Examinando por Autor "Brescia, M."

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    The VOICE Survey : VST Optical Imaging of the CDFS and ES1 Fields
    (Proceedings of Science (PoS), 2016-01) Vaccari, M.; Covone, G.; Radovich, M.; Grado, A.; Limatola, L.; Botticella, M.T.; Cappellaro, E.; Paolillo, M.; Pignata, G.; De Cicco, D.; Falocco, S.; Marchetti, L.; Brescia, M.; S., Cavuoti; Longo, G.; Capaccioli, M.; Napolitano, N.; Schipani, P.
    We present the VST Optical Imaging of the CDFS and ES1 Fields (VOICE) Survey, a VST INAF Guaranteed Time program designed to provide optical coverage of two 4 deg2 cosmic windows in the Southern hemisphere. VOICE provides the first, multi-band deep optical imaging of these sky regions, thus complementing and enhancing the rich legacy of longer-wavelength surveys with VISTA, Spitzer, Herschel and ATCA available in these areas and paving the way for upcoming observations with facilities such as the LSST, MeerKAT and the SKA. VOICE exploits VST's OmegaCAM optical imaging capabilities and completes the reduction of WFI data available within the ES1 fields as part of the ESO-Spitzer Imaging Extragalactic Survey (ESIS) program providing ugri and uBVR coverage of 4 and 4 deg2 areas within the CDFS and ES1 field respectively. We present the survey's science rationale and observing strategy, the data reduction and multi-wavelength data fusion pipeline. Survey data products and their future updates will be released at http://www.mattiavaccari.net/voice/ and on CDS/VizieR.
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    Weak-lensing study in VOICE survey - I. Shear measurement
    (Oxford University Press, 2018-09) Fu, L.; Liu, D.; Radovich, M.; Liu, X.; Pan, C.; Fan, Z.; Covone, G.; Vaccari, M.; Amaro, V.; Brescia, M.; Capaccioli, M.; De Cicco, D.; Grado, A.; Limatola, L.; Miller, L.; Napolitano, N.R.; Paolillo, M.; Pignata, G.
    The VST Optical Imaging of the CDFS and ES1 Fields (VOICE) Survey is a Guaranteed Time programme carried out with the European Southern Observatory (ESO) VLT Survey Telescope (VST) telescope to provide deep optical imaging over two 4 deg2 patches of the sky centred on the Chandra Deep Field South (CDFS) and ES1 as part of the ESO-Spitzer Imaging Extragalactic Survey. We present the cosmic shear measurement over the 4 deg2 covering the CDFS region in the r band using LensFit. Each of the four tiles of 1 deg2 has more than 100 exposures, of which more than 50 exposures passed a series of image quality selection criteria for weak-lensing study. The 5σ limiting magnitude in r band is 26.1 for point sources, which is ≳1 mag deeper than other weak-lensing survey in the literature [e.g. the Kilo Degree Survey (KiDS) at VST]. The photometric redshifts are estimated using the VOICE u, g, r, i together with near-infrared VIDEO data Y, J, H, Ks. The mean redshift of the shear catalogue is 0.87, considering the shear weight. The effective galaxy number density is 16.35 gal arcmin-2, which is nearly twice the one of KiDS. The performance of LensFit on such a deep data set was calibrated using VOICE-like mock image simulations. Furthermore, we have analysed the reliability of the shear catalogue by calculating the star-galaxy crosscorrelations, the tomographic shear correlations of two redshift bins and the contaminations of the blended galaxies. As a further sanity check, we have constrained cosmological parameters by exploring the parameter space with Population Monte Carlo sampling. For a flat Λ cold dark matter model, we have obtained Σ8 = σ8(Ωm/0.3)0.5 = 0.68+0.11 -0.15. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.