Deprojecting galaxy-cluster cold fronts: evidence for bulk, magnetized spiral flows

Author:

Naor Yossi1,Keshet Uri1ORCID,Wang Qian H S2,Reiss Ido13

Affiliation:

1. Physics Department, Ben-Gurion University of the Negev, POB 653, Be’er-Sheva 84105, Israel

2. Department of Physics and Astronomy, University of Utah, 201 James Fletcher Bldg., 115 S 1400 E, Salt Lake City, UT 84112, USA

3. Physics Department, Nuclear Research Centre Negev, POB 9001, Be’er-Sheva 84190, Israel

Abstract

ABSTRACT Tangential discontinuities known as cold fronts (CFs) are abundant in groups and clusters of galaxies (GCs). The relaxed, spiral-type CFs were initially thought to be isobaric, but a significant, $10{{\ \rm per\ cent}}$–$20{{\ \rm per\ cent}}$ jump in the thermal pressure Pt was reported when deprojected CFs were stacked, interpreted as missing Pt below the CFs (i.e. at smaller radii r) due to a locally enhanced non-thermal pressure Pnt. We report a significant (∼4.3σ) deprojected jump in Pt across a single sharp CF in the Centaurus cluster. Additional seven CFs are deprojected in the GCs A2029, A2142, A2204, and Centaurus, all found to be consistent (stacked: ∼1.9σ) with similar pressure jumps. Combining our sample with high quality deprojected CFs from the literature indicates pressure jumps at significance levels ranging between 2.7σ and 5.0σ, depending on assumptions. Our nominal results are consistent with Pnt ≃ (0.1–0.3)Pt just below the CF. We test different deprojection and analysis methods to confirm that our results are robust, and show that without careful deprojection, an opposite pressure trend may incorrectly be inferred. Analysing all available deprojected data, we also find: (i) small variations around the mean density and temperature CF contrast q within each GC, monotonically increasing with the GC mass M200 as $q\propto M_{200}^{0.23\pm 0.04}$; (ii) hydrostatic mass discontinuities indicating fast bulk tangential flows below all deprojected CFs, with a mean Mach number ∼0.76; and (iii) the newly deprojected CFs are consistent (stacked: ∼2.9σ) with a $1.25^{+0.09}_{-0.08}$ metallicity drop across the CF. These findings suggest that GCs quite generally harbour extended spiral flows.

Funder

Israel Science Foundation

Israel Atomic Energy Commission

European Commission

Publisher

Oxford University Press (OUP)

Subject

Space and Planetary Science,Astronomy and Astrophysics

Cited by 5 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. The Merger Dynamics of the X-ray- Emitting Plasma in Clusters of Galaxies;Handbook of X-ray and Gamma-ray Astrophysics;2024

2. Radio haloes and relics from extended cosmic-ray ion distributions with strong diffusion in galaxy clusters;Monthly Notices of the Royal Astronomical Society;2023-10-14

3. Quasi-spiral solution to the mixed intracluster medium and the universal entropy profile of galaxy clusters;Monthly Notices of the Royal Astronomical Society;2023-04-07

4. Advection by Large-scale Spiral Flows in Galaxy Clusters;The Astrophysical Journal;2020-06-05

5. The Merger Dynamics of the X-Ray-Emitting Plasma in Clusters of Galaxies;Handbook of X-ray and Gamma-ray Astrophysics;2012-02-24

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3