A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM

J 2025

A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM

HEINRICH, Annie; Congyao ZHANG; Irina ZHURAVLEVA; Eugene CHURAZOV; Hannah MCCALL et al.

Základní údaje

Originální název

A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM

Autoři

HEINRICH, Annie; Congyao ZHANG; Irina ZHURAVLEVA; Eugene CHURAZOV; Hannah MCCALL; Reinout J. VAN WEEREN a William R. FORMAN

Vydání

ASTROPHYSICAL JOURNAL LETTERS, Bristol, IOP Publishing Ltd, 2025, 2041-8205

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 11.700 v roce 2024

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/25:00144625

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

Galaxy clusters; Intracluster medium; High energy astrophysics

Štítky

14312040, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 27. 4. 2026 08:47, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

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.

Návaznosti

GX21-13491X, projekt VaV

Název: Zkoumání žhavého vesmíru a porozumění kosmické zpětné vazbě (Akronym: EHU)

Investor: Grantová agentura ČR, Exploring the Hot Universe and Understanding Comic Feedback

Citovat

HEINRICH, Annie; Congyao ZHANG; Irina ZHURAVLEVA; Eugene CHURAZOV; Hannah MCCALL; Reinout J. VAN WEEREN a William R. FORMAN. A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM. ASTROPHYSICAL JOURNAL LETTERS. Bristol: IOP Publishing Ltd, 2025, roč. 995, č. 2, s. 1-11. ISSN 2041-8205. Dostupné z: https://doi.org/10.3847/2041-8213/ae2609.

@article{2548388,
   author = {Heinrich, Annie and Zhang, Congyao and Zhuravleva, Irina and Churazov, Eugene and McCall, Hannah and van Weeren, Reinout J. and Forman, William R.},
   article_location = {Bristol},
   article_number = {2},
   doi = {https://doi.org/10.3847/2041-8213/ae2609},
   keywords = {Galaxy clusters; Intracluster medium; High energy astrophysics},
   language = {eng},
   issn = {2041-8205},
   journal = {ASTROPHYSICAL JOURNAL LETTERS},
   title = {A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM},
   url = {https://iopscience.iop.org/article/10.3847/2041-8213/ae2609},
   volume = {995},
   year = {2025}
}

TY  - JOUR
ID  - 2548388
AU  - Heinrich, Annie - Zhang, Congyao - Zhuravleva, Irina - Churazov, Eugene - McCall, Hannah - van Weeren, Reinout J. - Forman, William R.
PY  - 2025
TI  - A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM
JF  - ASTROPHYSICAL JOURNAL LETTERS
VL  - 995
IS  - 2
SP  - 1-11
EP  - 1-11
PB  - IOP Publishing Ltd
SN  - 20418205
KW  - Galaxy clusters
KW  - Intracluster medium
KW  - High energy astrophysics
UR  - https://iopscience.iop.org/article/10.3847/2041-8213/ae2609
N2  - 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.
ER  -

HEINRICH, Annie; Congyao ZHANG; Irina ZHURAVLEVA; Eugene CHURAZOV; Hannah MCCALL; Reinout J. VAN WEEREN a William R. FORMAN. A Yin-yang Galaxy Cluster Merger in A1914 Revealed by XRISM. \textit{ASTROPHYSICAL JOURNAL LETTERS}. Bristol: IOP Publishing Ltd, 2025, roč.~995, č.~2, s.~1-11. ISSN~2041-8205. Dostupné z: https://doi.org/10.3847/2041-8213/ae2609.

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