A GROUP-GALAXY CROSS-CORRELATION FUNCTION ANALYSIS IN zCOSMOS

Journal Article · Fri Aug 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/755/1/48· OSTI ID:22039149

Knobel, C; Lilly, S J; Carollo, C M; Caputi, K ^[1]; Contini, T ^[2]; Kneib, J -P; Le Fevre, O ^[3]; Mainieri, V ^[4]; Renzini, A ^[5]; Scodeggio, M; Franzetti, P; Garilli, B ^[6]; Zamorani, G; Bardelli, S; Bolzonella, M ^[7]; Bongiorno, A ^[8]; Cucciati, O; Iovino, A ^[9]; De la Torre, S; De Ravel, L ^[10] ; others, and

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1. Institute for Astronomy, ETH Zurich, Zurich 8093 (Switzerland)
2. Institut de Recherche en Astrophysique et Planetologie, CNRS, 14, avenue Edouard Belin, F-31400 Toulouse (France)
3. Laboratoire d'Astrophysique de Marseille, CNRS/Aix-Marseille Universite, 38 rue Frederic Joliot-Curie, 13388, Marseille Cedex 13 (France)
4. European Southern Observatory, Garching (Germany)
5. INAF-Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122, Padova (Italy)
6. INAF-IASF Milano, Milano (Italy)
7. INAF Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127, Bologna (Italy)
8. Max-Planck-Institut fuer Extraterrestrische Physik, Garching (Germany)
9. INAF Osservatorio Astronomico di Brera, Milan (Italy)
10. Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH93HJ (United Kingdom)

We present a group-galaxy cross-correlation analysis using a group catalog produced from the 16,500 spectra from the optical zCOSMOS galaxy survey. Our aim is to perform a consistency test in the redshift range 0.2 {<=} z {<=} 0.8 between the clustering strength of the groups and mass estimates that are based on the richness of the groups. We measure the linear bias of the groups by means of a group-galaxy cross-correlation analysis and convert it into mass using the bias-mass relation for a given cosmology, checking the systematic errors using realistic group and galaxy mock catalogs. The measured bias for the zCOSMOS groups increases with group richness as expected by the theory of cosmic structure formation and yields masses that are reasonably consistent with the masses estimated from the richness directly, considering the scatter that is obtained from the 24 mock catalogs. Some exceptions are the richest groups at high redshift (estimated to be more massive than 10{sup 13.5} M{sub Sun }), for which the measured bias is significantly larger than for any of the 24 mock catalogs (corresponding to a 3{sigma} effect), which is attributed to the extremely large structure that is present in the COSMOS field at z {approx} 0.7. Our results are in general agreement with previous studies that reported unusually strong clustering in the COSMOS field.

• OSTI ID: 22039149
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 755; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
CATALOGS
CORRELATION FUNCTIONS
CORRELATIONS
COSMOLOGY
EMISSION SPECTRA
GALAXIES
GALAXY CLUSTERS
MASS
RED SHIFT
STATISTICS
UNIVERSE