CHEX-MATE: X-ray surface brightness discontinuities across a representative cluster sample
Abstract
We analyze the presence of X-ray surface brightness (SB) discontinuities, such as shocks and cold fronts, in the intracluster medium (ICM) of the 116 galaxy clusters from the CHEX-MATE sample. These features arise from accretion-related processes, including the merging of subclumps onto the main cluster halo and the sloshing of cold gas in a higher-entropy environment. We identify these structures in the XMM CHEX-MATE maps by examining both the SB residuals, obtained by subtracting a cluster model from the observations, and the gradient variations across X-ray images. We validate our method with an extensive analysis and comparison of the discontinuities described already in the literature. Our analysis reveals 66 discontinuities, 32 of which are newly detected, in 48 objects (∼41%). We find that discontinuities in relaxed systems tend to be closer to the core, weaker, and less aligned with the global X-ray morphology compared to those in disturbed systems. Using wavelet-based temperature maps, we provide a preliminary classification of these discontinuities, proposing the occurrence of 8 putative shocks and 34 cold fronts. Furthermore, about 48% of the systems with extended radio emission show evidence of ICM discontinuities; conversely, ∼88% of the objects with detected discontinuities have an associated diffuse radio emission. This work also explores the limitations of using XMM data, characterized by relatively low spatial resolution, for detecting and analyzing such features, highlighting the challenges and potential biases introduced by instrumental constraints.
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BibTeX
@misc{campitiello2026chexmate,
title = {{CHEX-MATE: X-ray surface brightness discontinuities across a representative cluster sample}},
author = {Maria Giulia Campitiello and Stefano Ettori and Lorenzo Lovisari and Fabio Gastaldello and Hervé Bourdin and Pasquale Mazzotta and Mariachiara Rossetti and Marco Balboni and Andrea Botteon and Rossella Cassano and Federico de Luca and Dominique Eckert and William Forman and Massimo Gaspari and Simona Ghizzardi and Myriam Gitti and Scott T Kay and Ben J Maughan and Etienne Pointecouteau and Gabriel W Pratt and Elena Rasia and Jack Sayers and Mauro Sereno},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.13610},
eprint = {2609.13610},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05782751v1},
}
RIS
TY - UNPB
TI - CHEX-MATE: X-ray surface brightness discontinuities across a representative cluster sample
AU - Maria Giulia Campitiello
AU - Stefano Ettori
AU - Lorenzo Lovisari
AU - Fabio Gastaldello
AU - Hervé Bourdin
AU - Pasquale Mazzotta
AU - Mariachiara Rossetti
AU - Marco Balboni
AU - Andrea Botteon
AU - Rossella Cassano
AU - Federico de Luca
AU - Dominique Eckert
AU - William Forman
AU - Massimo Gaspari
AU - Simona Ghizzardi
AU - Myriam Gitti
AU - Scott T Kay
AU - Ben J Maughan
AU - Etienne Pointecouteau
AU - Gabriel W Pratt
AU - Elena Rasia
AU - Jack Sayers
AU - Mauro Sereno
PY - 2026
DA - 2026/09/11
PB - HAL
DO - 10.48550/arxiv.2609.13610
UR - https://hal.science/hal-05782751v1
AB - We analyze the presence of X-ray surface brightness (SB) discontinuities, such as shocks and cold fronts, in the intracluster medium (ICM) of the 116 galaxy clusters from the CHEX-MATE sample. These features arise from accretion-related processes, including the merging of subclumps onto the main cluster halo and the sloshing of cold gas in a higher-entropy environment. We identify these structures in the XMM CHEX-MATE maps by examining both the SB residuals, obtained by subtracting a cluster model from the observations, and the gradient variations across X-ray images. We validate our method with an extensive analysis and comparison of the discontinuities described already in the literature. Our analysis reveals 66 discontinuities, 32 of which are newly detected, in 48 objects (∼41%). We find that discontinuities in relaxed systems tend to be closer to the core, weaker, and less aligned with the global X-ray morphology compared to those in disturbed systems. Using wavelet-based temperature maps, we provide a preliminary classification of these discontinuities, proposing the occurrence of 8 putative shocks and 34 cold fronts. Furthermore, about 48% of the systems with extended radio emission show evidence of ICM discontinuities; conversely, ∼88% of the objects with detected discontinuities have an associated diffuse radio emission. This work also explores the limitations of using XMM data, characterized by relatively low spatial resolution, for detecting and analyzing such features, highlighting the challenges and potential biases introduced by instrumental constraints.
ER -