CLASH-VLT: Abell S1063

Cluster assembly history and spectroscopic catalogue

¹ INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
e-mail: amata.mercurio@inaf.it
² Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
³ INAF – OAS, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy
⁴ INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy
⁵ IFPU – Institute for Fundamental Physics of the Universe, Via Beirut 2, 34014 Trieste, Italy
⁶ Centro de Astrobiología, Instituto Nacional de Técnica Aeroespacial, Ctra de Torrejón a Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain
⁷ Dipartimento di Fisica, Univ. degli Studi di Trieste, Via Tiepolo 11, 34143 Trieste, Italy
⁸ Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
⁹ INAF – IASF Milano, Via A. Corti 12, 20133 Milano, Italy
¹⁰ OmegaLambdaTec GmbH, Lichtenbergstrasse 8, 85748 Garching bei Munchen, Germany
¹¹ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
¹² Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla, 4059 Valparaíso, Chile
¹³ Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85748 Garching, Germany
¹⁴ Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians Universität München, Scheinerstr. 1, 81679 München, Germany
¹⁵ INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 50125 Firenze, Italy
¹⁶ INFN–Sezione di Trieste, Trieste, Italy
¹⁷ Departamento de Astronomía, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile
¹⁸ INAF – Osservatorio Astronomico di Brera, Via Brera 28, 20121 Milano, Italy
¹⁹ Institute for Particle Physics and Astrophysics, ETH Zürich, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
²⁰ Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
²¹ Carnegie Observatories, 813 Santa Barbara Street, Pasadena, California 91101, USA
²² University of Vienna, Department of Astrophysics, Tuerkenschanzstrasse 17, 1180 Vienna, Austria
²³ Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA
²⁴ Dipartimento di Fisica e Astronomia, Universitá degli Studi di Padova, Padova, Italy

Received: 7 September 2021
Accepted: 30 October 2021

Abstract

Context. The processes responsible for galaxy evolution in different environments as a function of galaxy mass remain heavily debated. Rich galaxy clusters are ideal laboratories in which to distinguish the role of environmental versus mass quenching because they consist of a full range of galaxies and environments.

Aims. Using the CLASH-VLT survey, we assembled an unprecedentedly large sample of 1234 spectroscopically confirmed members in Abell S1063. We found a dynamically complex structure at ⟨z_cl⟩ = 0.3457 with a velocity dispersion σ_v = 1380₋₃₂⁺²⁶ km s⁻¹. We investigated cluster environmental and dynamical effects by analysing the projected phase-space diagram and the orbits as a function of galaxy spectral properties.

Methods. We classified cluster galaxies according to the presence and strength of the [OII] emission line, the strength of the Hδ absorption line, and colours. We investigated the relation between the spectral classes of galaxies and their position in the projected phase-space diagram. We separately analysed red and blue galaxy orbits. By correlating the observed positions and velocities with the projected phase-space constructed from simulations, we constrained the accretion redshift of galaxies with different spectral types.

Results. Passive galaxies are mainly located in the virialised region, while emission-line galaxies lie beyond r₂₀₀ and are accreted into the cluster at a later time. Emission-line and post-starburst galaxies show an asymmetric distribution in projected phase-space within r₂₀₀; emission-line galaxies are prominent at Δv/σ ≲ −1.5 and post-starburst galaxies at Δv/σ ≳ 1.5, suggesting that backsplash galaxies lie at high positive velocities. We find that low-mass passive galaxies are accreted into the cluster before high-mass galaxies. This suggests that we observe as passives only the low-mass galaxies that are accreted early into the cluster as blue galaxies. They had the time to quench their star formation. We also find that red galaxies move on more radial orbits than blue galaxies. This can be explained if infalling galaxies can remain blue by moving on tangential orbits.