2,587 research outputs found

    3D-Modellierung der MagnesitlagerstÀtte Hohentauern

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    Die LagerstĂ€tte Hohentauern liegt etwa 2 km nordwestlich des Triebensteins. Sie befindet sich im Karbon der Veitscher Teildecke innerhalb der nördlichen Grauwackenzone. Beim Ablagerungsmilieu handelt es sich um einen flachmarinen Bereich, der Mechanismus der Magnesitbildung ist noch nicht vollstĂ€ndig geklĂ€rt. Durch die NĂ€he zur Norischen Überschiebung und zur Oberostalpinen BasisĂŒberschiebung wurde der Magnesit tektonisch stark beansprucht. In Hohentauern baute die Veitscher Magnesit AG von 1907 bis 1991 den Magnesit ab, bis die Grube 1997 aufgelassen wurde. Aus den vorhandenen Bohrlochdaten und Grubenrissen sowie historischen Informationen wird ein dreidimensionales Modell der aus einzelnen Magnesitkörpern bestehenden LagerstĂ€tte erstellt. Das fertige Modell umfasst elf abbauwĂŒrdige Magnesitkörper, die in manchen Bereichen in Verbindung stehen. Trotz nicht mehr erhaltener Detailinformationen im Tagebaubereich konnte die Verbindung einzelner Körper zur TagesoberflĂ€che rekonstruiert werden. Die Arbeit enthĂ€lt eine detaillierte Beschreibung der Arbeitsschritte von der Digitalisierung der Daten bis hin zum 3D-Modell, das in Form eines VRML-Objekts im Internet veröffentlicht ist. Anhand des fertigen Modells werden eventuelle tektonische ZusammenhĂ€nge der einzelnen LagerstĂ€ttenkörper diskutiert. Der Winkel im unteren Bereich der LagerstĂ€tte stimmt mit der Bahn der BasisĂŒberschiebung des Oberostalpins ĂŒberein. Die ersichtliche Boudinage macht eine durch Tektonik hervorgerufene Zerteilung der Körper wahrscheinlich. Ob ursprĂŒnglich ein einziger Körper sedimentiert wurde oder ob mehrere Körper vor der tektonischen Beeinflussung vorgelegen haben, lĂ€sst sich durch das Modell nicht klĂ€ren. Sicherlich wurden alle Körper nachtrĂ€glich von der Boudinage geprĂ€gt. Das Geometriemodell bildet die Basis fĂŒr weitergehende Untersuchungen der LagerstĂ€tte, speziell der Variografie der QualitĂ€tsparameter.Elektronische Version der gedr. Ausg. von 200

    A High-Resolution Digital Terrain Model Mosaic of the Mars 2020 Perseverance Rover Landing Site at Jezero Crater

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    We demonstrate the capabilities of a published MADNet monocular height estimation network in producing a refined digital terrain model (DTM) mosaic at 50 cm/pixel resolution for the Mars 2020 Perseverance rover landing site in Jezero crater on Mars. Our approach utilizes the publicly available Mars 2020 Terrain Relative Navigation (TRN) High-Resolution Imaging Science Experiment (HiRISE) Digital Terrain Model (DTM) mosaic, which was originally created by the United States Geological Survey (USGS) Astrogeology Science Centre. Our resultant HiRISE MADNet DTM mosaic is strictly matched with the original HiRISE TRN DTM and orthoimage mosaics. These mosaics are themselves co-aligned with the USGS TRN Context Camera (CTX) based DTM and orthoimage mosaics, as well as the ESA/DLR/FUB (European Space Agency/German Aerospace Center/Free University Berlin) High Resolution Stereo Camera (HRSC) level 5 DTM and orthoimage mosaics. In this paper, we provide a brief description of the technical details, and present both visual and quantitative assessments of the refined MADNet HiRISE Jezero DTM mosaic product. This DTM product is now publicly available at http://dx.doi.org/10.17169/refubium-38359

    Dynamical evolution of AGN host galaxies -— gas in/out-flow rates in seven NUGA galaxies

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    To examine the role of the host galaxy structure in fueling nuclear activity, we estimated gas flow rates from several kpc down to the inner few 10 pc for seven nearby spiral galaxies, selected from the NUclei of GAlaxies sample. We calculated gravitational torques from near-infrared images and determined gas in/out-flow rates as a function of radius and location within the galactic disks, based on high angular resolution interferometric observations of molecular (CO using Plateau de Bure interferometer) and atomic (H I using the Very Large Array) gas. The results are compared with kinematic evidence for radial gas flows and the dynamical state of the galaxies (via resonances) derived from several different methods. We show that gravitational torques are very efficient at transporting gas from the outer disk all the way into the galaxies centers at ~100 pc; previously assumed dynamical barriers to gas transport, such as the corotation resonance of stellar bars, seem to be overcome by gravitational torque induced gas flows from other nonaxisymmetric structures. The resulting rates of gas mass inflow range from 0.01 to 50 M⊙ yr^(–1) and are larger for the galaxy center than for the outer disk. Our gas flow maps show the action of nested bars within larger bars for three galaxies. Noncircular streaming motions found in the kinematic maps are larger in the center than in the outer disk and appear to correlate only loosely with the in/out-flow rates as a function of radius. We demonstrate that spiral gas disks are very dynamic systems that undergo strong radial evolution on timescales of a few rotation periods (e.g., 5 × 10^8 yrs at a radius of 5 kpc), due to the effectiveness of gravitational torques in redistributing the cold galactic gas

    Large Area High-Resolution 3D Mapping of the Von Kármán Crater: Landing Site for the Chang’E-4 Lander and Yutu-2 Rover

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    We demonstrate the creation of a large area of high-resolution (260 × 209 km2 at 1 m/pixel) DTM mosaic from the Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images over the Chang’E-4 landing site at Von KĂĄrmĂĄn crater using an in-house deep learning-based 3D modelling system developed at University College London, called MADNet, trained with lunar orthorectified images and digital terrain models (DTMs). The resultant 1 m DTM mosaic is co-aligned with the Chang’E-2 (CE-2) and the Lunar Orbiter Laser Altimeter (LOLA)—SELenological and Engineering Explorer (SELENE) blended DTM product (SLDEM), providing high spatial and vertical congruence. In this paper, technical details are briefly discussed, along with visual and quantitative assessments of the resultant DTM mosaic product. The LROC NAC MADNet DTM mosaic was compared with three independent DTM datasets, and the mean differences and standard deviations are as follows: PDS photogrammetric DTM at 5 m grid-spacing had a mean difference of −0.019 ± 1.09 m, CE-2 DTM at 20 m had a mean difference of −0.048 ± 1.791 m, and SLDEM at 69 m had a mean difference of 0.577 ± 94.940 m. The resultant LROC NAC MADNet DTM mosaic, alongside a blended LROC NAC and CE-2 MADNet DTM mosaic and a separate LROC NAC, orthorectified image mosaic, are made publicly available via the ESA planetary science archive’s guest storage facility

    An Explanation for the Observed Weak Size Evolution of Disk Galaxies

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    Surveys of distant galaxies with the Hubble Space Telescope and from the ground have shown that there is only mild evolution in the relationship between radial size and stellar mass for galactic disks from z~1 to the present day. Using a sample of nearby disk-dominated galaxies from the Sloan Digital Sky Survey (SDSS), and high redshift data from the GEMS (Galaxy Evolution from Morphology and SEDs) survey, we investigate whether this result is consistent with theoretical expectations within the hierarchical paradigm of structure formation. The relationship between virial radius and mass for dark matter halos in the LCDM model evolves by about a factor of two over this interval. However, N-body simulations have shown that halos of a given mass have less centrally concentrated mass profiles at high redshift. When we compute the expected disk size-stellar mass distribution, accounting for this evolution in the internal structure of dark matter halos and the adiabatic contraction of the dark matter by the self-gravity of the collapsing baryons, we find that the predicted evolution in the mean size at fixed stellar mass since z~1 is about 15-20 percent, in good agreement with the observational constraints from GEMS. At redshift z~2, the model predicts that disks at fixed stellar mass were on average only 60% as large as they are today. Similarly, we predict that the rotation velocity at a given stellar mass (essentially the zero-point of the Tully-Fisher relation) is only about 10 percent larger at z~1 (20 percent at z~2) than at the present day.Comment: 13 pages, 6 figures, accepted for publication in ApJ. Revised in response to referee's comments to improve clariry. Results are unchange

    GEMS: Galaxy Evolution from Morphologies and SEDs

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    GEMS, Galaxy Evolution from Morphologies and SEDs, is a large-area (800 arcmin2) two-color (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on HST. Centered on the Chandra Deep Field South, it covers an area of ~28'x28', or about 120 Hubble Deep Field areas, to a depth of m_AB(F606W)=28.3 (5sigma and m_AB(F850LP)=27.1 (5sigma) for compact sources. In its central ~1/4, GEMS incorporates ACS imaging from the GOODS project. Focusing on the redshift range 0.2<=z<=1.1, GEMS provides morphologies and structural parameters for nearly 10,000 galaxies where redshift estimates, luminosities and SEDs exist from COMBO-17. At the same time, GEMS contains detectable host galaxy images for several hundred faint AGN. This paper provides an overview of the science goals, the experiment design, the data reduction and the science analysis plan for GEMS.Comment: 24 pages, TeX with 6 eps Figures; to appear in ApJ Supplement. Low resolution figures only. Full resolution at http://zwicky.as.arizona.edu/~rix/Misc/GEMS.ps.g

    GEMS: Galaxy fitting catalogues and testing parametric galaxy fitting codes

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    In the context of measuring structure and morphology of intermediate redshift galaxies with recent HST/ACS surveys, we tune, test, and compare two widely used fitting codes (GALFIT and GIM2D) for fitting single-component Sersic models to the light profiles of both simulated and real galaxy data. We find that fitting accuracy depends sensitively on galaxy profile shape. Exponential disks are well fit with Sersic models and have small measurement errors, whereas fits to de Vaucouleurs profiles show larger uncertainties owing to the large amount of light at large radii. We find that both codes provide reliable fits and little systematic error, when the effective surface brightness is above that of the sky. Moreover, both codes return errors that significantly underestimate the true fitting uncertainties, which are best estimated with simulations. We find that GIM2D suffers significant systematic errors for spheroids with close companions owing to the difficulty of effectively masking out neighboring galaxy light; there appears to be no work around to this important systematic in GIM2D's current implementation. While this crowding error affects only a small fraction of galaxies in GEMS, it must be accounted for in the analysis of deeper cosmological images or of more crowded fields with GIM2D. In contrast, GALFIT results are robust to the presence of neighbors because it can simultaneously fit the profiles of multiple companions thereby deblending their effect on the fit to the galaxy of interest. We find GALFIT's robustness to nearby companions and factor of >~20 faster runtime speed are important advantages over GIM2D for analyzing large HST/ACS datasets. Finally we include our final catalog of fit results for all 41,495 objects detected in GEMS.Comment: Accepted for publication in ApJS October 2007, v172n2; 25 pages, 16 Figures, 9 Tables; for hi-resolution version, see http://www.mpia.de/homes/bhaeussl/galaxy_fitting.pdf. For results, catalogues and files for code-testing, see http://www.mpia.de/GEMS/fitting_paper.htm

    Differential associations of emotional and physical domains of the MacNew Heart with changes in 6-min walking test

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    Aims Cardiac rehabilitation (CR), a key component of secondary prevention in cardiac patients, contributes fundamentally to improved cardiovascular health outcomes. Health-related quality of life (HRQOL) represents a widely employed outcome measure in CR, yet, its predictive properties on exercise capacity change during CR are poorly understood. Aim of this study was to examine the association between baseline HRQOL and its subdomains on improvement of exercise capacity during CR. Methods Study participants were 13,717 inpatients of six Swiss CR clinics from 2012 to 2018. We measured HRQOL at admission to CR with the MacNew Heart (MNH) questionnaire and exercise capacity at admission and discharge using the six minutes walking test (6MWT). Following factorial analyses, we performed univariate and multivariate analyses to test the predictive properties of baseline global HRQOL and its domains for improvement in exercise capacity, adjusting for demographic and clinical characteristics. Results Mean improvement in 6MWT was 114 m (SD = 90), achieved after 17.4 days (SD = 5.5). Lower emotional HRQOL (b = 7.85, p =  < .001, 95% CI [− 5.67, 10.03]) and higher physical HRQOL (b =  − 5.23, p < .001, 95% CI [− 6.56, − 3.90]) were associated with less improvement in the 6MWT. Global MNH and social HRQOL showed no association with exercise capacity improvement. Conclusion Patients entering CR with low emotional and high physical HRQOL are at risk for a lower gain in exercise capacity during CR. Global MNH alone does not provide a reliable assessment of HRQOL; thus a focus on specific domains of HRQOL is needed
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