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Posts Tagged ‘microwave radiation’

Rings And Loops In The Stars: Planck’s Stunning New Images


Credit: M. Peel / JCBA / Planck / ESA

Credit: M. Peel / JCBA / Planck / ESA

A ring of dust 200 light years across and a loop covering a third of the sky: two of the results in a new map from the Planck satellite. Dr Mike Peel and Dr Paddy Leahy of the Jodrell Bank Centre for Astrophysics (JCBA) presented the images today at the National Astronomy Meeting (NAM 2015) at Venue Cymru, Llandudno, Wales.

The European Space Agency (ESA) Planck satellite, launched in 2009 to study the ancient light of the Big Bang, has also given us maps of our own Galaxy, the Milky Way, in microwaves (radiation at cm- to mm-wavelengths). Microwaves are generated by electrons spiralling in the Galaxy’s magnetic field at nearly the speed of light (the synchrotron process); by collisions in interstellar plasma, by thermal vibration of interstellar dust grains, and by “anomalous” microwave emission (AME), which may be from spinning dust grains.

The relative strength of these processes changes with wavelength, and are separated using multi-wavelength measurements from Planck, from NASA’s WMAP satellite, and from ground-based radio telescopes, giving maps of each component.

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Radiation From Early Universe Found Key To Answer Major Questions In Physics


Astrophysicists at UC San Diego have measured the minute gravitational distortions in polarized radiation from the early universe and discovered that these ancient microwaves can provide an important cosmological test of Einstein’s theory of general relativity. These measurements have the potential to narrow down the estimates for the mass of ghostly subatomic particles known as neutrinos.

The radiation could even provide physicists with clues to another outstanding problem about our universe: how the invisible “dark matter” and “dark energy,” which has been undetectable through modern telescopes, may be distributed throughout the universe.

The scientists are publishing details of their achievement in the June issue of the journal Physical Review Letters, the most prestigious journal in physics, which highlighted their paper as an “editor’s suggestion” because of its importance and significance to the discipline.

The UC San Diego scientists measured variations in the polarization of microwaves emanating from the Cosmic Microwave Background—or CMB—of the early universe. Like polarized light (which vibrates in one direction and is produced by the scattering of visible light off the surface of the ocean, for example), the polarized “B-mode” microwaves the scientists discovered were produced when CMB radiation from the early universe scattered off electrons 380,000 years after the Big Bang, when the cosmos cooled enough to allow protons and electrons to combine into atoms.

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First Direct Evidence Of Inflation And Primordial Gravitational Waves


Credit: The BICEP2 Collaboration

Credit: The BICEP2 Collaboration

Astronomers announced today that they have acquired the first direct evidence that gravitational waves rippled through our infant universe during an explosive period of growth called inflation. This is the strongest confirmation yet of cosmic inflation theories, which say the universe expanded by 100 trillion trillion times in less than the blink of an eye.

“The implications for this detection stagger the mind,” says Jamie Bock, professor of physics at Caltech, laboratory senior research scientist at the Jet Propulsion Laboratory (JPL) and project co-leader. “We are measuring a signal that comes from the dawn of time.”

Our universe burst into existence in an event known as the Big Bang 13.8 billion years ago. Fractions of a second later, space itself ripped apart, expanding exponentially in an episode known as inflation. Telltale signs of this early chapter in our universe’s history are imprinted in the skies in a relic glow called the cosmic microwave background. Tiny fluctuations in this afterglow provide clues to conditions in the early universe.

Small, quantum fluctuations were amplified to enormous sizes by the inflationary expansion of the universe. This process created density waves that make small differences in temperature across the sky where the universe was denser, eventually condensing into galaxies and clusters of galaxies. But as theorized, inflation should also produce gravitational waves, ripples in space-time propagating throughout the universe. Observations from the BICEP2 telescope at the South Pole now demonstrate that gravitational waves were created in abundance during the early inflation of the universe.

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Last Command Sent To ESA’s Planck Space Telescope

October 25, 2013 Leave a comment

Credit: ESA and the Planck Collaboration - D. Ducros

Credit: ESA and the Planck Collaboration – D. Ducros

ESA’s Planck space telescope has been turned off after nearly 4.5 years soaking up the relic radiation from the Big Bang and studying the evolution of stars and galaxies throughout the Universe’s history.

Project scientist Jan Tauber sent the final command to the Planck satellite this afternoon at 12:10:27 UT, marking the end of operations for ESA’s ‘time machine’.

Launched in 2009, Planck was designed to tease out the faintest relic radiation from the Big Bang – the Cosmic Microwave Background (CMB). The CMB preserves a picture of the Universe as it was about 380 000 years after the Big Bang, and provides details of the initial conditions that led to the Universe we live in today.

“Planck has provided us with more insight into the evolution of the Universe than any mission has before,” says Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.

“Planck’s picture of the CMB is the most accurate ‘baby photo’ of the Universe yet, but the wealth of data still being scrutinised by our cosmologists will provide us with even more details.”

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Ultracold Big Bang Experiment Successfully Simulates Evolution Of Early Universe

August 29, 2013 Leave a comment

Physicists have reproduced a pattern resembling the cosmic microwave background radiation in a laboratory simulation of the Big Bang, using ultracold cesium atoms in a vacuum chamber at the University of Chicago.

“This is the first time an experiment like this has simulated the evolution of structure in the early universe,” said Cheng Chin, professor in physics. Chin and his associates reported their feat in the Aug. 1 edition of Science Express, and it will appear soon in the print edition of Science.

Full Story: http://news.uchicago.edu/article/2013/08/28/ultracold-big-bang-experiment-successfully-simulates-evolution-early-universe

A New Baby Picture Of The Universe


THIS SPRING, HUMANITY WAS SHOWN ITS MOST DETAILED MAP of the early universe ever created. Generated by observations from the Planck spacecraft, the map shows fluctuations in temperature in the relic radiation left over from the Big Bang – the moment when space and time came into existence nearly 14 billion years ago. That relic radiation, a kind of afterglow from the Big Bang, is called the cosmic microwave background, or CMB. It streams toward Earth from everywhere in the sky, and it provides a snapshot of what the universe looked like when the CMB was generated 380,000 years after the Big Bang.

Recently, scientists on the Planck team found certain large-scale features on the CMB sky, which they called “anomalies,” that they cannot explain. One of them, for example, is a large cold spot, which corresponds to an anomalously large area of high density. What this means: the theory for how the universe began may need to be modified, amended or even fundamentally changed. In any of these cases, the result will be consequential to how we understand the evolution of existence.

Full Story: http://www.kavlifoundation.org/science-spotlights/kicc-planck-universe

New Radio Telescope In SA Will Also Shed New Light On The Earliest Moments Of The Universe: C-BASS South Commissioning At Hartebeesthoek


In the week that saw the release of the first results from the European Space Agency’s Planck satellite, astronomers at the Hartebeesthoek Radio Astronomy Observatory (HartRAO) near Johannesburg are working on a new radio telescope that will also shed new light on the very earliest moments of the universe.

The C-Band All-Sky Survey (C-BASS) is a project to map the sky in microwave (short-wavelength radio) radiation. Like Planck, it will survey the whole sky, mapping out how bright the sky is, and also the orientation of the waves (called polarization). While Planck observes very short wavelengths, C-BASS observes longer wavelengths that are actually easier to observe from the ground.

“Because we want to observe at these longer wavelengths, the C-BASS telescope has to be much bigger than the telescope on Planck,” explains South African C-BASS team member Charles Copley. “The C-BASS dish is over seven metres across – much too big to launch on a rocket.”

In order to observe the entire sky, C-BASS needs to use two different telescopes, one in the northern hemisphere and one in the southern hemisphere.

Full Story: http://www.ska.ac.za/releases/20130327.php