ESA Science & Technology - Publication Archive
Publication archive
Publication archive
Aims. LYRA, the Large Yield Radiometer, is a vacuum ultraviolet (VUV) solar radiometer, planned to be launched in November 2009 on the European Space Agency PROBA2, the Project for On-Board Autonomy spacecraft.
Methods. The instrument was radiometrically calibrated in the radiometry laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the Berlin Electron Storage ring for SYnchroton radiation (BESSY II). The calibration was done using monochromatized synchrotron radiation at PTBs VUV and soft X-ray radiometry beamlines using reference detectors calibrated with the help of an electrical substitution radiometer as the primary detector standard.
Results. A total relative uncertainty of the radiometric calibration of the LYRA instrument between 1% and 11% was achieved. LYRA will provide irradiance data of the Sun in four UV passbands and with high temporal resolution down to 10 ms. The present state of the LYRA pre-flight calibration is presented as well as the expected instrument performance.
We review the formalism and applications of the halo-based description of non-linear gravitational clustering. In this approach, all mass is associated with virialized dark matter halos; models of the number and spatial distribution of the halos, and the distribution of dark matter within each halo, are used to provide estimates of how the statistical properties of large scale density and velocity fields evolve as a result of non-linear gravitational clustering. We first describe the model, and demonstrate its accuracy by comparing its predictions with exact results from numerical simulations of non-linear gravitational clustering. We then present several astrophysical applications of the halo model: these include models of the spatial distribution of galaxies, the non-linear velocity, momentum and pressure fields, descriptions of weak gravitational lensing, and estimates of secondary contributions to temperature fluctuations in the cosmic microwave background.
This report, the so-called Yellow Book, contains the results of ESA's assessment study (Phase 0/A) of the candidate L-class Cosmic Vision mission LISA.
This report, the so-called Yellow Book, contains the results of ESA's assessment study (Phase 0/A) of the candidate L-class Cosmic Vision mission IXO.
This report, the so-called Yellow Book, contains the results of ESA's assessment study (Phase 0/A) of the candidate L-class Cosmic Vision mission EJSM-Laplace.
This technical review report for the LISA candidate mission presents the outcome of an ESA internal review of this L-class candidate mission in the Cosmic Vision 2015-2025 plan. The review was concluded at the end of the mission assessment phase and carried out in frame of the down-selection for L-class missions to proceed to the definition phase. The review focused on the technical and programmatic elements of the mission.
This technical review report for the EJSM-Laplace candidate mission presents the outcome of an ESA internal review of this L-class candidate mission in the Cosmic Vision 2015-2025 plan. The review was concluded at the end of the mission assessment phase and carried out in frame of the down-selection for L-class missions to proceed to the definition phase. The review focused on the technical and programmatic elements of the mission.
This technical review report for the IXO candidate mission presents the outcome of an ESA internal review of this L-class candidate mission in the Cosmic Vision 2015-2025 plan. The review was concluded at the end of the mission assessment phase and carried out in frame of the down-selection for L-class missions to proceed to the definition phase. The review focused on the technical and programmatic elements of the mission.