A Baryonic Effect on the Merger Timescale of Galaxy Clusters

Zhang, Congyao; Yu, Qingjuan; Lu, Youjun

doi:10.3847/0004-637x/820/2/85

Cited by 24 publications

(31 citation statements)

References 47 publications

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“…For the entire sample (left panel), the correlation is strongest for a i = 0.7 at all measured radii, which means that mass accretion in the interval of 0.7 < a < 1.0 leaves the strongest imprint on the ICM shape. The lookback time corresponding to this interval is ≈ 4.54 Gyrs, which is close to post-merger dynamical relaxation time of gas motions predicted by simulations (Nelson et al 2012(Nelson et al , 2014bZhang et al 2016). The ICM shape does not retain as much Figure 5.…”

Section: Correlation Between the Mar And Icm Ellipticitysupporting

confidence: 81%

Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

Chen

Avestruz

Kravtsov

et al. 2019

Monthly Notices of the Royal Astronomical Society

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We use a statistical sample of galaxy clusters from a large cosmological N-body+hydrodynamics simulation to examine the relation between morphology, or shape, of the X-ray emitting intracluster medium (ICM) and the mass accretion history of the galaxy clusters. We find that the mass accretion rate (MAR) of a cluster is correlated with the ellipticity of the ICM. The correlation is largely driven by material accreted in the last ∼ 4.5 Gyr, indicating a characteristic time-scale for relaxation of cluster gas. Furthermore, we find that the ellipticity of the outer regions (R ∼ R 500c ) of the ICM is correlated with the overall MAR of clusters, while ellipticity of the inner regions ( 0.5R 500c ) is sensitive to recent major mergers with mass ratios of ≥ 1 : 3. Finally, we examine the impact of variations in cluster mass accretion history on the X-ray observable-mass scaling relations. We show that there is a continuous anti-correlation between the residuals in the T X − M relation and cluster MARs, within which merging and relaxed clusters occupy extremes of the distribution rather than form two peaks in a bi-modal distribution, as was often assumed previously. Our results indicate the systematic uncertainties in the X-ray observable-mass relations can be mitigated by using the information encoded in the apparent ICM ellipticity.

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Section: Correlation Between the Mar And Icm Ellipticitysupporting

confidence: 81%

Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

Chen

Avestruz

Kravtsov

et al. 2019

Monthly Notices of the Royal Astronomical Society

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“…The value is consistent with that obtained from our data. This is slower than those of 2002cx (0.012 mag day These late phase decline rates of SNe Iax except for SN 2014dt are similar to that of a normal SN Ia SN 2011fe, which is 0.0151 mag day −1 at 100 -300 days (Zhang et al 2016). SN 2014dt shows the slowest decline among SNe Ia and Iax.…”

Section: Light Curvesmentioning

confidence: 64%

Extended optical/NIR observations of Type Iax supernova 2014dt: Possible signatures of a bound remnant

Kawabata

Maeda

et al. 2018

Publications of the Astronomical Society of Japan

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We present optical and near-infrared observations of the nearby Type Iax supernova (SN) 2014dt from 14 to 410 days after the maximum light. The velocities of the iron absorption lines in the early phase indicated that SN 2014dt showed slower expansion than the well-observed Type Iax SNe 2002cx, 2005hk and 2012Z. In the late phase, the evolution of the light curve and that of the spectra were considerably slower. The spectral energy distribution kept roughly the same shape after ∼ 100 days, and the bolometric light curve flattened during the same period. These observations suggest the existence of an optically thick component that almost fully trapped the γ-ray energy from 56 Co decay. These findings are consistent with the predictions of the weak deflagration model, leaving a bound white dwarf remnant after the explosion.

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“…We have explored the cluster merger process for a wide range of merger parameters in our previous works (see e.g. Zhang et al 2014Zhang et al , 2016) 5 , which provided some intuitions on this question. For example, Zhang et al (2019a) and Lyskova et al (2019) presented analysis of two merging systems with ξ = 10 and zero and large impact parameters respectively.…”

Section: Key Parameters γ and Mrs Shaping Ma-shocksmentioning

confidence: 99%

Encounters of merger and accretion shocks in galaxy clusters and their effects on intracluster medium

Zhang

Churazov

Dolag

et al. 2020

Monthly Notices of the Royal Astronomical Society

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Several types/classes of shocks naturally arise during formation and evolution of galaxy clusters. One such class is represented by accretion shocks, associated with deceleration of infalling baryons. Such shocks, characterized by a very high Mach number, are present even in 1D models of cluster evolution. Another class is composed of "runaway merger shocks", which appear when a merger shock, driven by a sufficiently massive infalling subcluster, propagates away from the main-cluster center. We argue that, when the merger shock overtakes the accretion shock, a new long-living shock is formed that propagates to large distances from the main cluster (well beyond its virial radius) affecting the cold gas around the cluster. We refer to these structures as Merger-accelerated Accretion shocks (MA-shocks) in this paper.We show examples of such MA-shocks in 1D and 3D simulations and discuss their characteristic properties. In particular, (1) MA-shocks shape the boundary separating the hot intracluster medium (ICM) from the unshocked gas, giving this boundary a "flower-like" morphology. In 3D, MA-shocks occupy space between the dense accreting filaments.(2) Evolution of MA-shocks highly depends on the Mach number of the runaway merger shock and the mass accretion rate parameter of the cluster. (3) MA-shocks may lead to the misalignment of the ICM boundary and the splashback radius.(racc rsp) if the gas adiabatic index is γ = 5/3 (see e.g. Shi 2016b) 1 .However, the evolution of galaxy clusters is more complicated than those one-dimensional (1D) self-similar solutions. Two major processes tend to break the self-similarity (and also spherical symmetry) of galaxy clusters, i.e. active galactic nucleus (AGN) feedback (see e.g. Werner et al. 2019, for a recent review) and cluster mergers (e.g. Sarazin 2002). The former process perturbs the gas in cluster cores (e.g. 100 kpc); the latter one, 1 Specifically, the alignment of the racc and rsp holds when γ = 5/3 only if the cluster mass accretion rate parameter (Γ) is in the range of 0.5 ≤ Γ ≤ 5 (Shi 2016b; see the definition of Γ in Section 2).

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A Baryonic Effect on the Merger Timescale of Galaxy Clusters

Cited by 24 publications

References 47 publications

Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

Extended optical/NIR observations of Type Iax supernova 2014dt: Possible signatures of a bound remnant

Encounters of merger and accretion shocks in galaxy clusters and their effects on intracluster medium

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