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arXiv · 2503.21724

Ram-pressure stripping caught in action in a young cluster at $z = 2.51$

Ke Xu·Tao Wang·Emanuele Daddi·David Elbaz·Hanwen Sun·Longyue Chen·Qiaoyang Hao·Raphael Gobat·Anita Zanella·Daizhong Liu·Mengyuan Xiao·Renyue Cen·Tadayuki Kodama·Kotaro Kohno·Tiancheng Yang·Can Xu·Zhi-Yu Zhang·Luwenjia Zhou·Francesco Valentino
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Abstract

Galaxy clusters in the local Universe are dominated by massive quiescent galaxies with old ages, formed at high redshifts. Whether their quenching is driven by internal processes or environmental effects is a matter of debate that has been challenging to resolve due to the lack of observations during their peak formation epoch. Here we report clear evidence from the Atacama Large Millimeter/submillimeter Array of extended and elongated gas tails in five galaxies in a forming cluster at z = 2.51. The single-tailed gas distributions, which extend notably beyond the stellar emission probed by JWST in galaxies that are relatively isolated and lack signatures of mergers or interactions (features that are very uncommon in the field), provide evidence of ram-pressure stripping. These very distant confirmed cases of ram-pressure stripping highlight the critical role of environmental effects in gas removal at high redshifts, an often-overlooked quenching pathway.

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Ke Xu, Tao Wang, Emanuele Daddi, David Elbaz, Hanwen Sun, Longyue Chen, Qiaoyang Hao, Raphael Gobat, Anita Zanella, Daizhong Liu, Mengyuan Xiao, Renyue Cen, Tadayuki Kodama, Kotaro Kohno, Tiancheng Yang, Can Xu, Zhi-Yu Zhang, Luwenjia Zhou, Francesco Valentino. 2025-03-27. Ram-pressure stripping caught in action in a young cluster at $z = 2.51$. https://doi.org/10.1038/s41550-026-02892-9

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