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Bayesian image reconstruction with space-variant noise suppression
Nunez, J.; Llacer, J.
In this paper we present a Bayesian image reconstruction algorithm with entropy prior (FMAPE) that uses a space-variant hyperparameter. The spatial variation of the hyperparameter allows different degrees of resolution in areas of different statistical characteristics, thus avoiding the large residuals resulting from algorithms that use a constant…
Surface photometry of early-type galaxies in the Hubble deep field
Fasano, G.; Filippi, M.
The detailed surface photometry of a sample of early-type galaxies in the Hubble Deep Field is presented as part of a long-term project aimed to settle strong observational constraints to the theories modelling the evolution of elliptical galaxies from the early stages. The sample has been extracted, in the V606 band, from the database …
Optical positions of compact extragalactic radio sources with respect to the HIPPARCOS Catalogue
Costa, E.; Loyola, P.
Optical positions relative to the Hipparcos Catalogue, and therefore within the International Celestial Reference System (ICRS), have been obtained for the optical counterparts of 25 compact extragalactic radio sources (CERS) south of delta ~ +10degr . Most of these sources are being monitored as Benchmark objects for the establishment of a unifie…
Crowded-field photometry from HST-imaging
Thomsen, B.; Sodemann, M.
We present a thorough investigation of stellar photometry based on HST imaging of crowded fields at 85arcsec and 10arcsec from the centre of the high-surface brightness elliptical galaxy M 32. The Principal Investigators of the present archive data have elsewhere presented an impressive colour-magnitude diagram of the field at 85arcsec . Based on …
Reduction of the Astrographic Catalogue, zone of S. Fernando
Vieira, K.; Abad, C.; Zambrano, A.
The San Fernando Zone of the Astrographic Catalogue is reduced to the HIPPARCOS system in order to test a reduction model previously presented by Abad (1993). A new method for the determination of field distortion and magnitude or color dependent systematic errors on photographic plates is discussed.
Mesures d'etoiles doubles effectuees a la lunette de 50 CM de l'Observatoire de Nice (2({) e. Measures of visual double stars made with the 50 CM refractor at the Nice Observatory (2^{nd
Thorel, J. -C.
66 measures of 38 visual double stars made at the Observatoire de la Cote d'Azur, at Nice, in september et december 1997, with the 50 cm equatorial refractor equipped with filar micrometer and electronic recording device. Observation programmes of stars suspected double and new binaries discovered by Hipparcos, and measures of double stars which h…
Stellar uvbybeta photometry in three EUV shadow directions
Knude, J.
We present the uvbybeta data used to locate the dust and derive distances for nearby diffuse interstellar clouds in the EUV shadows lb27-31, lb165-32 and lb329+46 discovered by the Extreme Ultraviolet Explorer. The photometrically derived parallaxes of our program stars are compared to the parallaxes listed in the Hipparcos Catalog. Within the pho…