10,979 research outputs found
Raster graphics extensions to the core system
A conceptual model of raster graphics systems was developed. The model integrates core-like graphics package concepts with contemporary raster display architectures. The conceptual model of raster graphics introduces multiple pixel matrices with associated index tables
Discovery and Cosmological Implications of SPT-CL J2106-5844, the Most Massive Known Cluster at z>1
Using the South Pole Telescope (SPT), we have discovered the most massive known galaxy cluster at z>1, SPT-CL J2106-5844. In addition to producing a strong Sunyaev-Zel'dovich (SZ) effect signal, this system is a luminous X-ray source and its numerous constituent galaxies display spatial and color clustering, all indicating the presence of a massive galaxy cluster. Very Large Telescope and Magellan spectroscopy of 18 member galaxies shows that the cluster is at z = 1.132^(+0.002)_(–0.003). Chandra observations obtained through a combined HRC-ACIS GTO program reveal an X-ray spectrum with an Fe K line redshifted by z = 1.18 ± 0.03. These redshifts are consistent with the galaxy colors found in optical, near-infrared, and mid-infrared imaging. SPT-CL J2106-5844 displays extreme X-ray properties for a cluster having a core-excluded temperature of T_X = 11.0^(+2.6)_(–1.9) keV and a luminosity (within r _(500)) of LX (0.5-2.0 keV) = (13.9 ± 1.0) × 10_(44) erg s^(–1). The combined mass estimate from measurements of the SZ effect and X-ray data is M_(200) = (1.27 ± 0.21) × 10^(15) h ^(–1) _(70) M_⊙. The discovery of such a massive gravitationally collapsed system at high redshift provides an interesting laboratory for galaxy formation and evolution, and is a probe of extreme perturbations of the primordial matter density field. We discuss the latter, determining that, under the assumption of ΛCDM cosmology with only Gaussian perturbations, there is only a 7% chance of finding a galaxy cluster similar to SPT-CL J2106-5844 in the 2500 deg^2 SPT survey region and that only one such galaxy cluster is expected in the entire sky
SSME structural dynamic model development
A mathematical model of the Space Shuttle Main Engine (SSME) as a complete assembly, with detailed emphasis on LOX and High Fuel Turbopumps is developed. The advantages of both complete engine dynamics, and high fidelity modeling are incorporated. Development of this model, some results, and projected applications are discussed
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Dust devils on Mars: Effects of surface roughness on particle threshold
Abstract not available
Letter from D. J. Foley to John Muir, [ca. 1899].
2of the church of England and had been located at Lompoc, Cal. They think him sort of queer . I told the story at the Hush residence in East Oakland (Tom Magee, Jr\u27s father-in law) a short time since and we all had a good laugh. But [for?] me, at the time, up on the side of that lonely and rocky mountain, miles from anyone, it was not, then, much of a joke. That was the only time in my life when I wanted a cannon . I would not have hurt him very much, but I would just like to have met his bluff with one, and then, if necessary, take off a toe, or finger or arm. But, as you remarked, at that glorious camp-fire and lecture, the little unpleasant02648 3events of such a trip will be forgotten and only the pleasant and preferable one will be remembered. Such is my case. By the way a party of R.R. surveyors commenced work at the Cascades, the latter part of Sept. and they should have completed their survey [of?] Meced ere this. There were [five?] [parties?], and they made a complete survey, so that contracts can be let, if they want it.Very Truly YsD.J. Fole
Optical-inertia space sextant for an advanced space navigation system, phase B
Optical-inertia space sextant for advanced space navigation syste
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