22,671 research outputs found

    'The Brick' is not a brick : A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016

    Get PDF
    Ā© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.In this paper we provide a comprehensive description of the internal dynamics of G0.253+0.016 (a.k.a. 'the Brick'); one of the most massive and dense molecular clouds in the Galaxy to lack signatures of widespread star formation. As a potential host to a future generation of high-mass stars, understanding largely quiescent molecular clouds like G0.253+0.016 is of critical importance. In this paper, we reanalyse Atacama Large Millimeter Array cycle 0 HNCO J=4(0,4)āˆ’3(0,3)J=4(0,4)-3(0,3) data at 3 mm, using two new pieces of software which we make available to the community. First, scousepy, a Python implementation of the spectral line fitting algorithm scouse. Secondly, acorns (Agglomerative Clustering for ORganising Nested Structures), a hierarchical n-dimensional clustering algorithm designed for use with discrete spectroscopic data. Together, these tools provide an unbiased measurement of the line of sight velocity dispersion in this cloud, Ļƒvlos,1D=4.4Ā±2.1\sigma_{v_{los}, {\rm 1D}}=4.4\pm2.1 kmsāˆ’1^{-1}, which is somewhat larger than predicted by velocity dispersion-size relations for the Central Molecular Zone (CMZ). The dispersion of centroid velocities in the plane of the sky are comparable, yielding Ļƒvlos,1D/Ļƒvpos,1Dāˆ¼1.2Ā±0.3\sigma_{v_{los}, {\rm 1D}}/\sigma_{v_{pos}, {\rm 1D}}\sim1.2\pm0.3. This isotropy may indicate that the line-of-sight extent of the cloud is approximately equivalent to that in the plane of the sky. Combining our kinematic decomposition with radiative transfer modelling we conclude that G0.253+0.016 is not a single, coherent, and centrally-condensed molecular cloud; 'the Brick' is not a \emph{brick}. Instead, G0.253+0.016 is a dynamically complex and hierarchically-structured molecular cloud whose morphology is consistent with the influence of the orbital dynamics and shear in the CMZ.Peer reviewedFinal Accepted Versio

    Pharr-Reynosa International Bridge: Continued Archeological and Historical Research at El Capote Ranch Community, Hidalgo County, Texas

    Get PDF
    Phase II cultural resources investigations for the Pharr-Reynosa International Bridge currently under construction in Hidalgo County, Texas, were conducted by Prewitt and Associates, Inc. in September 1993 and June 1994. The work included additional survey and documentation of seven historic sites, testing and evaluation of three sites, archival and oral history research on the former Hispanic community of EI Capote, and collection of additional geoarcheological data. The seven historic sites (4IHG162-41HG168) represent former nineteenth- and twentieth-century housesites within EI Capote. Due to a lack of integrity, it is recommended that all seven sites be considered ineligible for listing on the National Register of Historic Places. Three other probable historic sites (Garza Ranch No.2, a segment of the Old Military Road, and the de la Viila Ranch) are located outside the area of potential effects. These were not recorded, but their locations are noted. Also outside the area of potential effects, a historic housesite (4IHG 169) contains the only known standing dwelling associated with nineteenth-century EI Capote. Mechanical and hand excavations of the historic components at 41HG153 and 41HG158 revealed severe disturbances and lack of intact features. It is recommended that these site~ be considered ineligible for listing on the National Register. Surface and subsurface search for additional evidence of prehistoric occupations at 41HG153 yielded one artifact. It is recommended that the prehistoric component at 41HG153 also be considered ineligible for listing on the National Register. Mapping and recording of features at a historic brick factory confirmed the site\u27s high archeological integrity. Site 41HG156 is the only Ranching Period brick kiln known in the Lower Rio Grande Valley of Texas. It is recommended that it be considered eligible for listing onĀ·the National Register

    Kashmir Pakistand Earthquake of October 8 2005. A Field Report by EEFIT

    Get PDF

    Seismology and seismic hazard

    Get PDF

    Landslides and Geotechnical Aspects

    Get PDF

    The geology of strata exposed in Roade railway cutting, Northamptonshire : engineering phase Priority 3 sections and overall assessment

    Get PDF
    This report describes the geology of the bedrock strata at the Roade railway cutting (a Site of Special Scientific Interest), near Northampton, exposed by engineering works between 2006 and 2010 and made available to the BGS for detailed examination. Strata exposed previously during engineering works between 2005 and 2006 (engineering phases Priority 1 & 2) are described in a companion report (Barron and Woods, 2010). The exposed strata, totalling about 8 m in thickness, belong entirely to the Blisworth Limestone Formation of the Great Oolite Group, which is of Mid Jurassic age. Neither the base nor top of the formation are exposed. The current report includes text descriptions and graphic sections of the localities examined, a plan of the cutting showing locations and the distribution of the strata with correlations, close-up photographs of the bedrock exposed, and photographic panoramas of the cutting sides. It also includes an assessment of the exposed strata in terms of their sedimentary facies and lateral variability

    Ghana airborne geophysics project in the Volta and Keta Basin : BGS final report

    Get PDF
    This report describes the work undertaken by BGS between November 2006 and March 2009 in collaboration with Fugro Airborne Surveys Pty Ltd on an airborne geophysical survey and ground reconnaissance mapping of the Volta River and Keta Basins, Ghana. The project was supported by the EU as part of the Mining Sector Support Programme, Project Number 8ACP GH 027/13. The initial contract duration was three years, but this was extended by five months to account for acquisition of gravity data by another project. Some parts of Ghana have been airborne surveyed as part of the Mining Sector Development and Environmental Project, co-funded by the World Bank and the Nordic Development Fund, but no work was carried out on the Volta River and Keta basins, which together form a major portion of the Ghanaian territory. The approximate areas covered by the surveys are estimated at 98,000 kmĀ² for the satellite imagery and the airborne geophysics, except for the Time Domain Electromagnetic (TDEM) survey which was limited to 60,000 kmĀ². The main beneficiary of this project is the Geological Survey Department, GSD. The work enhanced its geological infrastructure and its personnel received hands-on training on modern geological mapping technology. Indirect beneficiaries were the mining and exploration companies that can follow up the reconnaissance work with detailed exploration work. The project was conducted in five phases, and this document reports on the BGS input to Phase 1, 4 and 5, with no inputs required in Phases 2 and 3: ā€¢ Phase1: geological outline through Radar and optical satellite imageries. ā€¢ Phase 2: airborne geophysical survey over the two basins for magnetics and Gamma Ray spectrometry (Fugro survey). ā€¢ Phase 3: airborne electromagnetic and magnetic geophysical survey of specific areas, following the completion and interpretation of phase 2, using fixed wing time domain technology (Fugro survey). ā€¢ Phase 4: interpretation of the combined geology and geophysics. ā€¢ Phase 5: production of factual and interpretation maps. The full list of BGS products is outlined in Table 1 below, while Jordan et al. (2006) describe the products delivered on schedule in Phase 1

    iTools a Facilitatorā€™s Tool Kit of Deliberate Intuition Tools

    Get PDF
    The purpose of this masterā€™s project was to contribute to Janice Francisco and Cyndi Burnettā€™s (2008) research on deliberate intuition within the Creative Problem Solving Thinking Skills Model (CPSTSM) framework developed by Puccio, Murdock & Mance (2007). 16 intuition tools, ā€œitoolsā€ (Francisco & Burnett, 2008) aimed at tapping into deliberate intuition as an integral component of the creative process, were collected, described, developed, and grouped into 4 categories; Quick & Dirty, Artsy Fartsy, Yellow Brick Road, and Abracadabra. The importance of setting intention was highlighted as an integral component of any itool, as well as the need for more research into ways in which consciousness and ā€˜other-than-consciousnessā€™ is defined and addressed within the intuitive process. This collection serves as an initial itool kit, with testing and validation to follow
    • ā€¦
    corecore