The anisotropic x-ray diffuse scattering pattern surrounding this Bragg reflection from La1.8Sr2.2Mn2O7 at 125 K provides evidence that Jahn-Teller polarons (football-shaped lattice distortions that follow hopping electrons from site to site) play a role in this material's exotic phase transition from paramagnetic insulator to ferromagnetic metal. This data was used to perform a quantitative three-dimensional structural analysis of transient polaronic distortions.
This image from the BYU 0.9-m telescope looks out along the plane of our Milky Way Galaxy toward the constellation Cygnus the Swan. Called the Tulip Nebula, the glowing cloud of interstellar gas and dust is also listed in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. This nebula is about 8,000 light-years away from the solar system. The nebula shown here is a composite image that maps emission from sulfur, hydrogen, and oxygen atoms into red, green, and blue colors. Energy from the hot O-type star HDE 227018 ionizes atoms in this region so that we see a faint glow from the Tulip Nebula. HDE 227018 is seen near the blue arc at center of the image. This appeared as the NASA Astronomy Picture of the Day on July 26, 2012. Image Credit & Copyright: Michael Joner, David Laney (West Mountain Observatory, BYU); Processing - Robert Gendler
The laser intensity at the center of this laser focus is an astounding billion gigawatts (a billion billion watts) per square centimeter. This easily makes it most intense spot on campus. The laser pulse which creates the spot lasts only 30 femtoseconds, and is used to rip electrons from helium and study the radiation they emit in this intense field.
This photograph from university photographer, Mark Philbrick shows the BYU 0.9-meter Reflector at the West Mountain Observatory focused on a field near the galactic center during the summer of 2016. The stars of the constellation Scorpius are visible through the lower center portion of the dome slit with the planets Mars (on the right side) and Saturn (just off the left edge) visible. The computer controlled telescope was funded through an NSF grant; AST 0618209.
Group theory provides the most natural parameter set for describing a distorted crystal structure, since a relatively small number of parameters normally exhibit non-zero values. These symmetry modes are also the ideal parameter set for determining a complicated structural distortion and determining its symmetry without prior assumptions. This was demonstrated in a combined x-ray/neutron study of monoclinic room-temperature tungsten oxide.
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8 December, Thursday
9 December, Friday
Traci Neilsen, Kent Gee, and Blaine Harker et al. recently published an article titled "Level-educed Wavepacket Representation of Noise Radiation from a High-performance Military Aircraft" in 54th AIAA Aerospace Sciences Meeting (San Diego, CA, January 2016). . Click on the image above to read it.
: Not a comet, bright spiral galaxy Messier 51 is popularly known as the Whirlpool Galaxy. Just off the handle of the Big Dipper in northern skies, you can spot it at the upper left in this image from December 1st. The pretty 4 by 2.5 degree wide field of view does contain two comets though....
This photograph and Description come from NASA's Astronomy Picture of the Day web site.