Signature of Supersonic Turbulence in Galaxy Clusters Revealed by AGN-driven Hα Filaments
| Autor: | Haojie Hu, Yu Qiu, Marie-Lou Gendron-Marsolais, Tamara Bogdanović, Julie Hlavacek-Larrondo, Luis C. Ho, Kohei Inayoshi, Brian R. McNamara |
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| Přispěvatelé: | Ministerio de Ciencia e Innovación (España), European Commission |
| Rok vydání: | 2022 |
| Předmět: |
Intracluster medium
Space and Planetary Science Astrophysics::High Energy Astrophysical Phenomena Galaxy winds Astronomy and Astrophysics Galaxy clusters Astrophysics::Cosmology and Extragalactic Astrophysics GeneralLiterature_REFERENCE(e.g. dictionaries encyclopedias glossaries) Astrophysics - Astrophysics of Galaxies Astrophysics::Galaxy Astrophysics Filamentary nebulae |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The hot intracluster medium (ICM) is thought to be quiescent with low observed velocity dispersions. Surface brightness fluctuations of the ICM also suggest that its turbulence is subsonic with a Kolmogorov scaling relation, indicating that the viscosity is suppressed and the kinetic energy cascades to small scales unscathed. However, recent observations of the cold gas filaments in galaxy clusters find that the scaling relations are steeper than that of the hot plasma, signaling kinetic energy losses and the presence of supersonic flows. In this work we use high-resolution simulations to explore the turbulent velocity structure of the cold filaments at the cores of galaxy clusters. Our results indicate that supersonic turbulent structures can be "frozen" in the cold gas that cools and fragments out of a fast, ∼107 K outflow driven by the central active galactic nucleus (AGN), when the radiative cooling time is shorter than the dynamical sound-crossing time. After the cold gas formation, however, the slope of the velocity structure function (VSF) flattens significantly over short, ∼10 Myr timescales. The lack of flattened VSF in observations of Hα filaments indicates that the Hα-emitting phase is short-lived for the cold gas in galaxy clusters. On the other hand, the ubiquity of supersonic turbulence revealed by observed filaments strongly suggests that supersonic outflows are an integral part of AGN–ICM interaction, and that AGN activity plays a crucial role at driving turbulence in galaxy clusters. © 2022. The Author(s). Published by the American Astronomical Society. This work is supported by the National Natural Science Foundation of China (12003003, 12073003, 11721303, 11991052, 11950410493), the China Postdoctoral Science Foundation (2020T130019), the National Key R&D Program of China (2016YFA0400702), and the High-Performance Computing Platform of Peking University. M.G. acknowledges financial support from grant RTI2018-096228-B-C31 (MCIU/AEI/FEDER, UE), from the coordination of the participation in SKA-SPAIN financed by the Ministry of Science and Innovation (MICIN), and from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the "Center of Excellence Severo Ochoa" awarded to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). |
| Databáze: | OpenAIRE |
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