11,382,379 research outputs found

    The third transit of snow-line exoplanet Kepler-421b

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    The Kepler Mission has uncovered a handful of long-period transiting exoplanets that orbit from the cold outer reaches of their systems, despite their low transit probabilities. The atmospheres of these cold gas giant exoplanets are amenable to transit transmission spectroscopy enabling tests of planetary formation and evolution theories. Of particular scientific interest is Kepler-421b, a Neptune-sized exoplanet with a 704-day orbital period residing near the snow-line. Since the Kepler Spacecraft only observed two transits of Kepler-421b, the transit ephemeris is relatively uncertain. We observed Kepler-421 during the anticipated third transit of Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Barring significant TTVs, our visible light, time-series observations from the 4.3-meter Discovery Channel Telescope (DCT) were designed to capture pre-transit baseline and the partial transit of Kepler-421b. We find strong evidence in favor of transit models with no TTVs, suggesting that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the combined Kepler and DCT observations, we calculate the timing of future transits and discuss the unique opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy.http://adsabs.harvard.edu/abs/2016DPS....4812208DPublished versio

    Comparing the Line Crossing Feature Approach with the Graph Approach for Invoice Automation

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    Di dalam dunia bisnis, invoice merupakan salah satu dokumen penting yang erat kaitannya dengan aktivitas penjualan dan pembelian di dalam suatu Perusahaan. Setiap invoice yang diperoleh oleh suatu Perusahaan akan menjadi sumber informasi atas berapa besarnya hutang atau piutang yang dimiliki oleh suatu Perusahaan. Ketika jumlah transaksi di dalam suatu Perusahaan masih tidak terlalu banyak, pencatatan invoice ke dalam database Perusahaan secara manual masih dimungkinkan. Mengingat bahwa jumlah transaksi di dalam suatu Perusahaan dapat menjadi besar, suatu metode untuk melakukan pencatatan invoice secara otomatis dapat membantu proses pencatatan data ke dalam database Perusahaan agar menjadi lebih efisien. Dua pendekatan pencatatan invoice secara otomatis yang akan dibandingkan di dalam karya ilmiah ini adalah Line Crossing Feature Approach dan Graph Approach. Berdasarkan perbandingan atas kelebihan dan kekurangan masing-masing pendekatan, Graph Approach secara pribadi dapat dinilai sebagai sebagai pendekatan yang lebih tepat untuk pencatatan invoice secara otomatis karena fleksibilitasnya dalam mengenali berbagai jenis dokumen. Kata kunci: invoice, information extraction, Line Crossing Feature Approach, Graph Approach, INFORMys metho

    The Line

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    The T-Wilson Line

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    We argue that soft-collinear effective theory, as is currently formulated, lacks an ingredient which is essential for obtaining a gauge invariant definitions of certain non-perturbative matrix elements relevant for semi-inclusive high-energy processes. Those processes and the companion cross-sections are to be analyzed and measured at the Large Hadron Collider. The missing feature is a gauge link constructed only from the transverse component of the gluon field denoted by the "TT-Wilson line"'. It is neither soft nor collinear. As such it is a new feature of the theory.Comment: 4 pages. To appear in the proceedings of "Quark Confinement and Hadron Nuclei", Madrid 201

    Redistricting: Drawing the Line

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    We develop methods to evaluate whether a political districting accurately represents the will of the people. To explore and showcase our ideas, we concentrate on the congressional districts for the U.S. House of representatives and use the state of North Carolina and its redistrictings since the 2010 census. Using a Monte Carlo algorithm, we randomly generate over 24,000 redistrictings that are non-partisan and adhere to criteria from proposed legislation. Applying historical voting data to these random redistrictings, we find that the number of democratic and republican representatives elected varies drastically depending on how districts are drawn. Some results are more common, and we gain a clear range of expected election outcomes. Using the statistics of our generated redistrictings, we critique the particular congressional districtings used in the 2012 and 2016 NC elections as well as a districting proposed by a bipartisan redistricting commission. We find that the 2012 and 2016 districtings are highly atypical and not representative of the will of the people. On the other hand, our results indicate that a plan produced by a bipartisan panel of retired judges is highly typical and representative. Since our analyses are based on an ensemble of reasonable redistrictings of North Carolina, they provide a baseline for a given election which incorporates the geometry of the state's population distribution.Comment: Corrected typos from previous version; added new plots showing stability; corrected error in EG plots and analysi

    Pulsations detected in the line profile variations of red giants: Modelling of line moments, line bisector and line shape

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    Contents: So far, red giant oscillations have been studied from radial velocity and/or light curve variations, which reveal frequencies of the oscillation modes. To characterise radial and non-radial oscillations, line profile variations are a valuable diagnostic. Here we present for the first time a line profile analysis of pulsating red giants, taking into account the small line profile variations and the predicted short damping and re-excitation times. We do so by modelling the time variations in the cross correlation profiles in terms of oscillation theory. Aims: The performance of existing diagnostics for mode identification is investigated for known oscillating giants which have very small line profile variations. We modify these diagnostics, perform simulations, and characterise the radial and non-radial modes detected in the cross correlation profiles. Methods: Moments and line bisectors are computed and analysed for four giants. The robustness of the discriminant of the moments against small oscillations with finite lifetimes is investigated. In addition, line profiles are simulated with short damping and re-excitation times and their line shapes are compared with the observations. Results: For three stars, we find evidence for the presence of non-radial pulsation modes, while for ξ\xi Hydrae perhaps only radial modes are present. Furthermore the line bisectors are not able to distinguish between different pulsation modes and are an insufficient diagnostic to discriminate small line profile variations due to oscillations from exoplanet motion.Comment: 12 pages, 10 figures, accepted by A&

    The Broad-Line and Narrow-Line Regions of the LINER NGC 4579

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    We report the discovery of an extremely broad H-alpha emission line in the LINER nucleus of NGC 4579. From ground-based observations, the galaxy was previously known to contain a Type 1 nucleus with a broad H-alpha line of FWHM = 2300 km/s and FWZI ~ 5000 km/s. New spectra obtained with the Hubble Space Telescope and a 0.2 arcsec-wide slit reveal an H-alpha component with FWZI ~ 18,000 km/s. The line is not obviously double-peaked, but it does possess shoulders on the red and blue sides which resemble the H-alpha profiles of double-peaked emitters such as NGC 4203 and NGC 4450. This similarity suggests that the very broad H-alpha profile in NGC 4579 may represent emission from an accretion disk. Three such objects have been found recently in two HST programs which have targeted a total of 30 galaxies, demonstrating that double-peaked or extremely broad-line emission in LINERs must be much more common than would be inferred from ground-based surveys. The ratio of the narrow [S II] 6716, 6731 lines shows a pronounced gradient indicating a steep rise in density toward the nucleus. The direct detection of a density gradient within the inner arcsecond of the narrow-line region confirms expectations from previous observations of linewidth-critical density correlations in several LINERs.Comment: 8 pages, includes 3 figures. To appear in The Astrophysical Journa

    The Narrow-Line Region of Narrow-Line Seyfert 1 Galaxies

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    We have studied the physical properties of a sample of narrow-line Seyfert 1 (NLS1) galaxies, and present a summary of our previous results, and new results. In particular, we have previously shown that (1) the locus of NLS1 galaxies on the M_BH-sigma_[OIII] plane does follow the relation of non-active galaxies after removing objects obviously dominated by outflows as evidenced by their [OIII] core blueshifts. We have (2) identified a number of so-called 'blue outliers' with large outflow velocities revealed by their emission-line kinematic shifts. We also (3) present new correlations and trends which link black hole mass, Eddington ratio and physical parameters of the emission-line regions.Comment: 9 pages, 6 figures, Proceedings of the Workshop "Narrow-Line Seyfert 1 Galaxies and Their Place in the Universe", Milano, April 4-6, 2011 (Proceedings of Science, http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=126
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