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A Protocluster at z = 2.45

Diener, C. and Lilly, S. J. and Ledoux, C. and Zamorani, G. and Bolzonella, M. and Murphy, D. N. A. and Capak, P. and Ilbert, O. and McCracken, H. (2015) A Protocluster at z = 2.45. Astrophysical Journal, 802 (1). Art. No. 31. ISSN 0004-637X. doi:10.1088/0004-637X/802/1/31.

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We present the spectroscopic confirmation of a z = 2.45 protocluster. Its member galaxies lie within a radius of 1.4 Mpc (physical) on the sky and within Δv ± 700 km^(-1) along the line of sight. We estimate an overdensity of 10, suggesting that the structure has made the turnaround but is not assembled yet. A comparison to the Millennium simulation suggests that analogous structures evolve into 10^(14)–10^(15) M_⊙h^(−1) type dark matter halos by z = 0, qualifying the notion of "protocluster." The search for the complete census of mock progenitor galaxies at z ~ 2.5 of these massive z = 0 mock clusters reveals that they are widely spread over areas with a diameter of 3–20 Mpc. This suggests that the optical selection of such protoclusters can result in a rich diversity regarding their z = 0 descendants. We also searched for signs of environmental differentiation in this protocluster. While we see a weak trend for more massive and more quiescent galaxies within the protocluster, this is not statistically significant.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Lilly, S. J.0000-0002-6423-3597
Capak, P.0000-0003-3578-6843
Ilbert, O.0000-0002-7303-4397
McCracken, H.0000-0002-9489-7765
Additional Information:© 2015 American Astronomical Society. Received 2014 November 3; accepted 2014 December 29; published 2015 March 18. This research has been supported by the Swiss National Science Foundation (SNF) and the European Southern Observatory (ESO). It is based on observations undertaken at the ESO Very Large Telescope (VLT) under Program 290.A-5160(A). It also uses data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO program ID 179.A-2005 and data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium. The Millennium simulation databases used in this paper and the Web application providing online access to them were constructed as part of the activities of the German Astrophysical Virtual Observatory.
Group:COSMOS, Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Swiss National Science Foundation (SNSF)UNSPECIFIED
European Southern ObservatoryUNSPECIFIED
Subject Keywords:galaxies: clusters: general; galaxies: high-redshift
Issue or Number:1
Record Number:CaltechAUTHORS:20150424-115610914
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Official Citation:A Protocluster at z = 2.45 C. Diener et al. 2015 ApJ 802 31
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:56955
Deposited On:24 Apr 2015 21:19
Last Modified:10 Nov 2021 21:05

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