Cosmic Radio Background

[Buffy]

I caught this in the January 9, 2009 issue of The Economist, and I'm not sure where else it's been covered, but apparently an analog to the Cosmic Microwave Background has been discovered in the Radio frequency range....

Michael Seiffert ...at the Jet Propulsion Laboratory in Pasadena, California, and Alan Kogut at the Goddard Space Flight Centre in Maryland...had planned to test...[whether] the first stars to form after the Big Bang would have left some signs of themselves in the form of radio waves. Their experiment was designed to find these signs. Their search used radio telescopes launched to the edge of the atmosphere on special balloons from a site in Palestine, Texas. The result they got was not, however, what they were looking for.

 

The microwave background is the earliest snapshot of the universe, taken a mere 300,000 years after the Big Bang and almost 700,000 years before the first stars are thought to have coalesced. It reveals the newborn universe to have been a remarkably uniform fireball. Dr Seiffert and Dr Kogut wanted to identify the point at which things stopped being so smooth and the universe started to develop the structures—galaxies, stars, planets and dust—that fill it today. It was for this reason that they were searching for signs of stars.

 

What they found, however, was a background hiss of radio noise, reminiscent of the hiss noticed by Dr Penzias and Dr Wilson. After ruling out nearby sources of radio waves, they concluded that their own hiss also comes from beyond the Milky Way and thus constitutes a cosmic radio background. Four papers describing the telescopes, the observations and their possible interpretation have been submitted to the Astrophysical Journal.

 

Why a cosmic radio background should be there remains a mystery. It does not appear to be coming from the primordial stars sought by the astronomers—indeed, it completely drowns out any signs of the early stars that were the object of the original quest. Nor are there enough radio galaxies around to account for it. It looks, therefore, like the sign of a previously unknown phenomenon.

(Gosh I love The Economist's article titles! )

 

This of course sounds quite fascinating and I thought I'd open a thread on it.

 

Anyone heard anything about this?

 

Good evening. Tonight we offer you a generous portion of mystery, a pinch of comedy, just a soupcon of a commercial, all seasoned by a few irrelevant comments from your host. As you may know, food is a hobby of mine. I don't claim to be an expert cook, but I am rather a good eater. If you will wander into my kitchen, I'll allow you to watch me as I concoct some delicacy to tempt your palate, :phones:

Buffy

[CraigD]

I caught this in the January 9, 2009 issue of The Economist, and I'm not sure where else it's been covered, but apparently an analog to the Cosmic Microwave Background has been discovered in the Radio frequency range.

...

Anyone heard anything about this?

First I have.

 

Seiffert et. al’s paper looks to be pretty new, not yet submitted for publishing, with a preprint last draft date of 1/21/09. It’s arxiv preprint PDF is here.

 

At a glance, this looks to me like “weird radioastronomy”. The summary description in its abstract – power law (ie: black body) emission at 1.06±0.11 K with spectral index (essentially a measure of how “flat”, on average, the graph of the frequencies of a sources emission are) of -2.56±0.04 – is far from any ordinary values in my experience, being extraordinarily cool and peaky where a typical star would have a spectral index of -0.1, and a very peaky source, like a x-ray source, will be in the vicinity of -1. It’s unusual, and beyond my amateur’s comprehension.

:phones:

I’m inclined to wait for comments from pro radioastronomers. There are a lot of possible interpretations of this paper, including the possibility that it’s an instrument relic (ie: not really there). Peer review is good, and I, alas, am far from a peer.