Bulletin of the American Physical Society
2006 Four Corners Section of the APS Fall Meeting
Friday–Saturday, October 6–7, 2006; Logan, Utah
Session B4: Astrophysics |
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Chair: Tom Tierney, Los Alamos National Laboratory Room: Eccles Conference Center Room 305 |
Friday, October 6, 2006 10:30AM - 10:42AM |
B4.00001: Laboratory Nuclear Astrophysics or The universe as seen from underground. John E. Ellsworth, Steven E. Jones, Shannon Walch, Matthew R. Nerdin Our sun emits 380 yottawatt, yet the nuclear reactant energies producing that power are very low (1 keV). These energies are so low, that replication of such reactions in the laboratory produce rates that are nearly impossible to detect. Unlike the historical efforts to understand stellar processes by extrapolating down from higher energy beam experiments, there are efforts to study reactions using low energy reactants. To do so requires specialized equipment and environments. The results indicate the need to understand the Coulomb screening effects of condensed matter in these processes. An explanation for heat production in planetary cores may also follow. [Preview Abstract] |
Friday, October 6, 2006 10:42AM - 10:54AM |
B4.00002: Low energy accelerator for studying laboratory nuclear astrophysics. Matthew R. Nerdin, John E. Ellsworth, Steven E. Jones We present progress on the development of research equipment to study laboratory nuclear astrophysics reactions by bombarding deuterided metallic targets with accelerated ions. This effort consists of constructing a low energy accelerator and the initial testing of specialized low-rate, neutron and charged-particle detectors. [Preview Abstract] |
Friday, October 6, 2006 10:54AM - 11:06AM |
B4.00003: Photoevaporation of Clustered Minihalos by Primordial Stars Joseph Smidt, Dan Whalen The first primordial stars to form in the universe were extremely luminous objects that heavily influenced subsequent star formation in their vicinity. We run 1D and 3D simulations of minihalo evaporation by a Pop III star to ascertain whether its radiation promotes or quenches star formation in the halo. Preliminary results will be presented. [Preview Abstract] |
Friday, October 6, 2006 11:06AM - 11:18AM |
B4.00004: Phase-space distribution of unbound dark matter near the Sun Moqbil Alenazi, Paolo Gondolo We resolve discrepancies in previous analyses of the flow of collisionless dark matter particles in the Sun's gravitational field. We determine the phase-space distribution of the flow both numerically, tracing particle trajectories back in time, and analytically, providing a simple correct relation between the velocity of particles at infinity and at the Earth. We use our results to produce sky maps of the distribution of arrival directions of dark matter particles on Earth at various times of the year. We assume various Maxwellian velocity distributions at infinity describing the standard dark halo and streams of dark matter. We illustrate the formation of a ring, analogous to the Einstein ring, when the Earth is directly downstream of the Sun. [Preview Abstract] |
Friday, October 6, 2006 11:18AM - 11:30AM |
B4.00005: Characterizing lasers for cosmic ray ``test beams" at the Pierre Auger Observatory Shoji Komatsu, Lawrence Wiencke, Miguel Mostafa The Pierre Auger Observatory located in western Argentina is studying extended air-shower produced by high energy cosmic rays using two detectors: a Fluorescence Detector and a Surface Detector. Because cosmic rays test beams are unavailable, laser test beams are used to measure properties of Fluorescence Detector. Optical signatures of extended air-shower and laser test beams have several similarities. This talk will discuss characterization of the laser test beams including polarization and their absolute photometric calibration. [Preview Abstract] |
Friday, October 6, 2006 11:30AM - 11:42AM |
B4.00006: Surveying the TeV Sky with Milagro Gary Walker A wide field of view, high duty factor TeV gamma-ray observatory is essential for studying TeV astrophysical sources, because most of these sources are either highly variable or are extended. Milagro is such a TeV detector and has performed the deepest survey of the Northern hemisphere sky. In addition to detecting the Crab Nebula and Mrk 421, which are known TeV sources, Milagro has made the first detection of diffuse TeV emission from the Galactic plane. In addition, Milagro has discovered a new, extended source in the Galactic plane that is coincident with an EGRET unidentified source. Based on the success of Milagro, a second generation water Cherenkov gamma-ray observatory is planned which will give an increase in sensitivity of more than an order of magnitude. [Preview Abstract] |
Friday, October 6, 2006 11:42AM - 11:54AM |
B4.00007: Monocular spectrum and the search for exotic events in the ultra high energy cosmic ray data of HiRes (The High Resolution Fly's Eye). Douglas Rodriguez The High Resolution Fly's Eye (HiRes) experiment consists of two fluorescence detectors in search of the highest energy cosmic rays. These extremely energetic events can have 100 million times more energy than the highest energy achievable at man-made accelerators. The original Fly's Eye experiment observed one event with energy of 3.2 x 10$^{20}$ eV. When such cosmic rays arrive at the Earth, they interact with the nitrogen and other gases of the upper atmosphere, generating a shower of secondary particles which in turn produce ultra-violet fluorescence light that can be viewed by our detectors. The data, collected between 5/1997 and 4/2006, has been analyzed in both monocular and stereo formats to study the energy spectrum above 10$^{17.5}$ eV, incident particle composition, and source direction (anisotropy). I am analyzing the data from one HiRes site, HiRes-1, to produce a final monocular energy spectrum and to look for exotic events, particularly double showers. These are showers that could originate from one primary particle, but appear to the detectors as two separate coincident tracks. I will present this work as well as other uses for these analysis programs. [Preview Abstract] |
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