For the first time, scientists from UC Berkeley and Lawrence Livermore, in conjunction with astrophysicists from the California Institute of Technology, UC Santa Cruz, the National Science Foundations Center for Adaptive Optics and UCs Lick Observatory, have observed that distant larger stars formed in flattened accretion disks just like the sun.
The Lick Observatory Laser Guide Star Adaptive Optics system in operation on July 22, 2003.The laser beam is visible for several kilometers. The yellowish cast of the dome is due to the street lights of nearby San Jose.
Using the laser guide star adaptive optics system created by LLNL scientists, the team was able to determine that some of the relatively young yet massive Herbig Ae/Be stars contain biconical nebulae, polarized jets and circumstellar disks. Less massive stars including the sun are believed to be formed in a swirling spherical cloud that collapses into a disk.
The astronomers observed a strongly polarized, biconical nebula 10 arcseconds in diameter around the star LkHa 198 and a polarized jet-like feature in LkHa 198-IR. The star LkHa 233 featured a narrow, unpolarized dark lane similar to an optically thick circumstellar disk. The research appears in the Feb. 27 edition of the journal Science.
Anne Stark | LLNL
Underlying mechanism discovered for magnetic effect in superconducting spintronics
11.07.2018 | American Institute of Physics
PPPL diagnostic is key to world record of German fusion experiment
10.07.2018 | DOE/Princeton Plasma Physics Laboratory
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
Sizes and shapes of nuclei with more than 100 protons were so far experimentally inaccessible. Laser spectroscopy is an established technique in measuring fundamental properties of exotic atoms and their nuclei. For the first time, this technique was now extended to precisely measure the optical excitation of atomic levels in the atomic shell of three isotopes of the heavy element nobelium, which contain 102 protons in their nuclei and do not occur naturally. This was reported by an international team lead by scientists from GSI Helmholtzzentrum für Schwerionenforschung.
Nuclei of heavy elements can be produced at minute quantities of a few atoms per second in fusion reactions using powerful particle accelerators. The obtained...
A team headed by the TUM physicists Alexander Holleitner and Reinhard Kienberger has succeeded for the first time in generating ultrashort electric pulses on a chip using metal antennas only a few nanometers in size, then running the signals a few millimeters above the surface and reading them in again a controlled manner. The technology enables the development of new, powerful terahertz components.
Classical electronics allows frequencies up to around 100 gigahertz. Optoelectronics uses electromagnetic phenomena starting at 10 terahertz. This range in...
03.07.2018 | Event News
28.06.2018 | Event News
28.06.2018 | Event News
11.07.2018 | Information Technology
11.07.2018 | Physics and Astronomy
11.07.2018 | Materials Sciences