593 research outputs found

    The Euclid Archive Processing and Data Distribution Systems: A Distributed Infrastructure for Euclid and Associated Data

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    The Euclid Archive System is an ambitious information system, which sits at the heart of the Euclid Science Ground Segment. It is a joint development between the Euclid Consortium and the ESAC Science Data Centre. It encompases both Euclid data and the large volume of associated ground based data (e.g. KiDS, DES and LSST). The Euclid Science Ground Segment consists of the Euclid Science Operations Centre and ten national Science Data Centres. The large data volumes demand that data transfer is minimized and that the processing is taken to the data. This is supported by the Euclid Archive Data Processing System and the Euclid Archive Distributed Data System. The Data Processing System consists of a central metadata repository, which contains the information necessary to process any data item and full data lineage of any data product created. The Distributed Data System provides a cloud solution with a node at each of the national Science Data Centres, which controls data storage and transfer. It supports a large number of storage types, including POSIX, iRODS, gridftp and Xrootd. No limitations are placed on the storage implemented at an individual SDC. Further more, the user of the system needs no knowledge of where data is located. Jobs will be started at the most appropriate locations, or data transferred as necessary

    The Role of the Euclid Archive System in the Processing of Euclid and External Data

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    Euclid is an ESA M2 mission which will create a 15,000 square degrees space-based survey: the Euclid Archive System (EAS) is a core element of the Science Ground Segment (SGS) of Euclid. The EAS follows a data-centric approach to data processing, whereby the Data Processing System (DPS) is responsible for the centralized metadata storage and the Distributed Storage System (DSS) supports the distributed storage of data files. The EAS-DPS implements the Euclid Common Data model and along with the EAS-DSS provides numerous services for Euclid Consortium users and SGS subsystems. In addition, the EAS-DPS assists in the preparation of Euclid data releases which are copied to the third EAS subsystem, the ESA developed Science Archive System (SAS) where they become available to the wider astronomical community. The EAS-DPS implements the object-oriented Euclid Common Data Model using a relational DBMS for the storage. The EAS-DPS supports the tracing of the lineage of any data item in the system, provides services for the data quality assessment and the data processing orchestration. The EAS-DSS is a distributed storage system which is based on a set of storage nodes located in each of the ten Science Data Centers of the Euclid SGS. The storage nodes supports a wide range of solutions from local disk, using a unix filesystem, to iRODS nodes or Grid storage elements. In this paper the architectural design of EAS-DPS and EAS-DSS are reviewed: the interaction between them and tests of the already implemented components are described

    The Euclid Archive Processing and Data Distribution Systems: A Distributed Infrastructure for Euclid and Associated Data

    Get PDF
    The Euclid Archive System is an ambitious information system, which sits at the heart of the Euclid Science Ground Segment. It is a joint development between the Euclid Consortium and the ESAC Science Data Centre. It encompases both Euclid data and the large volume of associated ground based data (e.g. KiDS, DES and LSST). The Euclid Science Ground Segment consists of the Euclid Science Operations Centre and ten national Science Data Centres. The large data volumes demand that data transfer is minimized and that the processing is taken to the data. This is supported by the Euclid Archive Data Processing System and the Euclid Archive Distributed Data System. The Data Processing System consists of a central metadata repository, which contains the information necessary to process any data item and full data lineage of any data product created. The Distributed Data System provides a cloud solution with a node at each of the national Science Data Centres, which controls data storage and transfer. It supports a large number of storage types, including POSIX, iRODS, gridftp and Xrootd. No limitations are placed on the storage implemented at an individual SDC. Further more, the user of the system needs no knowledge of where data is located. Jobs will be started at the most appropriate locations, or data transferred as necessary

    Broadband Quasi-Periodic Radio and X-ray Pulsations in a Solar Flare

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    We describe microwave and hard X-ray observations of strong quasiperiodic pulsations from the GOES X1.3 solar flare on 15 June 2003. The radio observations were made jointly by the Owens Valley Solar Array (OVSA), the Nobeyama Polarimeter (NoRP), and the Nobeyama Radioheliograph (NoRH). Hard X-ray observations were made by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Using Fourier analysis, we study the frequency- and energy-dependent oscillation periods, differential phase, and modulation amplitudes of the radio and X-ray pulsations. Focusing on the more complete radio observations, we also examine the modulation of the degree of circular polarization and of the radio spectral index. The observed properties of the oscillations are compared with those derived from two simple models for the radio emission. In particular, we explicitly fit the observed modulation amplitude data to the two competing models. The first model considers the effects of MHD oscillations on the radio emission. The second model considers the quasi-periodic injection of fast electrons. We demonstrate that quasiperiodic acceleration and injection of fast electrons is the more likely cause of the quasiperiodic oscillations observed in the radio and hard X-ray emission, which has important implications for particle acceleration and transport in the flaring sources.Comment: ApJ, accepte
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