1,207 research outputs found

    Discovery of an Apparent High Latitude Galactic Supernova Remnant

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    Deep Hα\alpha images of a faint emission complex 4.0 x 5.5 degrees in angular extent and located far off the Galactic plane at l = 70.0 degrees, b=-21.5 degrees reveal numerous thin filaments suggestive of a supernova remnant's shock emission. Low dispersion optical spectra covering the wavelength range 4500 - 7500 A show only Balmer line emissions for one filament while three others show a Balmer dominated spectrum along with weak [N I] 5198, 5200 A, [O I] 6300, 6364 A, [N II] 6583 A, [S II] 6716, 6731 A and in one case [O III] 5007 A line emission. Many of the brighter Hα\alpha filaments are visible in near UV GALEX images presumably due to C III] 1909 A line emission. ROSAT All Sky Survey images of this region show a faint crescent shaped X-ray emission nebula coincident with the portion of the Hα\alpha nebulosity closest to the Galactic plane. The presence of long, thin Balmer dominated emission filaments with associated UV emission and coincident X-ray emission suggests this nebula is a high latitude Galactic supernova remnant despite a lack of known associated nonthermal radio emission. Relative line intensities of the optical lines in some filaments differ from commonly observed [S II]/Hα\alpha > 0.4 radiative shocked filaments and typical Balmer filaments in supernova remnants. We discuss possible causes for the unusual optical SNR spectra.Comment: 12 pages, 10 figures, accepted to the Astrophysical Journa

    Solstice

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    The Shape of the Winnow

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    Enterprise Smart Outlet: Android Development

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    This project consists of one part of a larger multidisciplinary project, Enterprise Smart Outlet. The purpose of the Enterprise Smart Outlet is to create an electrical outlet which would allow enterprise users to monitor and change their power consumption habits on a large scale. The goal of this project is to allow consumers to see their power consumption per outlet in real time, and then use that information to inform their future habits, helping them conserve electrical energy and money. The Enterprise Smart Outlet Android application provides an interface to display the real time data of all smart outlets connected and the ability to enable or disable each outlet individually

    Differentiation in impact melt sheets as a mechanism to produce evolved magmas on Mars

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    Asteroid bombardment contributed to extensive melting and resurfacing of ancient (\u3e 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na2O + K2O) and silica (up to 67 wt% SiO2) with low (\u3c 5wt%) MgO. This alkaline differentiation trend has previously been attributed to fractional crystallization of magmas resulting from low-degree mantle melting analogous to ocean island or rift settings on Earth. In this study, we investigate the hypothesis that differentiation of impact-generated melts provides a viable alternative explanation for the petrogenesis of some evolved rocks on Mars. We scaled melt volumes and melt sheet thicknesses for a range of large impact magnitudes and employed the MELTS algorithm to model mineral phase equilibria in those impact-generated melts. Model runs consider a range of possible oxidation states (IW to QFM), crystallization regimes (batch, fractional and liquid segregation), and volatile contents (initially water-saturated and nominally anhydrous). Moderate pressure and water are required to produce alkaline differentiation trends in mafic melts. Large impacts that melt a water-bearing early basaltic crust provide a mechanism to generate wetter magmas on Mars, consistent with some observed Martian differentiation trends. Low-degree partial melting and/or an alkali-enriched source are required to generate the most alkaline observed compositions, motivating future work to examine partial melting regimes during large impacts

    Inequality in Real Property Tax Review

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    Solstice

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    The Speedy Trial Act: Conflict among the Circuits

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    The Speedy Trial Act: Conflict among the Circuits

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