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Dark Matter Stars in the Early Universe?
OriginalArlen writes "UniverseToday reports new research which suggests dark matter could have condensed to form 'dark stars' in the early universe. These stars would have been very massive and burned very slowly, fueled by non-fusion reactions, they could still be with us. Astronomers hope to better constrain theories of early galaxy and star formation with observations of gravitational lensing events caused by these ghosts of the primordial universe."
"Nothing for you to see here. Please move along."
Indeed.
Hmm... what if we discover a star like the one Asimov described in Nemesis? Yes, I know it wasn't a dark matter star, but they didn't see it, either.
On \. OriginalArlen reports the news. I look at the linked website, called Universe Today and I see that there is one "publisher" by the name of Fraser Cain. Following the link there, finally, I get to the article on the arxiv, the definitive source of new physics papers. So to get to the source, it takes three jumps. So what has Fraser Cain done for us? Watered down the content? Couldn't OriginalArlen read the article and write a gist himself/herself? Or is Fraser Cain the same person as OriginalArlen? Reading the original article, I find "some" correlation on what ends up on \. and what is in the article. Or is this not the point? If I had to write a review for this article, I would have said that the last sentence of the abstract is what is most important: "A ..star .. detectable via annihilation products (gamma-rays, neutrinos, anti-matter) possibly in combination with hydrogen lines."
The brilliant thing about this article is that these theorists are cooking up something that is actually detectable! Something that can be tested and hopefully will! *Finally* congrats to Douglas Spolyar, Katherine Freese and Paolo Gondolo, who *wrote* the article. (No, I dont know any of them. But isn't it time we cited those whose ideas we regurgitate?)
As matter clouds condenses, gravitational energy is released. This energy has to be radiated away for the collapse to proceed, as the collapse is opposed by the thermal kinetic energy of the matter in the cloud. This was a major problem in the early universe when the abundance of metals was so low that radiation cooling was less efficient. If dark matter interacts very weakly with normal matter and electromagnetic fields, cooling is going to be very slow indeed. We know that dark matter exists and that it forms concentrations on the scale of large galaxies. We do not have strong evidence for the concentration of dark matter in the solar system, where it could result in apparent radial variations in solar or planetary masses. I supect that cooling of stellar mass dark matter clouds is rather difficult. Once somebody figures out how to observe the stuff and its properties, we can better understand what we see and what we should be looking for.