Little evidence for entropy and energy excess beyond <i>r</i>500 - An end to ICM preheating?

Iqbal, Asif; Majumdar, Subhabrata; Nath, Biman B.; Ettori, S.; Eckert, D.; Malik, Manzoor Ahmad

doi:10.1093/mnrasl/slw220

“…This paper is a continuation of our recent work Iqbal et al (2017) wherein we showed that pre-heating scenarios are ruled out at more than 3σ statistical level. In this work, we present a detailed study of the excess entropy profiles along with feedback energy profiles and discuss the effect of non-thermal pressure and clumping in our estimates.…”

Section: Introductionsupporting

confidence: 64%

Excess entropy and energy feedback from within cluster cores up to r$_{200}$

Iqbal,

Majumdar,

Nath

et al. 2017

Preprint

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We estimate the "non-gravitational" entropy-injection profiles, ∆K, and the resultant energy feedback profiles, ∆E, of the intracluster medium for 17 clusters using their Planck SZ and ROSAT X-Ray observations, spanning a large radial range from 0.2r 500 up to r 200 . The feedback profiles are estimated by comparing the observed entropy, at fixed gas mass shells, with theoretical entropy profiles predicted from non-radiative hydrodynamic simulations. We include non-thermal pressure and gas clumping in our analysis. The inclusion of non-thermal pressure and clumping results in changing the estimates for r 500 and r 200 by 10%-20%. When clumpiness is not considered it leads to an under-estimation of ∆K ≈ 300 keV cm 2 at r 500 and ∆K ≈ 1100 keV cm 2 at r 200 . On the other hand, neglecting non-thermal pressure results in an over-estimation of ∆K ≈ 100 keV cm 2 at r 500 and under-estimation of ∆K ≈ 450 keV cm 2 at r 200 . For the estimated feedback energy, we find that ignoring clumping leads to an underestimation of energy per particle ∆E ≈ 1 keV at r 500 and ∆E ≈ 1.5 keV at r 200 . Similarly, neglect of the non-thermal pressure results in an over-estimation of ∆E ≈ 0.5 keV at r 500 and under-estimation of ∆E ≈ 0.25 keV at r 200 . We find entropy floor of ∆K ≈ 300 keV cm 2 is ruled out at ≈ 3σ throughout the entire radial range and ∆E ≈ 1 keV at more than 3σ beyond r 500 , strongly constraining ICM pre-heating scenarios. We also demonstrate robustness of results w.r.t sample selection, X-Ray analysis procedures, entropy modeling etc.

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“…We therefore, incorporate both these factors in our calculations. This paper is a continuation of our recent work Iqbal et al (2017) wherein we showed that pre-heating scenarios are ruled out at more than 3σ statistical level. In this work, we present a detailed study of the excess entropy profiles along with feedback energy profiles and discuss the effect of non-thermal pressure and clumping in our estimates.…”

supporting

confidence: 64%

Excess entropy and energy feedback from within cluster cores up to r200

Iqbal

¹

,

Majumdar²,

Nath

³

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

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We estimate the "non-gravitational" entropy-injection profiles, ∆K, and the resultant energy feedback profiles, ∆E, of the intracluster medium for 17 clusters using their Planck SZ and ROSAT X-Ray observations, spanning a large radial range from 0.2r 500 up to r 200 . The feedback profiles are estimated by comparing the observed entropy, at fixed gas mass shells, with theoretical entropy profiles predicted from non-radiative hydrodynamic simulations. We include non-thermal pressure and gas clumping in our analysis. The inclusion of non-thermal pressure and clumping results in changing the estimates for r 500 and r 200 by 10%-20%. When clumpiness is not considered it leads to an under-estimation of ∆K ≈ 300 keV cm 2 at r 500 and ∆K ≈ 1100 keV cm 2 at r 200 . On the other hand, neglecting non-thermal pressure results in an over-estimation of ∆K ≈ 100 keV cm 2 at r 500 and under-estimation of ∆K ≈ 450 keV cm 2 at r 200 . For the estimated feedback energy, we find that ignoring clumping leads to an underestimation of energy per particle ∆E ≈ 1 keV at r 500 and ∆E ≈ 1.5 keV at r 200 . Similarly, neglect of the non-thermal pressure results in an over-estimation of ∆E ≈ 0.5 keV at r 500 and under-estimation of ∆E ≈ 0.25 keV at r 200 . We find entropy floor of ∆K ≈ 300 keV cm 2 is ruled out at ≈ 3σ throughout the entire radial range and ∆E ≈ 1 keV at more than 3σ beyond r 500 , strongly constraining ICM pre-heating scenarios. We also demonstrate robustness of results w.r.t sample selection, X-Ray analysis procedures, entropy modeling etc.

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“…The preheating scenario has been directly challenged recently by the findings of Iqbal et al (2017), which in a study of the outskirts of a large sample of clusters, ruled out evidence for non-gravitational preheating to high significance. Focusing on more evolved clusters, the simulations of Guo & Mathews (2010) show that AGN outbursts of extreme energies (10 62 erg) similar to those seen in RX J1532.9+3021 (Hlavacek-Larrondo et al 2013) and MACS J1931.8-2634 (Ehlert et al 2011) would be capable of destroying more established SCCs in the low-z universe.…”

Section: Introductionmentioning

confidence: 99%

The Megaparsec-scale Gas-sloshing Spiral in the Remnant Cool Core Cluster Abell 1763

Douglass

¹

,

Blanton

²

,

Randall

³

et al. 2018

ApJ

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We present a multiwavelength study of the massive galaxy cluster Abell 1763 at redshift z = 0.231. Image analysis of a 19.6 ks Chandra archival observation reveals a cluster-wide spiral of enhanced surface brightness in the intracluster medium (ICM). While such spirals are understood to form in clusters with sloshing strong cool cores (SCCs), the gas comprising the spiral's apex is of intermediate entropy (∼ 110 keV cm 2 ) and cooling time (∼ 6.8 Gyr), indicating core disruption is occurring throughout the spiral formation process. Two subclusters dominated by the secondand third-ranked galaxies in the system lie along a line parallel to the elongation axis of the primary cluster's ICM. Both subsystems appear to have fallen in along a previously discovered intercluster filament and are each considered candidates as the perturber responsible for initiating disruptive core sloshing. Dynamical analysis indicates infall is occurring with a relative radial velocity of ∼ 1800 km s −1 . The brightest cluster galaxy of Abell 1763 possesses a high line-of-sight peculiar velocity (v pec ∼ 650 km s −1 ) and hosts a powerful (P 1.4 ∼ 10 26 W Hz −1 ) bent double-lobed radio source, likely shaped by the relative bulk ICM flow induced in the merger. The cluster merger model of SCC destruction invokes low impact parameter infall as the condition required for core transformation. In contrast to this, the high angular momentum event occurring in Abell 1763 suggests that off-axis mergers play a greater role in establishing the non-cool core cluster population than previously assumed.

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Little evidence for entropy and energy excess beyond r500 - An end to ICM preheating?

Cited by 8 publications

References 48 publications

Excess entropy and energy feedback from within cluster cores up to r$_{200}$

Excess entropy and energy feedback from within cluster cores up to r$_{200}$

Excess entropy and energy feedback from within cluster cores up to r200

The Megaparsec-scale Gas-sloshing Spiral in the Remnant Cool Core Cluster Abell 1763

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