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In this issue:
Simulations Illuminate Universe's First Twin Stars
Save the Date: Annual LCLS/SSRL Users' Meeting and Workshops
June 2009 Issue of Symmetry Online

SLAC Today

Monday - July 13, 2009

Simulations Illuminate Universe's First Twin Stars

(Image - binary star simulation)
This computer-simulated image shows the formation of two high density regions (yellow) in the early universe, approximately 200 million years after the Big Bang. The cores are separated by about 800 times the distance between the Earth and the Sun, and are expected to evolve into a binary—or "twin"—star system. (Image and simulation courtesy of Ralf Kaehler, Matthew Turk and Tom Abel.)

The earliest stars in the universe formed not only as individuals, but sometimes also as twins, according to a paper published today in Science Express. By creating robust simulations of the early universe, astrophysicists Matthew Turk and Tom Abel of the Kavli Institute for Particle Astrophysics and Cosmology and Brian O'Shea of Michigan State University have gained the most detailed understanding to date of the formation of the first stars.

"We used to think that these stars formed by themselves, but now we see from our computer simulations that sometimes they have siblings," said Turk. "These stars provide the seeds of next generation star formation, so by understanding them we can better understand how other stars and galaxies formed."

To make this discovery, the researchers created an extremely detailed computer simulation of early star formation. Into this virtual universe they sprinkled primordial gas and dark matter as it existed soon after the Big Bang, data they obtained from observations of the cosmic microwave background. This mostly uniform radiation—a faint glow of radio waves spread across the entire sky—contains subtle variations that reflect the beginning of all structure in the universe.  Read more and see video of the simulation...

Save the Date: Annual LCLS/SSRL Users' Meeting and Workshops

(Image - LCLS/SSRL Users' Meeting banner)

The Annual SSRL/LCLS Users' Meeting and Workshops will run October 18–21. On the 18th, a special symposium honoring the Stanford Synchrotron Radiation Lightsource's 35th anniversary will discuss the facility's many accomplishments and look toward the scientific and technical opportunities in its future. The next three days will include plenary and parallel sessions featuring a variety of presentations on SSRL and LCLS instrumentation, techniques, developments and user research. The event will also give members of the LCLS and SSRL communities the opportunity to interact with other scientists, potential colleagues and vendors of light source related products and services. For further information, please see the event Web site or contact Cathy Knotts.

(Image - Symmetry magazine cover June 2009)

June 2009 Issue of Symmetry Online

This issue features people building a Dark Energy Camera, recycling helium, fostering diversity at national labs, encouraging fellow scientists to Twitter,  and admiring the accidental beauty of ordinary test samples. The mayor of a small Colorado mining town talks about its future as the site of a major underground lab. We stick a few pins in the Periodic Table to mark the elements most essential to particle physics, examine an early sketch for Pierre Auger Observatory, and explain virtual particles in less time than it takes to brush your teeth (provided you’re doing as thorough a job as your dentist advises! ‘Fess up, now: Have you flossed?) Plus, as always,  short pieces on topics ranging from UFO rumors to cute little eco-mobiles, as well as highlights from Symmetry Breaking.

You’ll find the full Table of Contents here.


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