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Students of Gaston Gutierrez never forget him. Two of his former students, Florencia Canelli and Juan Estrada, still apply the lessons that they learned from their mentor several years ago on the DZero collider experiment at the Department of Energy’s Fermi National Accelerator Laboratory. “Juan and I worked very closely with Gaston. Even now, when faced with a difficult problem, we try to imagine how Gaston would solve it,” said Canelli, now a physicist with a joint appointment between Fermilab and the University of Chicago. As a result of his contributions to the DZero experiment and his dedication to mentoring young scientists, Fermilab’s Gutierrez received the 2009 Edward A. Bouchet Award from the American Physical Society. When Gutierrez joined the DZero collaboration in 1997, his first project was to build the central fiber tracker, one of four major parts at the heart of the DZero particle detector. When he wasn’t constructing the tracker, he developed a new analysis technique to measure the mass of the top quark. “I like to work on both construction and analysis,” Gutierrez said. “Ideally you build it, and then you use it.” Canelli and Estrada were both graduate students at the University of Rochester when they started working with Gutierrez at Fermilab. With their home institution 650 miles away, Gutierrez took them under his wing and collaborated with their advisor, Tom Ferbel. “Florencia and Juan both have strong careers now,” said Ferbel. “A lot of that was triggered by their work with Gaston.” Both Canelli and Estrada have won awards for their research on the mass of the top quark, attesting to the positive impact that Gutierrez had on their developing careers. “Working with Gaston is the best thing that ever happened to me,” said Estrada. “I’m not a student any more, but I still like to work with him because I know that everything will come out perfectly.”Submitted by DOE's Fermi National Accelerator Laboratory |
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Check out the joint Fermilab/SLAC publication symmetry.
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Pulsar observation opens new
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| Clouds of charged particles move along the pulsar's magnetic field lines (blue) and create a lighthouse-like beam of gamma rays (purple) in this illustration. (Image courtesy of NASA.) |
About three times a second, a 10,000-year-old stellar corpse sweeps a beam of gamma-rays toward Earth. This object, known as a pulsar, is the first one known to "blink" only in gamma rays, and was discovered by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope, a collaboration between NASA, DOE and international partners.
The LAT data, which was processed by DOE's SLAC National Accelerator Laboratory and analyzed by the international LAT collaboration, shows that the gamma-ray-only pulsar's lighthouse-like beam sweeps Earth's way every 316.86 milliseconds and emits 1,000 times the energy of our sun.
A pulsar is a rapidly spinning neutron star, the crushed core left behind when a massive sun explodes. Although most pulsars are known to emit at radio wavelengths, some of these objects also beam energy in other forms, including visible light and X-rays.
Unlike previously discovered pulsars, the newly-observed pulsar appears to blink only in gamma-ray energies, offering researchers a new way to study the stars in our universe.
The LAT sees about one gamma ray each minute from the gamma-ray-only pulsar. That's enough for scientists to piece together the pulsar's pulsing period, its rotation period, and the rate at which it's slowing down. These measurements are also vital to understanding the dynamics of a pulsar's behavior and can be used to estimate the pulsar's age. From the slowing period, researchers have determined that the pulsar is actually powering all the activity in the nebula where it resides.
These results appear in the Oct. 16 edition of Science Express.
Submitted by DOE's SLAC National Accelerator Laboratory