Physics Colloquium, "Picoastronomy: an electron microscopist's view of the history of the Solar System"
Presented by: Rhonda Stroud, U.S. Naval Research Laboratory
Abstract: A wide range of astrophysical processes, from condensation of dust particles in circumstellar envelopes to space weathering on airless bodies, are inherently pico-to-nanoscale phenomena. Thus, an electron microscope, used for direct observation of planetary materials in the laboratory, can be as much of an astronomical tool as a telescope pointed at the sky. The energy resolution of state-of-the-art monochromated scanning transmission electron microscopes (STEMs), as low as 10 meV, makes it possible to directly observe the infra-red optical properties of individual cosmic dust grains in the 2 to 25 um range. Thus, distinguishing the 10-um and 18-um features of individual bonafide astrosilicates is now possible. Furthermore, the spatial resolution and sensitivity of the STEM enables imaging and at spectroscopy at scales down to the single atom. Samples of nanomaterials from diverse classes of stars from red giants to supernovae, from asteroids and comets, and the surface of the Moon are all available for laboratory studies. Results of these studies can help aid in the understanding of the formation and evolution of solar systems, and even provide clues for advancing the development of technologically important materials, such as doped nanodiamonds, SiC and graphene.
Coffee, tea, and cookies will be available starting at 3:45 p.m., in DUAN G1B31.
Wednesday, September 12, 2018 at 4:00pm to 5:00pm
Duane Physics and Astrophysics, G1B20
2000 Colorado Avenue, Boulder, CO 80309
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