The density field of the 10k zCOSMOS galaxies

K. Kovač, S. J. Lilly, O. Cucciati, C. Porciani, A. Iovino, G. Zamorani, P. Oesch, M. Bolzonella, C. Knobel, A. Finoguenov, Y. Peng, C. M. Carollo, L. Pozzetti, K. Caputi, J. D. Silverman, L. A.M. Tasca, M. Scodeggio, D. Vergani, N. Z. Scoville, P. CapakT. Contini, J. P. Kneib, O. Le Fèvre, V. Mainieri, A. Renzini, S. Bardelli, A. Bongiorno, G. Coppa, S. De La Torre, L. De Ravel, P. Franzetti, B. Garilli, L. Guzzo, P. Kampczyk, F. Lamareille, J. F. Le Borgne, V. Le Brun, C. Maier, M. Mignoli, R. Pello, E. Perez Montero, E. Ricciardelli, M. Tanaka, L. Tresse, E. Zucca, U. Abbas, D. Bottini, A. Cappi, P. Cassata, A. Cimatti, M. Fumana, A. M. Koekemoer, D. MacCagni, C. Marinoni, H. J. McCracken, P. Memeo, B. Meneux, R. Scaramella

Research output: Contribution to journalArticle

90 Citations (Scopus)

Abstract

We use the current sample of ∼10,000 zCOSMOS spectra of sources selected with I AB < 22.5 to define the density field out to z ∼ 1, with much greater resolution in the radial dimension than has been possible with either photometric redshifts or weak lensing. We present the new algorithm that we have developed (ZADE) to incorporate objects not yet observed spectroscopically by modifying their photometric redshift probability distributions using the spectroscopic redshifts of nearby galaxies. We present a number of tests on mock catalogs used to justify this approach. The ZADE algorithm allows us to probe a broader range of galaxy environments and reduce the Poisson noise in the density field. The reconstructed overdensity field of the 10k zCOSMOS galaxies consists of cluster-like patterns surrounded by void-like regions, extending up to z ∼ 1. Some of these structures are very large, spanning the ∼ 50 h -1 Mpc transverse direction of the COSMOS field and extending up to Δz ∼ 0.05 in redshift. We present the three-dimensional overdensity maps and compare the reconstructed overdensity field to the independently identified virialized groups of galaxies and clusters detected in the visible and in X-rays. The distribution of the overdense structures is in general well traced by these virialized structures. A comparison of the large-scale structures in the zCOSMOS data and in the mock catalogs reveals an excellent agreement between the fractions of the volume enclosed in structures of all sizes above a given overdensity between the data and the mocks in 0.2 < z < 1, although in the data these overdense regions are in generally larger contiguous structures.

Original languageEnglish
Pages (from-to)505-533
Number of pages29
JournalAstrophysical Journal
Volume708
Issue number1
DOIs
Publication statusPublished - 2010

Keywords

  • Galaxies: high-redshift
  • Large-scale structure of universe
  • Surveys

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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  • Cite this

    Kovač, K., Lilly, S. J., Cucciati, O., Porciani, C., Iovino, A., Zamorani, G., Oesch, P., Bolzonella, M., Knobel, C., Finoguenov, A., Peng, Y., Carollo, C. M., Pozzetti, L., Caputi, K., Silverman, J. D., Tasca, L. A. M., Scodeggio, M., Vergani, D., Scoville, N. Z., ... Scaramella, R. (2010). The density field of the 10k zCOSMOS galaxies. Astrophysical Journal, 708(1), 505-533. https://doi.org/10.1088/0004-637X/708/1/505