evidence of this in Foucault's pendulum. The swings of the pendulum may be driven by the earth's gravity but they are independent from the earth's rotation. Since the direction of the pendulums swings remain constant with the fixed stars and not with the earth's rotation they are synchronous with the primary projection of matter in the universe as a whole.

General relativity offers no satisfactory explanation for this. Without a spacetime continuum there is no basis for a Big Bang. Galaxies become cells creatively regenerating there own stellar populations. Alternate explanations emerge for the red shift and background radiation. There is more on this in website articles entitled "Gravity and Historic Coordinates," "Unified Theories, Fantasy, & Cosmic Order," and various others at www.cosmic-mindreach.com .