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Cosmic Radio Noise Booms Six Times Louder Than Expected

The balloon-borne ARCADE instrument discovered this cosmic static (white band, top) on its July 2006 flight. The noise is six times louder than expected. Astronomers have no idea why. Credit: NASA/ARCADE/Roen Kelly

The balloon-borne ARCADE instrument discovered this cosmic static (white band, top) on its July 2006 flight. The noise is six times louder than expected. Astronomers have no idea why. Credit: NASA/ARCADE/Roen Kelly



Loud sounds tend to startle us. But imagine being surprised by a sound six times louder than you expect. A balloon-borne instrument called ARCADE, (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission) was supposed to be used to search for heat signature from the first stars to form after the Big Bang. Instead it found an unexplained “booming” radio static that fills the sky.

In July 2006, the instrument launched from NASA’s Columbia Scientific Balloon Facility in Palestine, Texas, and flew to an altitude of 36,000 meters (120,000 feet) where the atmosphere thins into the vacuum of space. Its mission lasted four hours.

The team, led by Alan Kogut of NASA’s Goddard Space Flight Center said they found the radio noise almost immediately. “We were calibrating the instrument, and we saw this big point in the graph. I said, ‘What the heck is this — this shouldn’t be here.’ We spent the next year trying to make that point go away, but it didn’t.”

shows the extragalactic temperature measured by ARCADE from the 2006 flight

shows the extragalactic temperature measured by ARCADE from the 2006 flight


Detailed analysis has ruled out an origin from primordial stars, user error or a mis-identified galactic emission, and the scientists are sure there aren’t more radio sources than we expect. “Radio source counts are well known and they don’t even come close to making up the detected background,” said Kogut. “New sources, too faint to observe directly would have to vastly outnumber the number everything else in the sky.”

Dale Fixsen of the University of Maryland at College Park, added that to get the signal they detected, radio galaxies would have to be packed “into the universe like sardines,” he said. “There wouldn’t be any space left between one galaxy and the next.”

The sought-for signal from the earliest stars remains hidden behind the newly detected cosmic radio background. This noise complicates efforts to detect the very first stars, which are thought to have formed about 13 billion years ago — not long, in cosmic terms, after the Big Bang. Nevertheless, this cosmic static may provide important clues to the development of galaxies when the universe was less than half its present age. Unlocking its origins should provide new insight into the development of radio sources in the early universe.

“This is what makes science so exciting,” says Michael Seiffert, a team member at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “You start out on a path to measure something — in this case, the heat from the very first stars — but run into something else entirely, something unexplained.”

ARCADE launches on its July 2006 discovery flight from NASA's Columbia Scientific Balloon Facility in Palestine, Texas. The balloon lofted the instrument to its observation altitude of 120,000 feet. Credit: NASA/ARCADE

ARCADE launches on its July 2006 discovery flight from NASA's Columbia Scientific Balloon Facility in Palestine, Texas. The balloon lofted the instrument to its observation altitude of 120,000 feet. Credit: NASA/ARCADE


ARCADE’s revolutionary design makes it super-sensitive to cosmic noise. Chilled to 2.7 degrees above absolute zero by immersion into more than 500 gallons of liquid helium, each of ARCADE’s seven radiometers alternately views the sky and a calibration target. The project allows for significant high school and undergraduate student participation. ARCADE is the first instrument to measure the radio sky with enough precision to detect this mysterious signal.

This is the same temperature as the cosmic microwave background (CMB) radiation, the remnant heat of the Big Bang that was itself discovered as cosmic radio noise in 1965. “If ARCADE is the same temperature as the microwave background, then the instrument’s heat cannot contaminate the cosmic signal,” Kogut explains.

“We don’t really know what this signal is,” said Seiffert. “We’re relying on our colleagues to to study the data and put forth some new theories.”

Source: NASA, AAS Press Conference

About 

Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

Comments on this entry are closed.

  • fats mcgoo IV January 10, 2009, 12:21 PM

    10xcsn, The new super-nova do-daah.
    Whats a macall it. Built by the aliens of Beta-Centari.
    Portuus the super grey alien is hitting a noober ball with his
    Jack over sticks.
    Gaaaapoo.
    Thanks hello, good-bye please and turn off the ice creme machine in Beta-Centari

  • fats mcgoo IV January 10, 2009, 12:22 PM

    Oh, and have a MERRY WEB BOT CHRISTMAS.
    From Portuus….the super-grey alien

  • Tjips January 11, 2009, 3:08 PM

    Firstly, “the noise was six times louder than expected” implies that the measurement in question had never been made before (probably not at that sensitivity). It doesn’t imply that the boom is very loud, only that it is six times louder than expected. Same that a carbon atom is bigger than a hydrogen atom while at the same time still being small.

    BTW I like the hitchhiker’s guide reference (Disaster area) :)

    Also, just for accuracy Dark Matter isn’t matter as we are used to thinking of matter i.e. it isn’t made up of protons, neutrons and electrons, it is made up of something entirely different (proof of this comes from measurements of Deuterium abundance in the universe). This doesn’t mean that it can’t be the source of the boom, but it does mean it isn’t necessarily compliant to E=mc^2.

    For some good insights into the what’s and how’s of dark matter and dark energy, check out Astronomy Today (The book, not a website). It puts things in perspective.

  • Vanamonde January 11, 2009, 8:50 PM

    So there may have been a time when young galaxies were all so close, they touch.

    And later, we find massive black holes seem to pre-exist before galaxies…

    Maybe source is the first generation of galactic seeding black holes being formed?

  • besidomentis January 12, 2009, 2:34 PM

    Well this picture shows that amazing thinks happining in center of our galaxy: http://www.part.lt/p-19f3ec3eb0570503c5022a66ca47ce35649.bmp

  • Liquid Memory January 13, 2009, 11:11 AM

    Why don’t we just take it for what it is? It is a sound 6 times greater than we have ever discovered. What my question is?

    Could it be the Horn of Gabriel?

  • Raven January 13, 2009, 8:44 PM

    I thought this was a serious topic? Also, it’s not really a “sound” as sound doesn’t travel well in space. It’s the detection of radio waves which represent a “boom”. However, I think my theory might be possible. I’d just like an experts take on it.

  • Mem(Brain) January 14, 2009, 3:09 AM

    I think death nears.

  • Jomark Osabel January 26, 2009, 11:10 PM

    Or perhaps some life forms in other galaxy are having a big party with big boom box

  • timmay January 31, 2009, 2:45 AM

    “Why don’t we just take it for what it is? It is a sound 6 times greater than we have ever discovered. What my question is?

    Could it be the Horn of Gabriel?”

    Answer: Umm…no.

    Its a frequency. Very pervasive.
    Could be the ‘noise’ made by supermassive
    black holes?
    Early galaxies birthing sound?

    Or just a really big P.A. somewhere?

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