We present a photometric and spectroscopic study of galaxies at 0.5<z<1 as a function of environment based on data from the zCOSMOS survey. There is a fair amount of evidence that galaxy properties depend on mass of groups and clusters, in the sense that quiescent galaxies prefer more massive systems. We base our analysis on a mass-selected environment using X-ray groups of galaxies and define the group membership using a large number of spectroscopic redshifts from zCOSMOS. We show that the fraction of red galaxies is higher in groups than in the field at all redshifts probed in our study. Interestingly, the fraction of [OII] emitters on the red sequence increases at higher redshifts in groups, while the fraction does not strongly evolve in the field. This is due to increased dusty star formation activities and/or increased activities of active galactic nuclei (AGNs) in high redshift groups. We study these possibilities using the 30-band photometry and X-ray data. We find that the stellar population of the red [OII] emitters in groups is old and there is no clear hint of dusty star formation activities in those galaxies. The observed increase of red [OII] emitters in groups is likely due to increased AGN activities. However, our overall statistics is poor and any firm conclusions need to be drawn from a larger statistical sample of z~1 groups.

X-Ray Groups of Galaxies at 0.5 < z < 1 in zCOSMOS: Increased AGN Activities in High Redshift Groups

CUCCIATI, OLGA;CIMATTI, ANDREA;MORESCO, MICHELE ENNIO MARIA;
2012

Abstract

We present a photometric and spectroscopic study of galaxies at 0.5
2012
Tanaka Masayuki; Finoguenov Alexis; Lilly Simon J.; Bolzonella Micol; Carollo C. Marcella; Contini Thierry; Iovino Angela; Kneib Jean-Paul; Lamareille Fabrice; Le Fevre Olivier; Mainieri Vincenzo; Presotto Valentina; Renzini Alvio; Scodeggio Marco; Silverman John D.; Zamorani Gianni; Bardelli Sandro; Bongiorno Angela; Caputi Karina; Cucciati Olga; de la Torre Sylvain; de Ravel Loic; Franzetti Paolo; Garilli Bianca; Kampczyk Pawel; Knobel Christian; Kovac Katarina; Le Borgne Jean-Francois; Le Brun Vincent; López-Sanjuan Carlos; Maier Christian; Mignoli Marco; Pello Roser; Peng Yingjie; Perez-Montero Enrique; Tasca Lidia; Tresse Laurence; Vergani Daniela; Zucca Elena; Barnes Luke; Bordoloi Rongmon; Cappi Alberto; Cimatti Andrea; Coppa Graziano; Koekemoer Anton M.; McCracken Henry J.; Moresco Michele; Nair Preethi; Oesch Pascal; Pozzetti Lucia; Welikala Niraj
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/392160
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