A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F25%3A00144625" target="_blank" >RIV/00216224:14310/25:00144625 - isvavai.cz</a>
Result on the web
<a href="https://iopscience.iop.org/article/10.3847/2041-8213/ae2609" target="_blank" >https://iopscience.iop.org/article/10.3847/2041-8213/ae2609</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3847/2041-8213/ae2609" target="_blank" >10.3847/2041-8213/ae2609</a>
Alternative languages
Result language
angličtina
Original language name
A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM
Original language description
Hierarchical mergers of galaxy clusters play a key role in converting gravitational energy into thermal and kinetic energy in the local Universe. Understanding this process requires the reconstruction of cluster merger geometry, with careful consideration of projection effects. With its unprecedented spectral resolution, XRISM enables the disentanglement of merging cluster components along the line of sight via X-rays for the first time. In this Letter, we focus on the massive cluster A1914, a puzzling case wherein the galaxy and dark matter (DM) distribution appear to be in tension with the X-ray morphology. We present XRISM observations of A1914 focusing on the velocity structure of the intracluster medium. The Resolve full-array spectrum requires two merging components along the line of sight, with bulk velocities offset by ∼1000 km s-1 and velocity dispersions of ∼200 km s-1. The subarray maps of flux ratios, bulk velocity, and velocity dispersion show the two components are offset and overlapping in the plane of the sky, consistent with a major (mass ratio ∼3), near line-of-sight merger with a pericenter distance of ∼200 kpc. We conclude that the two subclusters create an overlapping spiral pattern, referred to as a "yin-yang" merger. This scenario is further supported by tailored hydrodynamical simulations of the A1914 merger, demonstrating that this type of merger can broadly reproduce the observed X-ray morphology, gas temperature map, gas velocity maps, DM distribution, and galaxy velocities. This work demonstrates the power of high-resolution X-ray spectroscopy, provided by XRISM, to resolve complex cluster merger geometries.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
<a href="/en/project/GX21-13491X" target="_blank" >GX21-13491X: Exploring the Hot Universe and Understanding Cosmic Feedback</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
ASTROPHYSICAL JOURNAL LETTERS
ISSN
2041-8205
e-ISSN
2041-8213
Volume of the periodical
995
Issue of the periodical within the volume
2
Country of publishing house
GB - UNITED KINGDOM
Number of pages
11
Pages from-to
1-11
UT code for WoS article
001637294000001
EID of the result in the Scopus database
2-s2.0-105033959409