SLAC Today is
available online at:
http://today.slac.stanford.edu
In this issue:
Gamma-ray Bursts Active Longer Than Thought
Profile: Manuel Hipol - Healer, Surfer
New Mandatory Course for Supervisors
Seminar to Demystify Estate Planning
Wednesday - May 23, 2007 |
Gamma-ray Bursts Active Longer Than ThoughtUsing NASA's Swift satellite, astronomers have discovered that energetic flares seen after gamma-ray bursts (GRBs) are not just hiccups, they appear to be a continuation of the burst itself. GRBs release in seconds the same amount of energy our Sun will emit over its expected 10 billion-year lifetime. The staggering energy of a long-duration GRB (lasting more than a few seconds) comes from the core of a massive star collapsing to form a black hole or neutron star. In current theory, inrushing gas forms a disk around the central object. Magnetic fields channel some of that material into two jets moving at near-light speed. Collisions between shells of ejected material within the jet trigger the actual GRB. Early in the mission, Swift's X-ray Telescope (XRT) discovered that the initial pulse of gamma-rays, known as prompt emission, is often followed minutes to hours later by short-lived but powerful X-ray flares. The flares suggested—but did not prove—that GRB central engines remain active long after the prompt emission. After analyzing GRB 060714, named for its detection date of July 14, 2006, Jonathan Granot of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) and eight colleagues, have demonstrated that x-ray flares are indeed a continuation of the prompt emission, showing that GRB central engines are active much longer than previously thought. Read more... |
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Manuel Hipol:
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New Mandatory ES&H Course for SupervisorsIn the coming weeks, the Environment, Safety and Health (ES&H) Division will present six sessions of Course 418, "ES&H Management for Supervisors." This course contains new content and is mandatory for all supervisors. It will automatically be added to the SLAC Training Assessment of each supervisor.
The training will:
Training will be offered as follows: All supervisors will soon receive an email as a reminder of this training requirement. ES&H Coordinators at all levels are encouraged to attend. Direct any questions to Brian Sherin (x5082) or Robin Wendt (x4295). Seminar to Demystify Estate PlanningFind out what's fact and what's fiction in the world of estate planning this afternoon at 12 noon in the Kavli Auditorium. There, Attorney Hollis L. Logue, III, will present the WIS seminar "Personal Wealth Preservation Strategies." One of the most informative and entertaining speakers in the Bay Area, Logue is an attorney whose law practice is devoted to helping families control, protect, and preserve their assets. In today's seminar, he will explain:
- How a house can be a hidden |
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