Stable Heating of Cluster Cooling Flows by Cosmic-Ray Streaming

Fujita, Yutaka; Ohira, Yutaka

doi:10.1088/0004-637x/738/2/182

Cited by 39 publications

(34 citation statements)

References 80 publications

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“…For the radial dependence of the CR density, we first assume that the CR follow the same radial distribution as the thermal gas (referred to as the "isobaric" case). As alternative possibilities, we also consider a profile where the CR-to-thermal energy ratio increases with radius as ǫ(r) ∼ r 0.5 (referred as "flatter"), as expected from the acceleration of CR at cosmological shocks (see e.g., Vazza et al 2012;Pinzke & Pfrommer 2010;Donnert et al 2010), and a decreasing radial profile (ǫ(r) ∼ r −0.5 , referred as "steeper") to model the injection of CR by a central AGN (e.g., Colafrancesco & Marchegiani 2008;Mathews 2009;Fujita & Ohira 2011). Finally, upper limits on the CR energy density were derived for the three different cases and compared with the average thermal energy in our population, which was computed using the parameters given in Chen et al (2007).…”

Section: Methodsmentioning

confidence: 99%

“…While the general picture is clear, the details of the heat transfer mechanism are still not understood. One of the proposed mechanisms (e.g., Colafrancesco & Marchegiani 2008;Mathews 2009;Fujita & Ohira 2011) considers the interaction of a population of relativistic CR with the gas as heat conveyor. In this framework, it has been shown that the observed Xray properties can be recovered if the CR energy density is large enough.…”

Section: Agn Feedback In Cool-core Clustersmentioning

confidence: 99%

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Probing the cosmic-ray content of galaxy clusters by stackingFermi-LAT count maps

Huber

Tchernin

Eckert

et al. 2013

A&A

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Aims. Observation in radio have shown that galaxy clusters are giant reservoirs of cosmic rays (CR). Although a gammaray signal from the cluster volume is expected to arise through interactions of CR protons with the ambient plasma, a confirming observation is still missing. Methods. We search for a cumulative gamma-ray emission in direction of galaxy clusters by analysing a collection of stacked Fermi-LAT count maps. Additionally, we investigate possible systematic differences in the emission between cool-core and non-cool core cluster populations. Results. Making use of a sample of 53 clusters selected from the HIFLUGCS catalog, we do not detect a significant signal from the stacked sample. The upper limit on the average flux per cluster derived for the total stacked sample is at the level of a few 10 −11 ph cm −2 s −1 at 95% confidence level in the 1-300 GeV band, assuming power-law spectra with photon indices 2.0, 2.4, 2.8 and 3.2. Separate stacking of the cool core and non-cool core clusters in the sample lead to similar values of around 5 × 10 −11 ph cm −2 s −1 and 2 × 10 −11 ph cm −2 s −1 , respectively. Conclusions. Under the assumption that decaying π 0 , produced in collisions between CRs and the ambient thermal gas, are responsible for the gamma-ray emission, we set upper limits on the average CR content in galaxy clusters. For the entire cluster population, our upper limit on the gamma-ray flux translates into an upper limit on the average CR-to-thermal energy ratio of 4.6% for a photon index of 2.4, although it is possible for individual systems to exceed this limit. Our 95% upper limits are at the level expected from numerical simulations, which likely suggests that the injection of CR at cosmological shocks is less efficient than previously assumed.

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Section: Methodsmentioning

confidence: 99%

Section: Agn Feedback In Cool-core Clustersmentioning

confidence: 99%

Probing the cosmic-ray content of galaxy clusters by stackingFermi-LAT count maps

Huber

Tchernin

Eckert

et al. 2013

A&A

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“…Cosmic rays (CRs) can provide additional pressure support to gas, drive galactic outflows, and heat the CGM/ICM directly via hadronic and streaming losses (Guo & Oh 2008;Sharma et al 2010;Enßlin et al 2011;Fujita & Ohira 2011;Wiener et al 2013;Fujita et al 2013;Ruszkowski et al 2017a,b;Pfrommer 2013;Pfrommer et al 2017a;Jacob & Pfrommer 2017a,b;Jacob et al 2018). As a result several of the studies above suggest they can help quench star formation; however this is usually in the context of CRs from AGN.…”

Section: Cosmic Rays (Not From Agn)mentioning

confidence: 99%

The failure of stellar feedback, magnetic fields, conduction, and morphological quenching in maintaining red galaxies

Hopkins

Hayward

et al. 2019

Monthly Notices of the Royal Astronomical Society

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The quenching "maintenance" and related "cooling flow" problems are important in galaxies from Milky Way mass through clusters. We investigate this in halos with masses ∼ 10 12 − 10 14 M , using non-cosmological high-resolution hydrodynamic simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model. We specifically focus on physics present without AGN, and show that various proposed "non-AGN" solution mechanisms in the literature, including Type Ia supernovae, shocked AGB winds, other forms of stellar feedback (e.g. cosmic rays), magnetic fields, Spitzer-Braginskii conduction, or "morphological quenching" do not halt or substantially reduce cooling flows nor maintain "quenched" galaxies in this mass range. We show that stellar feedback (including cosmic rays from SNe) alters the balance of cold/warm gas and the rate at which the cooled gas within the galaxy turns into stars, but not the net baryonic inflow. If anything, outflowing metals and dense gas promote additional cooling. Conduction is important only in the most massive halos, as expected, but even at ∼ 10 14 M reduces inflow only by a factor ∼ 2 (owing to saturation effects and anisotropic suppression). Changing the morphology of the galaxies only slightly alters their Toomre-Q parameter, and has no effect on cooling (as expected), so has essentially no effect on cooling flows or maintaining quenching. This all supports the idea that additional physics, e.g., AGN feedback, must be important in massive galaxies.

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“…Similarly, strong shocks are produced in jets from active galactic nuclei and they release large amounts of CRs as observed in radio emission (Fanaroff & Riley 1974;Pierre Auger Collaboration et al 2007;Croston et al 2009), and help to release the feedback back to the hot gas from galaxy clusters (Croston et al 2008;Guo & Oh 2008;Sijacki et al 2008;Guo & Mathews 2011;Fujita & Ohira 2011;Jacob & Pfrommer 2017;Ruszkowski et al 2017a;Ehlert et al 2018). However, again, their impact might significantly differ depending onto which CR dynamical processes are modeled and ignored.…”

Section: Introductionmentioning

confidence: 99%

Shock-accelerated cosmic rays and streaming instability in the adaptive mesh refinement code Ramses

Dubois

Commerçon

Marcowith

et al. 2019

A&A

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Cosmic rays (CRs) are supposed to play a dynamical important role on several key aspects of galaxy evolution, including the structure of the interstellar medium, the formation of galactic winds, and the non-thermal pressure support of halos. We introduce a numerical model solving for the CR streaming instability and acceleration of CRs at shocks with a fluid approach in the adaptive mesh refinement code ramses. CR streaming is solved with a diffusion-like approach and its anisotropic nature is naturally captured. We introduce a shock finder for the ramses code that automatically detects shock discontinuities in the flow. Shocks are the loci for CR injection, and their efficiency of CR acceleration is made dependent of the upstream magnetic obliquity according to the diffuse shock acceleration mechanism. We show that the shock finder accurately captures shock locations and estimates the shock Mach number for several problems. The obliquity-dependent injection of CRs in the Sedov solution leads to situations where the supernova bubble exhibits large polar caps (homogeneous background magnetic field), or a patchy structure of the CR distribution (inhomogeneous background magnetic field). Finally, we combine both accelerated CRs with streaming in a simple turbulent interstellar medium box, and show that the presence of CRs significantly modify the structure of the gas.

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Stable Heating of Cluster Cooling Flows by Cosmic-Ray Streaming

Cited by 39 publications

References 80 publications

Probing the cosmic-ray content of galaxy clusters by stackingFermi-LAT count maps

Probing the cosmic-ray content of galaxy clusters by stackingFermi-LAT count maps

The failure of stellar feedback, magnetic fields, conduction, and morphological quenching in maintaining red galaxies

Shock-accelerated cosmic rays and streaming instability in the adaptive mesh refinement code Ramses

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