The XXL Survey

XLIV. Sunyaev-Zel’dovich mapping of a low-mass cluster at z ∼ 1: a multi-wavelength approach^⋆,⋆⋆

¹ Laboratoire d’Annecy de Physique des Particules, Université Savoie Mont Blanc, CNRS/IN2P3, 74941 Annecy, France
e-mail: marina.ricci@lapp.in2p3.fr
² Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Blvd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
³ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, planta 2, 44001 Teruel, Spain
⁴ LLR, CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
⁵ Department of Astronomy, University of Geneva, Ch. d’Ecogia 16, 1290 Versoix, Switzerland
⁶ Astronomy Instrumentation Group, University of Cardiff, Cardiff, UK
⁷ AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité, 91191 Gif-sur-Yvette, France
⁸ Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
⁹ European Space Astronomy Centre (ESA/ESAC), Operations Department, Villanueva de la Canãda, Madrid, Spain
¹⁰ Institut d’Astrophysique Spatiale (IAS), CNRS and Université Paris Sud, Orsay, France
¹¹ Institut Néel, CNRS and Université Grenoble Alpes, Grenoble, France
¹² Institut de RadioAstronomie Millimétrique (IRAM), Grenoble, France
¹³ HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
¹⁴ Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble Alpes, CNRS/IN2P3, 53 avenue des Martyrs, Grenoble, France
¹⁵ Istituto Nazionale di Astrofisica (INAF) – Osservatorio di Astrofisica e Scienza dello Spazio (OAS), via Gobetti 93/3, 40127 Bologna, Italy
¹⁶ INAF – IASF Milan, via A. Corti 12, 20133 Milano, Italy
¹⁷ Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy
¹⁸ Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
¹⁹ Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, 28850 Madrid, Spain
²⁰ Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
²¹ Institute for Astronomy & Astrophysics, Space Applications & Remote Sensing, National Observatory of Athens, 15236 Palaia Penteli, Greece
²² Institut de RadioAstronomie Millimétrique (IRAM), Granada, Spain
²³ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
²⁴ LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, 75014 Paris, France
²⁵ School of Earth and Space Exploration and Department of Physics, Arizona State University, Tempe, AZ 85287, USA
²⁶ Argelander Institut für Astronomie, Universität Bonn, Auf dem Huegel 71, 53121 Bonn, Germany
²⁷ European Southern Observatory, Alonso de Cordova 3107, Vitacura, 19001 Casilla, Santiago 19, Chile
²⁸ LPENS, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France
²⁹ Institut d’Astrophysique de Paris, Sorbonne Universités, UPMC Univ. Paris 06, CNRS UMR 7095, 75014 Paris, France
³⁰ INFN, Sezione di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
³¹ Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan

Received: 3 December 2019
Accepted: 4 March 2020

Abstract

High-mass clusters at low redshifts have been intensively studied at various wavelengths. However, while more distant objects at lower masses constitute the bulk population of future surveys, their physical state remain poorly explored to date. In this paper, we present resolved observations of the Sunyaev-Zel’dovich (SZ) effect, obtained with the NIKA2 camera, towards the cluster of galaxies XLSSC 102, a relatively low-mass system (M₅₀₀ ∼ 2 × 10¹⁴ M_⊙) at z = 0.97 detected from the XXL survey. We combine NIKA2 SZ data, XMM-Newton X-ray data, and Megacam optical data to explore, respectively, the spatial distribution of the gas electron pressure, the gas density, and the galaxies themselves. We find significant offsets between the X-ray peak, the SZ peak, the brightest cluster galaxy, and the peak of galaxy density. Additionally, the galaxy distribution and the gas present elongated morphologies. This is interpreted as the sign of a recent major merging event, which induced a local boost of the gas pressure towards the north of XLSSC 102 and stripped the gas out of the galaxy group. The NIKA2 data are also combined with XXL data to construct the thermodynamic profiles of XLSSC 102, obtaining relatively tight constraints up to about ∼r₅₀₀, and revealing properties that are typical of disturbed systems. We also explore the impact of the cluster centre definition and the implication of local pressure substructure on the recovered profiles. Finally, we derive the global properties of XLSSC 102 and compare them to those of high-mass-and-low-redshift systems, finding no strong evidence for non-standard evolution. We also use scaling relations to obtain alternative mass estimates from our profiles. The variation between these different mass estimates reflects the difficulty to accurately measure the mass of low-mass clusters at z ∼ 1, especially with low signal-to-noise ratio data and for a disturbed system. However, it also highlights the strength of resolved SZ observations alone and in combination with survey-like X-ray data. This is promising for the study of high redshift clusters from the combination of eROSITA and high resolution SZ instruments and will complement the new generation of optical surveys from facilities such as LSST and Euclid.