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Post Info TOPIC: Glow From The First Stars In The Universe
Blobrana


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Universe Dark Age
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 How the Universe Escaped its "Dark Ages"

An international team of astronomers has uncovered an important clue about how the Universe emerged from its "dark ages" some 13 billion years ago. By looking at nearby galaxies with the Subaru and Keck Telescopes, the team inferred what may have happened to the first galaxies of our Universe. By looking for signs of reionisation in nearby galaxies, they found evidence that dense hydrogen "fog" burned off first in isolated, low-density regions of the Universe and that reionisation took place in the dense, crowded regions of the Universe a few million years later.
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Blobrana


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Glow From The First Objects In The Universe
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 NASA's Spitzer Finds First Objects Burned Furiously

The faint, lumpy glow given off by the very first objects in the universe may have been detected with the best precision yet, using NASA's Spitzer Space Telescope. These faint objects might be wildly massive stars or voracious black holes. They are too far away to be seen individually, but Spitzer has captured new, convincing evidence of what appears to be the collective pattern of their infrared light.
The observations help confirm the first objects were numerous in quantity and furiously burned cosmic fuel.
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Blobrana


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ARCADE
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Title: A dark matter interpretation for the ARCADE excess?
Authors: N. Fornengo, R. Lineros, M. Regis, M. Taoso

The ARCADE 2 Collaboration has recently measured an isotropic radio emission which is significantly brighter than the expected contributions from known extra-galactic sources. The simplest explanation of such excess involves a "new" population of unresolved sources which become the most numerous at very low (observationally unreached) brightness. We investigate this scenario in terms of synchrotron radiation induced by WIMP annihilations or decays in extragalactic halos. Intriguingly, for light-mass WIMPs with thermal annihilation cross-section, and fairly conservative clustering assumptions, the level of expected radio emission matches the ARCADE observations.

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Blobrana


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RE: Glow From The First Stars In The Universe
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The remnants of a 13-billion-year-old star have been discovered by a team of researchers.
Cambridge professor of cosmology Max Pettini describes what the universe's "dark ages" were like.
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Blobrana


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The Dark Ages
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No place seems safe from the prying eyes of inquisitive astronomers.
They've traced the evolution of the universe back to the "Big Bang," the theoretical birth of the cosmos 13.7 billion years ago, but there's still a long stretch of time -- about 800 million years -- that's been hidden from view.
Astronomers call it the Dark Ages, and now they're building huge new radio telescopes with thousands of detectors that they hope will let them peer back into the period, when the first stars and galaxies began turning on their lights.

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Blobrana


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RE: Glow From The First Stars In The Universe
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Clearing of ancient fog remains mystery to astronomers
An international team of astronomers has discovered the oldest and most distant carbon in the Universe, but theres not enough of it to support standard theories of how the Universe lit up, a member from Swinburne University of Technology has calculated.
In the early Universe a dark pervasive fog of neutral hydrogen gas lurked everywhere. Astronomers think that this fog cleared when the first stars formed and emitted light.
There is a close connection between the amount of light and carbon produced in stars. But adding up all the 13-billion-year-old carbon detected, Dr Emma Ryan-Weber and her collaborators came to the conclusion the amount of carbon, and therefore the number of massive stars, was insufficient to lift the fog.
The observations of early carbon took place in collaboration with Prof. Piero Madau from the University of California at Santa Cruz, and Prof. Max Pettini and PhD student Berkeley Zych at Cambridge University in the UK. They used the European Southern Observatorys eight-metre Very Large Telescope in Chile as well as the 10-metre W.M. Keck Telescope in Hawaii. The results have recently been published in the Monthly Notices of the Royal Astronomical Society.

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Blobrana


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Nearly three years ago, an intrepid group of astronomers - including two UCSB researchers - lofted a giant helium balloon into the sky.
The balloon, borrowed from NASA, served as a platform for launching a probe into the Milky Way galaxy with the aim of collecting data samples of the heat that radiates from certain stars. What the scientists ended up discovering, however, was quite unexpected.
The researchers found that their ARCADE probe - an Absolute Radiometer for Cosmology, Astrophysics and Diffuse Emission - was prevented from completing its original mission due to the presence of a mysterious and powerful cosmic noise.

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Blobrana


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The impending digital-TV transition has a forgotten victim: the big bang. You can tune an analogue set between broadcast channels and see static, part of which is energy left over from the hot primordial universe. This static is known as the cosmic microwave background radiation, and its discovery in the 1960s proved the big bang theory. But on a digital TV, the best you can do is "The Big Bang Theory".
Last week at the American Astronomical Society's meeting, astronomers announced the detection of a second type of radio static from the heavens, and although it may not come from an era quite as ancient as TV snow does, it may probe the period immediately afterward - an equally mysterious time when the first stars and black holes were lighting up. That is, if the signal proves real.

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Blobrana


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Space is typically thought of as a very quiet place. But one team of astronomers has found a strange cosmic noise that booms six times louder than expected.
The roar is from the distant cosmos. Nobody knows what causes it.
Of course, sound waves can't travel in a vacuum (which is what most of space is), or at least they can't very efficiently. But radio waves can.

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Blobrana


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A balloon-borne experiment has turned up a mysterious radio signal that seems to be coming from beyond the Milky Way. Astronomers do not yet have a clear explanation for the static, but say it could come from the universe's first generation of stars.
The noise was found with a balloon-borne instrument called ARCADE, which flew for four hours at an altitude of 37 kilometres above Texas in July 2006. The instrument mapped a doughnut-shaped region that covered some 7% of the sky.
The team intended to look for slight deviations in the spectrum of the cosmic microwave background, the first radiation emitted after the big bang.
Instead, after subtracting known radio sources in the Milky Way and other galaxies, an unexplained radio static was left that seemed to pervade the sky and was some six times louder than all known astronomical sources combined at the same radio frequency.

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