187 research outputs found

    The Footprint Database and Web Services of the Herschel Space Observatory

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    Data from the Herschel Space Observatory is freely available to the public but no uniformly processed catalogue of the observations has been published so far. To date, the Herschel Science Archive does not contain the exact sky coverage (footprint) of individual observations and supports search for measurements based on bounding circles only. Drawing on previous experience in implementing footprint databases, we built the Herschel Footprint Database and Web Services for the Herschel Space Observatory to provide efficient search capabilities for typical astronomical queries. The database was designed with the following main goals in mind: (a) provide a unified data model for meta-data of all instruments and observational modes, (b) quickly find observations covering a selected object and its neighbourhood, (c) quickly find every observation in a larger area of the sky, (d) allow for finding solar system objects crossing observation fields. As a first step, we developed a unified data model of observations of all three Herschel instruments for all pointing and instrument modes. Then, using telescope pointing information and observational meta-data, we compiled a database of footprints. As opposed to methods using pixellation of the sphere, we represent sky coverage in an exact geometric form allowing for precise area calculations. For easier handling of Herschel observation footprints with rather complex shapes, two algorithms were implemented to reduce the outline. Furthermore, a new visualisation tool to plot footprints with various spherical projections was developed. Indexing of the footprints using Hierarchical Triangular Mesh makes it possible to quickly find observations based on sky coverage, time and meta-data. The database is accessible via a web site (http://herschel.vo.elte.hu) and also as a set of REST web service functions.Comment: Accepted for publication in Experimental Astronom

    The NASA/IPAC Infrared Science Archive (IRSA) as a resource in supporting observatory operations

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    IRSA's scaleable and extensible architecture is inherited by new missions and data providers, and thus offers substantial cost savings to missions. It has built archives for the W.M. Keck Observatory & the Spitzer Space Telescope Legacy teams, among others. It provided archiving and databases support for 2MASS, when active, and will provide corresponding support for the forthcoming WISE mission. IRSA acts as a resource to projects and missions by advising on product design and providing tools for validating data products

    A deep X-ray view of Stripe-82: improving the data legacy in the search for new Blazars

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    In the era of big data, multi-messenger astrophysics and abundant computa- tional resources, strategic uses of the available resources are key to address current data analysis demands. In this work, we developed a novel techno- logical approach to a fully automated data processing pipeline for Swift-XRT observations, where all images ever observed by the satellite are downloaded and combined to provide the deepest view of the Swift x-ray sky; Sources are automatically identified and their fluxes are measured in four differ- ent bands. The pipeline runs autonomously, implementing a truly portable model, finally uploading the results to a central VO-compliant server to build a science-ready, continuously-updated photometric catalog. We applied the Swift- DeepSky pipeline to the whole Stripe-82 region of the sky to build the deep- est X-ray sources catalog to the region; down to ≈ 2 × 10−16 erg s−1cm−2 (0.2-10 keV). Such catalog was used to the identification of Blazar candidates detected only after the DeepSky pipeline

    The NASA/IPAC Infrared Science Archive (IRSA) as a resource in supporting observatory operations

    Get PDF
    IRSA's scaleable and extensible architecture is inherited by new missions and data providers, and thus offers substantial cost savings to missions. It has built archives for the W.M. Keck Observatory & the Spitzer Space Telescope Legacy teams, among others. It provided archiving and databases support for 2MASS, when active, and will provide corresponding support for the forthcoming WISE mission. IRSA acts as a resource to projects and missions by advising on product design and providing tools for validating data products

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie
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