7,603 research outputs found

    ATD-2 Integrated Arrival/Departure/Surface (IADS) System Specification - Phase 2

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    The purpose of this document is to capture the core capabilities developed in ATD-2 Phase 2

    The happiness - suicide paradox

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    Suicide is an important scientific phenomenon. Yet its causes remain poorly understood. This study documents a paradox: the happiest places have the highest suicide rates. The study combines findings from two large and rich individual-level data sets—one on life satisfaction and another on suicide deaths—to establish the paradox in a consistent way across U.S. states. It replicates the finding in data on Western industrialized nations and checks that the paradox is not an artifact of population composition or confounding factors. The study concludes with the conjecture that people may find it particularly painful to be unhappy in a happy place, so that the decision to commit suicide is influenced by relative comparisons.Happiness ; Suicide

    Radio Cores in Low-Luminosity AGN: ADAFs or Jets?

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    We have surveyed two large samples of nearby low-luminosity AGN with the VLA to search for flat-spectrum radio cores, similar to Sgr A* in the Galactic Center. Roughly one third of all galaxies are detected (roughly one half if HII transition objects are excluded from the sample), many of which have compact radio cores. Follow-up observations with the VLBA have confirmed that these cores are non-thermal in origin, with lower limits for the brightness temperatures around ~10^8 K. The brightest of these are resolved into linear structures. The radio spectral indices of the cores are quite flat (alpha~0), with no evidence for the highly inverted radio cores predicted in the ADAF model. Spectrum and morphology of the compact radio emission is typical for radio jets seen also in more luminous AGN. The emission-line luminosity seems to be correlated with the radio core flux. Together with the VLBI observations this suggests that optical and radio emission in at least half the low-luminosity Seyferts and LINERs are black hole powered. We find only a weak correlation between bulge luminosity and radio flux and an apparently different efficiency between elliptical and spiral galaxies for producing radio emission at a given optical luminosity.Comment: 5 pages, 2 figures, (ESO) LaTex, to appear in ``Black Holes in Binaries and Galactic Nuclei'', ESO workshop, eds. L. Kaper, E.P.J. van den Heuvel, P.A. Woudt, Springer Verlag; also available at http://www.mpifr-bonn.mpg.de/staff/hfalcke/publications.html#eso9
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