Charting Cluster Construction with VUDS and ORELSE


The Charting Cluster Construction with VUDS and ORELSE (C3VO) survey, an ongoing campaign designed to provide a nearly complete mapping of the five most significant overdensities detected in VIMOS Ultra–Deep Survey (VUDS, see Fig 1, and the list of protoclusters in Fields), The C3VO survey utilizes spectra from observations with both DEIMOS and MOSFIRE on the Keck I/II telescopes (see Fig 2) and VUDS, and employs the Voronoi Monte-Carlo algorithm for local environment measurement, originally developed within the framework of the ORELSE survey,. The keck component of the C3VO survey is designed to target star-forming galaxies of all types to i_AB < 25.3 (or ∼ L*FUV at z ∼ 4.5 and < L*FUV at z ∼ 2.5) and Lyman-α emitting galaxies to fainter magnitudes.

The main goals are:
  • Mapping the growth of structure from z~0.5 to z~5
  • Probing the evolution of galaxies in LSSs across cosmic time
  • Develop detection methods to find forming clusters (protoclusters)
  • Detection biases for proto-clusters using different galaxy types
  • Relationship between, color, star-formation, stellar mass, AGN activity, and density
  • Characterizing the virialization state of protoclusters


Fig. 1. Footprint of VIMOS Ultra–Deep Survey (VUDS) and other imaging surveys in COSMOS, ECDFS and CFHTLS-D1 field (from left to right).

The C3VO-Keck Campaign

Fig. 2. The improvement of protocluster identification with high spectroscopic fraction. Left: Examples of the overdensity maps using only spectra of Keck DEIMOS/MOSFIRE conducted as part of C3VO. Right top: the photometric redshift versus redshift from Keck spectra. Right bottom: Histograms of spectroscopically-confirmed redshift from Keck DEIMOS and MOSFIRE from C3VO survey.

C3VO Massive Protostructures

Hyperion: Proto-structure at z ~ 2.5 in the COSMOS field (Cucciati et al. 2018)
Protocluster PClJ1000+0200 at z ~ 2.9 in the COSMOS field (Cucciati et al. 2014)
Proto-structure PCl J0227-0421 at z ~ 3.3 in the CFHTLS-D1 field (Lemaux et al. 2014, Shen et al. 2021)
Elentári: Proto-structure at z ~ 3.3 in the COSMOS field (Forrest et al. 2023)
Protocluster at z ~ 3.5 in the ECDFS field (shah et al. in prep)
Protocluster PCl J1001+0220 at z ~ 4.6 in the COSMOS field (Lemaux et al. 2018, Staab et al. in prep)