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Dark Matter Fisticuffs I: The Backdrop

November 21, 2010 By

The large scale structure of the Universe, as predicted in the Millennium simulations (V. Springel)

ResearchBlogging.orgOn Thursday, two giants of astronomy met in the sleepy German city of Bonn to debate one of the basic tenets of our current cosmological vision: the existence of dark matter. In the blue corner was Simon White aka. the Reigning Champion, Director at the Max Planck Insitute for Astrophysics (MPA) in Garching, and figurehead of the concordance cosmology model we all know and live by. In the red corner, Pavel Kroupa aka. the Challenger, Professor at the Argelander Institute in Bonn and well-known expert on stellar populations and dynamics.

Astronomers in Bonn live-blogged the event, and have given me permission to re-post their words on here – see Part II. But I thought I’d get you up to speed first.

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First light for Planck

September 18, 2009 By

First images from Planck, overlaid on an optical image of the galactic plane

The European Space Agency yesterday released first light images from its cosmic microwave background experiment, Planck. Planck was launched together with infrared observatory Herschel in May, and these first data show that the little satellite is in excellent working order.

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More dark chatter

February 9, 2009 By

While Mars and exoplanets stole most of the science headlines in 2008, papers reporting results from a number of cosmic ray detectors gathered a lot of attention in the (astro-)physics community. Excesses in the number of particles detected at high energies (~50 GeV) that could not be explained by theoretical predictions sparked speculations that cosmic ray satellite PAMELA may be picking up the signature of dark matter in the Galaxy. A commonly accepted scenario for the nature of dark matter are the so-called WIMPs, or weakly interacting massive particles, which don’t interact in “regular” processes but may annihilate each other to produce high energy cosmic radiation. A number of cosmic ray and gamma ray detectors have produced intriguing results, leaving scientists with an intricate puzzle of information to assemble into a coherent picture.

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An Early Universe 101

December 23, 2008 By

I’ve been learning a bit recently about dark matter, dark energy and the history of the Universe, which are all fascinating. Mark over on Cosmic Variance has writted this interesting post on preheating in the early Universe. This proposed phenomenon has important consequences for the formation theory of dark matter, amongst other things.

While I’m on the topic, one of the best books I read this year was The Inflationary Universe by Alan Guth. I admit I don’t read as many popular science books as I should, and I finish even fewer – but this one is a cracker. Guth builds an excellent story about how he arrived at the theory, in collaboration and in conflict with other scientists around the world. It’s a fascinating account of a great scientific discovery, told in such an anecdotal style that it’s super easy to read. It’s completely rekindled my interest in fundamental physics and cosmology, which explains some recent posts (here, or here) on the topic :-)

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‘Arrested development’ at work in the Universe

December 17, 2008 By

Left: Composite image of galaxy cluster Abell 85, using X-ray data (purple) from Chandra and optical image from the Sloan Digistal Sky Survey. Right: Snapshots of the Universe's evolution from a simulation by Volker Springel of MPA, at 0.9, 3.2 and 13.7 billion years.

A cross-continental team of astronomers led by Andrei Vikhlinin have used data from the American X-ray space telescope Chandra to help pin down the nature of the most enigmatic stuff in the Universe, dark energy. By observing clusters of galaxies over a range of different ages, the team were able to track how their masses have evolved over the history of the Universe. Using the statistics of this evolution and comparing them with results from several other complimentary studies, they have significantly narrowed the constraints on the precise nature of dark energy.

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