A Chandra view of SPT-CL J0217–5014: A massive galaxy cluster at a cosmic intersection at z = 0.53

¹ Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University Kotlářská 2 Brno 611 37, Czech Republic
² School of Physics and Astronomy, Shanghai Jiao Tong University Dongchuan Road 800 Shanghai 200240, China
³ National Astronomical Observatories, Chinese Academy of Sciences 20A Datun Road Beijing 100101, PR China
⁴ Department of Astronomy, Tsinghua University Beijing 100084, PR China
⁵ Department of Physics and Astronomy, University of Kentucky 505 Rose Street Lexington KY 40506, USA
⁶ NASA Goddard Space Flight Center, Code 662 Greenbelt MD 20771, USA
⁷ SRON Netherlands Institute for Space Research Niels Bohrweg 4 2333 CA Leiden, The Netherlands

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Received: 19 August 2025
Accepted: 3 December 2025

Abstract

Context. Galaxy clusters trace the densest regions of the cosmic web and are crucial laboratories for studying the thermodynamic and chemical evolution of the intracluster medium (ICM). The massive galaxy cluster SPT-CL J0217−5014 (z ∼ 0.53; M₅₀₀ ∼ 3 × 10¹⁴ M_⊙) is one of the Swift X-Ray Telescope serendipitous galaxy clusters with the highest reported Fe abundance (∼1.3 ± 0.4 Z_⊙ within ∼ 1_.^′7) and a potentially disturbed morphology.

Aims. SPT-CL J0217−5014 presents an intriguing opportunity to investigate ICM chemical enrichment and cool-core survival. With this study, we aim to evaluate its chemical and thermodynamic properties with a dedicated Chandra observation.

Methods. Using new Chandra observations, we derived surface brightness profiles and dynamical state parameters. We also performed spectral fitting using different backgrounds to constrain the Fe abundance. We performed joint analysis of the X-ray surface brightness, temperature, and integrated Sunyaev-Zel’dovich Compton parameter to constrain the density profile. The DESI optical galaxy cluster catalogue was examined to explore its large-scale environment.

Results. The X-ray morphology reveals a disturbed ICM with a surface brightness edge at ∼ 0_.^′26 (∼100 kpc) to the west and a tail-like feature extending towards the east. The best-fit metal abundance within $1\stackrel{\prime }{.}5$ (∼0.7 R₅₀₀) is 0.61^+0.26_−0.23 Z_⊙. The derived central electron number density, entropy, and cooling time classify this system as a non-cool-core cluster, suggesting that merger activity has likely disrupted the possible pre-existing cool core. At larger radii (∼1′−2′), we detected excess X-ray emission to the south spatially aligned with a filamentary distribution of red galaxies, indicating ongoing accretion along an intracluster filament. Based on the DESI DR9 cross-matched optical clusters and photometric redshifts, we identified three nearby lower-mass clusters that likely trace the large-scale structures, suggesting that SPT-CL J0217−5014 is the primary node of a dynamically active environment where past mergers and anisotropic accretion along cosmic filaments have shaped the present-day ICM.