Galaxies and AGN - Clusters of galaxies


Groups and clusters of galaxies are the most massive, virialized objects in the Universe, and contain over half of all present-day galaxies. They are important laboratories to study the evolution of the galaxy population, as well as useful cosmological probes. Three specific projects concerning clusters and groups of galaxies are carried out at OAPd: WINGS has created a high quality multi-wavelength dataset for galaxies in a large and well-selected sample of nearby clusters; the PM2GC is a new catalogue of groups, binaries and single galaxies in the local Universe with high quality photometric and spectroscopic data, and BUDHIES is a deep HI and multiwavelength survey of galaxies in two superclusters at z~0.2.

 WINGS has obtained integrated and aperture photometry (B,V bands) of ~400000 galaxies in 77 clusters, that have yielded surface photometry and morphologies for ~45000 galaxies; U, J and K photometry for a subset of clusters; and optical spectroscopy and new redshifts for about 6000 galaxies. Results obtained so far from WINGS include studies of the evolution of the fundamental plane and ellipticity distribution of early-type galaxies, of Brightest Cluster Galaxies properties, morphologies, galaxy stellar mass functions, frequency and properties of superdense galaxies, color-magnitude red sequence and star formation histories. The PM2GC, based on the good quality imaging and highly complete spectroscopic coverage of the Millennium Galaxy Catalogue, has yielded magnitudes, stellar masses, morphologies, sizes and surface photometry parameters, star formation rates and histories for a complete sample of galaxies at z=0.04-0.1. PM2GC results so far include the investigation of the distribution of galaxy morphologies and mass functions in groups, binary systems and single galaxies and as a function of galaxy local density, the incidence of superdense galaxies and the mass-size relation at low-z, and the stellar population properties of galaxies of different types in different environments. BUDHIES is the first survey to study neutral atomic hydrogen gas in galaxies at z~0.2, a redshift where evolutionary processes begin to show. Based on a ultra-deep Westerbork Synthesis Radio Telescope large programme, it includes deep optical, GALEX, Spitzer and Herschel photometry, as well as optical spectroscopy. The two survey fields contain two clusters of galaxies (A2192 and A963), as well as an area 12X12 Mpc on the sky for a depht of 328 Mpc, sampling cluster surroundings, groups, filaments and voids. BUDHIES results so far include a detailed characterization of the first field, A2192, the identification of four substructures within the main system, and a detailed study of galaxy HI content, star formation, morphology and stellar mass in the different substrutures.

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Cluster of Galaxies - PAST STUDIES

Edu INAF - Risorse e iniziative per la scuola e la società dell'INAF

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