{ "ABSTRACT ": [ "The spatial distribution of gas matter inside galaxy clusters is not completely smooth, but may host gas clumps associated with substructures. These overdense gas substructures are generally a source of unresolved bias of X-ray observations towards high density gas, but their bright luminosity peaks may be resolved sources within the ICM, that deep X-ray exposures may be (already) capable to detect. In this paper we aim at investigating both features, using a set of high-resolution cosmological simulations with ENZO. First, we monitor how the bias by unresolved gas clumping may yield incorrect estimates of global cluster parameters and affects the measurements of baryon fractions by X-ray observations. We •nd that based on X-ray observations of narrow radial strips, it is dif•cult to recover the real baryon fraction to better than 10 -20 percent uncertainty. Second, we investigated the possibility of observing bright X-ray clumps in the nearby Universe (z 6 0.3). We produced simple mock X-ray observations for several instruments (XMM, Suzaku and ROSAT) and extracted the statistics of potentially detectable bright clumps. Some of the brightest clumps predicted by simulations may already have been already detected in X-ray images with a large •eld of view. However, their small projected size makes it dif•cult to prove their existence based on X-ray morphology only. Preheating, AGN feedback and cosmic rays are found to have little impact on the statistical properties of gas clumps. ", "Key words: galaxy clusters, ICM " ], "1 INTRODUCTION ": [ "The properties of gas matter in more than two-thirds of the galaxy cluster volume are still largely unknown. In order to further improve our use of clusters as high-precision cosmological tools, it is therefore necessary to gain insight into the thermodynamics of their outer regions (see (<>)Ettori & Molendi (<>)2011, and references therein). The surface brightness distribution in clusters outskirts has been studied with ROSAT PSPC (e.g. (<>)Eckert et al. (<>)2012, and references therein) and with Chandra (see (<>)Ettori & Balestra (<>)2009, and references therein). A step forward has been the recent observation of a handful of nearby clusters with the Japanese satellite Suzaku that, despite the relatively poor PSF and small •eld of view of its X-ray imaging spectrometer (XIS), bene•ts from the modest background associated to its low-Earth orbit (see results on PKS0745-191, (<>)George et al. (<>)2009; A2204, (<>)Reiprich et al. (<>)2009; ", "A1795, (<>)Bautz et al. (<>)2009; A1413, (<>)Hoshino et al. (<>)2010; A1689, (<>)Kawaharada et al. (<>)2010; Perseus, (<>)Simionescu et al. (<>)2011; Hydra A, (<>)Sato et al. (<>)2012; see also (<>)Akamatsu & Kawahara (<>)2011). The •rst results from Suzaku indicate a •attening and sometimes even an inversion of the entropy pro•le moving outwards. The infall of cool gas from the large-scale structure might cause the assumption of hydrostatic equilibrium to break down in these regions, which could have important implications on cluster mass measurements ((<>)Rasia et al. (<>)2004; (<>)Lau et al. (<>)2009; (<>)Burns et al. (<>)2010). However, as a consequence of the small •eld of view (and of the large solid angle covered from the bright nearby clusters) observations along a few arbitrarily chosen directions often yield very different results. ", "In addition to instrumental effects (e.g. (<>)Eckert et al. (<>)2011), or non-gravitational effects (e.g. (<>)Roncarelli et al. (<>)2006; (<>)Lapi et al. (<>)2010; (<>)Mathews & Guo (<>)2011; (<>)Battaglia et al. (<>)2010; (<>)Vazza et al. (<>)2012; (<>)Bode et al. (<>)2012), there are •simpler• physical reasons to expect that properties of the ICM derived close to ˘ R200 may be ", "more complex than what is expected from idealized cluster models. ", "One effect is cluster triaxiality and asymmetry, which may cause variations in the ICM properties along directions, due to the presence of large-scale •laments in particular sectors of each cluster (e.g. (<>)Vazza et al. (<>)2011c; (<>)Eckert et al. (<>)2012), or to the cluster-to-cluster variance related to the surrounding environment (e.g. (<>)Burns et al. (<>)2010). ", "A second mechanism related to simple gravitational physics is gas clumping, and its possible variations across different directions from the cluster centre ((<>)Mathiesen et al. (<>)1999; (<>)Nagai & Lau (<>)2011). ", "In general, gas clumping may constitute a source of uncertainty in the derivation of properties of galaxy clusters atmospheres since a signi•cant part of detected photons may come from the most clumpy structures of the ICM, which may not be fully representative of the underlying large-scale distribution of gas (e.g. (<>)Roncarelli et al. (<>)2006; (<>)Vazza et al. (<>)2011c). Indeed, a signi•cant fraction of the gas mass in cluster outskirts may be in the form of dense gas clumps, as suggested by recent simulations ((<>)Nagai & Lau (<>)2011). In such clumps the emissivity of the gas is high, leading to an overestimation of the gas density if the assumption of constant density in each shell is made. The recent results of (<>)Nagai & Lau ((<>)2011) and (<>)Eckert et al. ((<>)2012) show that the treatment of gas clumping factor slightly improves the agreement between simulations and observed X-ray pro•les. ", "The gas clumping factor can also bias the derivation of the total hydrostatic gas mass in galaxy clusters at the ˘ 10 percent level ((<>)Mathiesen et al. (<>)1999), and it may as well bias the projected temperature low ((<>)Rasia et al. (<>)2005). Theoretical models of AGN feedback also suggest that overheated clumps of gas may lead to a more ef•cient distribution of energy within cluster cores ((<>)Birnboim & Dekel (<>)2011). ", "Given that the effect of gas clumping may be resolved or unresolved by real X-ray telescopes depending on their effective resolution and sensitivity, in this paper we aim at addressing both kind of effects, with an extensive analysis of a sample of massive (˘ 1015M⊙) galaxy clusters simulated at high spatial and mass resolution (Sec.(<>)2). First, we study in Sec.(<>)3.1 the bias potentially present in cluster pro“les derived without resolving the gas substructures. Second, in Sec.(<>)3.2 we derive the observable distribution of X-ray bright clumps, assuming realistic resolution and sensitivity of several X-ray telescopes. We test the robustness of our results with changing resolution and with additional non-gravitational processes (radiative cooling, cosmic rays, AGN feedback) in Sec.3.3. Our discussion and conclusions are given in Sec.(<>)4. " ], "2 CLUSTER SIMULATIONS ": [ "The simulations analysed in this work were produced with the Adaptive Mesh Re•nement code ENZO 1.5, developed by the Laboratory for Computational Astrophysics at the University of California in San Diego 1 (<>)(e.g. (<>)Norman et al. (<>)2007; (<>)Collins et al. (<>)2010, and references therein). We simulated twenty galaxy clusters with masses in the range 6 · 1014 6 M/M⊙6 3 · 1015 , extracted from a total cosmic volume of Lbox ˇ 480 Mpc/h. With the use of a nested grid approach we achieved high mass and spatial resolution in the region of cluster formation: mdm = 6.76 · 108M⊙for the ", "Figure 1. 2-dimensional power spectra of X-ray maps for three simulated clusters at z = 0 (E1, E3B and E15B, as in Fig.(<>)2). Only one projection is considered. The long-dashed lines show the power spectra of the total X-ray image of each cluster, while the solid lines show the spectrum of each image after the average X-ray pro•le has been removed. Zero-padding has been considered to deal with the non-periodic domain of each image. The spectra are given in arbitrary code units, but the relative difference in normalization of each cluster spectrum is kept. The vertical grey line shows our •ltering scale to extract X-ray clumps within each image. ", "Table 1. Main characteristics of the simulated clusters at z = 0. Column 1: identi•cation number; 2: total virial mass (Mvir= MDM + Mgas); 3: virial radius (Rv); 4:dynamical classi“cation: RE=relaxing, ME=merging or MM=major merger; 5: approximate redshift of the last merger event. ", "Figure 2. Top panels: X-ray •ux in the [0.5-2] keV (in [erg/(s · cm2)]) of three simulated clusters of our sample at z=0 (E15B-relax, E1-post merger and E3B-merging). Bottom panels: X-ray ”ux of clumps identi“ed by our procedure (also highlighted with white contours). The inner and outer projected area excluded from our analysis have been shadowed. The area shown within each panel is ∼ 3 × 3 R200 for each object. ", "DM particles and ˘ 25 kpc/h in most of the cluster volume inside the •AMR region• (i.e. ˘ 2 − 3 R200 from the cluster centre, see (<>)Vazza et al. (<>)2010; (<>)Vazza (<>)2011a; (<>)Vazza et al. (<>)2011a for further details). ", "We assumed a concordance CDM cosmology, with 0 = 1.0, B = 0.0441, DM = 0.2139,  = 0.742, Hubble parameter h = 0.72 and a normalization for the primordial density power spectrum of ˙8 = 0.8. Most of the runs we present in this work (Sec.3.1-3.2) neglect radiative cooling, star formation and AGN feedback processes. In Sec.3.3, however, we discuss additional runs where the following non-gravitational processes are modelled: radiative cooling, thermal feedback from AGN, and pressure feedback from cosmic ray particles (CR) injected at cosmological shock waves. ", "For consistency with our previous analysis on the same sample of galaxy clusters ((<>)Vazza et al. (<>)2010, (<>)2011a,(<>)c), we divided our sample in dynamical classes based on the total matter accretion history of each halo for z 6 1.0. First, we monitored the time evolution of the DM+gas mass for every object inside the ŽAMR regionŽ in the range 0.0 6 z 6 1.0. Considering a time lapse of t = 1 Gyr, Žmajor mergerŽ events are detected as total matter accretion episode where M(t + t)/M(t) − 1 > 1/3. The systems with a lower accretion rate were further divided by measuring the ratio between the total kinetic energy of gas motions and the ther-", "mal energy inside the virial radius at z = 0, since this quantity parameter provides an indication of the dynamical activity of a cluster (e.g. (<>)Tormen et al. (<>)1997; (<>)Vazza et al. (<>)2006). Using this proxy, we de•ned as •merging• systems those objects that present an energy ratio > 0.4, but did not experienced a major merger in their past (e.g. they show evidence of ongoing accretion with a companion of comparable size, but the cores of the two systems did not encounter yet). The remaining systems were classi•ed as •relaxed•. According to the above classi•cation scheme, our sample presents 4 relaxed objects, 6 merging objects and 10 post-merger objects. ", "Based on our further analysis of this sample, this classi•cation actually mirrors a different level of dynamical activity in the subgroups, i.e. relaxed systems on average host weaker shocks ((<>)Vazza et al. (<>)2010), they are characterized by a lowest turbulent to thermal energy ratio ((<>)Vazza et al. (<>)2011a), and they are characterized by the smallest amount of azimuthal scatter in the gas properties ((<>)Vazza et al. (<>)2011c; (<>)Eckert et al. (<>)2012). In (<>)Vazza et al. ((<>)2011c) the same sample was also divided based on the analysis of the power ratios from the multi-pole decomposition of the X-ray surface brightness images (P3/P0), and the centroid shift (w), as described by (<>)Bohringer¨ et al. ((<>)2010). These morphological parameters of projected X-ray emission maps were measured inside the innermost projected 1 Mpc2 . This leads to decompose our sample into 9 •non-cool-core-like• (NCC) systems, and 11 •cool-core-", "like• systems (CC), once that •ducial thresholds for the two parameters (as in (<>)Cassano et al. (<>)2010) are set. We report that (with only one exception) the NCC-like class here almost perfectly overlap with the class of post-merger systems of (<>)Vazza et al. ((<>)2010), while the CC-like class contains the relaxed and merging classes of (<>)Vazza et al. ((<>)2010). ", "Table 1 lists of all simulated clusters, along with their main parameters measured at z = 0. All objects of the sample have a •nal total mass > 6 · 1014M⊙, 12 of them having a total mass > 1015M⊙. In the last column, we give the classi“cation of the dynamical state of each cluster at z = 0, and the estimated epoch of the last major merger event (for post-merger systems). " ], "2.1 X-ray emission ": [ "We simulated the X-ray •ux (SX) from our clusters, assuming a single temperature plasma in ionization equilibrium within each 3D cell. We use the APEC emission model (e.g. (<>)Smith et al. (<>)2001) to compute the cooling function (T, Z) (where T is the temperature and Z the gas metallicity) inside a given energy band, including continuum and line emission. For each cell in the simulation we assume a constant metallicity of Z/Z⊙= 0.2 (which is a good approximation of the observed metal abundance in cluster outskirts, (<>)Leccardi & Molendi (<>)2008). While line cooling may be to “rst approximation not very relevant for the global description of the hot ICM phase (T ˘ 108K), it may become signi“cant for the emission from clumps, because their virial temperature can be lower than that of the host cluster by a factor ˘ 10. Once the metallicity and the energy band are speci“ed, we compute for each cell the X-ray luminosity, SX= nHne(T, Z)dV , where nHand neare the number density of hydrogen and electrons, respectively, and dV is the volume of the cell. " ], "2.2 De•nition of gas clumps and gas clumping factor ": [ "Although the notion of clumps and of the gas clumping factor is often used in the recent literature, an unambiguous de•nition of this is non-trivial 2 (<>). In this work we distinguish between resolved gas clumps (detected with a •ltering of the simulated X-ray maps) and unresolved gas clumping, which we consider as an unavoidable source of bias in the derivation of global cluster parameters from radial pro•les. On the theoretical point of view, gas clumps represent the peaks in the distribution of the gas clumping factor, and can be identi•ed as single •blobs• seen in projection on the cluster atmosphere if they are bright-enough to be detected. While resolved gas clumps are detected with a 2-dimensional •ltering of the simulated X-ray images (based on their brightness contrast with the smooth X-ray cluster emission), the gas clumping factor is usually estimated in the literature within radial shells from the cluster centre. The two approaches are not fully equivalent, and in this paper we address both, showing that in simple non-radiative runs they are closely related phenomena, and present similar dependence on the cluster dynamical state. " ], "2.2.1 Resolved gas clumps ": [ "We identify bright gas clumps in our cluster sample by post-processing 2-dimensional mock observations of our clusters. We do not consider instrumental effects of real observations (e.g. degrading spatial resolution at the edge of the •eld of view of observation), in order to provide the estimate of the theoretical maximum amount of bright gas clumps in simulations. Instrumental effects depends on the speci•c features of the different telescope, and are expected to further reduce the rate of detection of such X-ray clumps in real observations. In this section we show our simple technique to preliminary extract gas substructures in our projected maps, using a rather large scale (300 kpc/h). •X-ray bright gas clumps•, in our terminology, correspond to the observable part of these substructures, namely their small (6 50 kpc/h) compact core, which may be detected within the host cluster atmosphere according the effective resolution of observations (Sec.(<>)3.2). ", "Based on the literature (e.g. (<>)Dolag et al. (<>)2005, (<>)2009), the most massive substructures in the ICM have a (3-dimensional) linear scale smaller than < 300−500 kpc/h. We investigated the typical projected size of gas substructures by computing the 2-dimensional power spectra of SXfor our cluster images. In order to remove the signal from the large-scale gas atmosphere we subtracted the average 2-dimensional cluster pro“le from each map. We also applied a zero-padding to take into account the non-periodicity of the domain (see (<>)Vazza et al. (<>)2011a and references therein). The results are shown in Fig.(<>)1 for three representative clusters of the sample at z = 0: the relaxed cluster E15B, the post-merger cluster E1 and the merging system E3B-merging (see also Fig.(<>)2). The long-dashed pro“les show the power spectra of the X-ray image of each cluster, while the solid lines show the spectra after the average 2-dimensional pro“le of each image has been removed. The power spectra show that most of the residual substructures in X-ray are characterized by a spatial frequency of k > 10 − 20, corresponding to typical spatial scales l0 < 300 − 600 kpc/h, similar to three-dimensional results ((<>)Dolag et al. (<>)2009). A dependence on the dynamical state of the host cluster is also visible from the power spectra: the post-merger and the merging clusters have residual X-ray emission with more power also on smaller scales, suggesting the presence of enhanced small-scale structures in such systems. We will investigate this issue in more detail in the next sections. ", "To study the •uctuations of the X-ray •ux as a result of the gas clumps we compute maps of residuals with respect to the X-ray emission smoothed over the scale l0. The map of clumps is then computed with all pixels from the map of the residuals, where the condition SX/SX,smooth > is satis“ed. By imposing l0 = 300 kpc/h (˘ 12 cells) and = 2, all evident gas substructures in the projected X-ray images are captured by the algorithm. We veri“ed that the adoption of a larger or a smaller value of l0 by a factor ˘ 2 does not affect our “nal statistics (Sec.(<>)3.2) in a signi“cant way. In Figure (<>)2 we show the projected X-ray ”ux in the [0.5-2] keV energy range from three representative clusters of the sample (E1-post merger, E3B-merging and E15B-relaxed, in the top panels) at z = 0, and the corresponding maps of clumps detected by our “ltering procedure (lower panels). The visual inspection of the maps show that our “ltering procedure ef“ciently removes large-scale “laments around each cluster, and identi“es blob-like features in the projected X-ray map. The relaxed system shows evidence of enhanced gas clumping along its major axis, which is aligned with the surrounding large-scale “laments. Indeed, although this system is a relaxed one based on its X-ray morphology within R200/2 (based on the measure of X-ray morpho-", " s (<>)ss (<>) s s (<>) (<>) s s ss s s ss s s s R500 s s sss s s ss s s s s s sss ss " ], "2.2.2 The gas clumping factor ": [ " s Cρ s s s s ", " ", " s s ss s R ss s s R 25 kpc/h ss ˇ 1.5 R200 s s s s s s s s s ss s ss (<>)s (<>) (<>) (<>) s ss Cρ(R) s s ss s ss s s s s s s s s s s s s (<>) s s s s s ss s s s sss s s s s ss s ss 6 300 kpc/h ss s (<>) s s s ss s s s ss s s s s s s s s s s s s s ss s s s sss ss " ], "3 RESULTS ": [], "3.1 Gas clumping factor from large-scale structures ": [ " s ss s s s ss (<>) (<>) (<>)s (<>) (<>) (<>) (<>) (<>) ", " s s s (<>) ", " ", " ss Cρ(R) sss s s sss s Cρ< 2 ss s s s s Cρ˘ 3 − 5 s R200 s ", "Figure 3. s s s s ss z = 0 s s 1˙ s s sss s s s ss ", "sss s ss s s ss s s ss ss (<>) (<>) s s s s s s (<>) s s s s s s s s s s ss s s sss ", " s s s s s ss ss s s s ss ", " (<>) s s s s s s ˆcr,b < 50 50 6 ˆcr,b < 102 102 6 ˆcr,b < 103 ˆcr,b > 103 ˆcr,b s ˆ/(fbˆcr fb s ˆcr s s s T < 106 106 6 T < 107 107 6 T < 108 T > 108 z = 0 ", " ss s s s s s sss s s s s s s s s s s s sss 6 300 kpc/h s s ss s s s s s s s s (<>) s 1 Mpc/h 3 (<>) (<>) s s s ss ", "Figure 4. Average profiles of gas clumping factor and gas mass distribution for different phases across the whole cluster sample at z = 0, for relaxed clusters (left panels) and for merging clusters (right panels). The average gas clumping factor is computed for different decompositions of the cluster volume in gas­density bins (top 4 panels; lines are colour-coded as described in the legend in the top 2 panels) and temperature bins (bottom 4 panels with colour-coded as detailed in paesl in the third row). The gas over-density is normalized to the cosmological critical baryon density. ", "Figure 5. Top panels s ss s z = 0 s s s s s s s s s ss s Second row s s ss s s s s s s s s s s Third row s s s s s s s Last row s s s ss s s s s s s s s ", "Figure 6. s s s s s ss s ss s Suzaku ROSAT XMM s s s s s ss ", "s s ss s ss s s ss s s s s ss s s sss s s s ss < 106 106 6 T < 107 s s sss s s s s ss s s (<>) s ss ", " s s ˆcr,b < 50 T 6 106 − 107 s s s (<>) (<>) (<>) (<>) (<>) (<>) s s s s s ss s s sss s s s s s s s sss s s ss ss s s (<>) s s ss s s s s s s s s s s s sss (<>)s (<>) s s ss s s s s s s s sss ss s s s s s s ss sss s s ss s ss ss s ss (<>) (<>) s s ˘ Gyr s s ", " s s ss s s (<>) s s s s ss s (<>) s s s s ss s ss s sss s s ss ss s s s s ss s ss ss (<>)s (<>) (<>) (<>) (<>) (<>) s s s s s ss ˘ 500 kpc s ss (<>)s (<>) (<>) (<>) s s ˘ 8 Mpc s s ss s ˘ 20 s s s s s s ", " s s s s (<>) (<>) s R s s s s s 0.02 R200 6 R 6 R200 ", " ss s s s s s 0.8R200 s ˘ R200 s s s ss s s > 0.6R200 s s s s s s s ss s s (<>) ss s s s s s s s s s s (<>) (<>) ", " s s ss s s sss s s (<>) s s s ss ˘ 30 − 40 R200 ss s s s s (<>) s s s > 40 s s ss ", "s s s ss s ss s s s s s s s ss ss (<>)s (<>) (<>) (<>) (<>) (<>) (<>) (<>) ", " (<>) s s Ygas(< R)  fbar(< R)/fb s s fb s s s ", "s s Ygas s s s s s s s s s s s s s s ss sss ss ", " ", "", " ", "", " s s ss (<>) (<>) Yg s s s s R200 s s < 1.2 R200 s ±5 s s ±10 − 20 s ss ", " s s s s s ss s s s s s s ±10 s s s ss s s s ˘ 25 ss s ss ss ss ˘ 10 ˘ 50 ", " ss ss s s ˘ 10 − 20 ss R200 s ˘ 5 ", " ss s s s s s s s s (<>) s s ss s s s s s s s s s s s s ss > 0.4 R200 s s ", " s s Cρ˘ 2 − 3 s ss s s s s ss sss s s s s s s s s s s ss s s s s s s s s s s s s s ss ss s s s s ss s s s ss s s s s ss s s ss s ", "s s s s s s s s s ss s > 0.4R200 s s s ss s s ˘ 5−10 s s s ", "s s s s s larger s ˘ R200 s ss (<>)s (<>) smaller s s ss (<>) (<>) s ss (<>) (<>) (<>) (<>) s ss s s ss s s s ±10 − 20 s ", " sss s ss lower ˘ 30 − 40 s s ss s s s s s s s ss sss (<>) (<>) (<>) (<>) s ss s s s ss s s s s s lower s R ss s s s s s s s s (<>) (<>) s s s ss ", "Figure 8. s s s s s ss SX,low = 2·10−15 erg/(s·cm 2) ′′ s s ≈ 10 s XMM s s s s s ss s s s s s ss ss s ss s s s s ss ", "ss (<>) (<>) (<>) (<>) s s s s (<>) (<>) s s (<>) (<>) ss s s s s s ss s s s ss s s s " ], "3.2 Properties of gas clumps ": [ " ss s s s s s s s (<>) s s s sss ss s s s s ss s ss z = 04 (<>) z = 0.1 z = 0.3 s / (1 + z)4 s s s s s s ss ss SX,low s s s ss s ss s s ss s s s (<>)Rs (<>) (<>) (<>) (<>) (<>) s s s ssss s s s s s s s s ss ss s s s ss s s s s s s ", " s s ss sss s s s s s (<>) s s s s ss s ss s s s s ss SX,low = 2 · 10−15erg/(s · cm2) XMM ss SX,low = 3 · 10−14erg/(s · cm2) ROSAT ss SX,low = 10−13erg/(s · cm2) Suzaku ss s s ss s XMM s s ss s s s s s s s s s s s s s s ", "s ss s s ss ss ˘ 20 − 30 s ROSATSuzaku ˘ 102 s XMM s ss s ss s the whole s s 1.2 × 1.2 R200 s s s ˘ 2 − 3 s s s s s s z = 0.3 XMM ss s s s ˘ 30 s s s s s s ss s ˘ 5 · 10−12erg/(s · cm2) Suzaku ROSAT ˘ 10−12erg/(s · cm2) XMM 5 (<>) ", " s ss s ", "Figure 7. s s s s s ss SX,low = 2 · 10−15erg/(s · cm2) s ≈ 10 ′′ s XMM s s s s s s s s s s s s sss s s ss s ss s s ss s s sss ", "z = 0.1 ss XMM s ss ss s ", " (<>) s s s s s s s ss s SX6(<>) s s s s s s s ", " s ss s s ", " s s s s ss s s s s ˘ 2−3 s ss ˘ 2 − 4 ss s ss s s s s sss ˘ 2 s sss s s s s s ss s ss s s s s s s s s s s s s s s s s s (<>) (<>) s s s s 6 50 kpc/h s s s s s ss s s s s s s s ss s ", " (<>) s s s s s ss s s s 0.6 6 R/R200 6 1.2 s > 70 s s s s s s s ", "Figure 11. s s s s s s s ss R s (<>) (<>) s s s ss s 0.1 6 R/R200 < 0.6 s s s s s 0.6 6 R/R200 < 1.2 s s s ss s ss ", " s s s ss s s s s sss ss ss ", " s ss s ss XMM Suzaku ROSAT Chandra ss s (<>) " ], "3.3 Tests with additional physics and at higher resolution ": [ " s s s s ss s ", "(<>) (<>) s s ss s s s s s s s s (<>) (<>) R s s s s s s s s s sss s s s s s s ss ss s ss s (<>) (<>) ", " s s ssss ss s s s ss ss s s s s sss s ss s s ˘ 3 − 4 · 104 s s s s s s ss s s s ss (<>) (<>) s ss ss ˘ 2 − 3 · 1014M⊙ ss s s s s s s ss s ss s s 25 kpc/h s s s s z = 1 Wjet ˇ 1044erg/s s s 100 keVcm2 s z = 10 s s z = 1 Wjet ˇ 1043erg/s s ss ss s s s s 12 kpc/h ", " ss (<>) (<>) s s s (<>) (<>) s s ss s s s s s s s s ss (<>) (<>) s s ss s s s s sss sss s s s s s ss s s s ss s s sss s (<>) (<>) s s s s ˘ 2 s s s s s 0.1R200 ss s s s s s ", " s s s s (<>) (<>) s s s s (<>) s (<>) s ss s ", "Figure 9. s log10LX s ss ∼ 3 · 1014M⊙ s s s s s ss s s ", "Rs Ł = 4/3 ss s s s s s s s ss ss (<>) s (<>) ss Rs s s s s ˘ 0.05 − 0.1 s R200 s ss z = 0 ", " s sss ss s s s (<>) ss (<>) (<>) (<>) (<>)s (<>) s s s ss ss s s ", " (<>) ss s ss s ss s ", " s s s s s s s s s s (<>) s s s ss s ss s s s ss s s s s s s s s s 6 0.3R200 s s s s s s s 10 − 102 s s s s ss ss s ss s s ", " s s s R s ss s s sss s s s ss Rs s ss R s ˘ 10 − 20 s s s s ss s s Rs s s s s (<>) sss s s Rs ss s ss ", " s s s s s s s s s s s ssss s s s s s s s s ss s s s s s sss s s (<>)R (<>) s s s s s ss s ˘ R200 z = 0 s s s ss s s sss s ss ss s ss s s s s s s s s s s s s s s s s s ", "Figure 10. s s s ss ∼ 2 − 3 · 1014M⊙s s s s s s s R s s s s s s s ", "s s s s s s s sss s s s ss ss s ˘ 2 − 3 s s s s s s s (<>) s 6 50 kpc/h s s s s s s s s s s s s s s ", " s s s s ss s ss (<>) (<>) s s s s s ss ss s s s s ", " s ss s s s s sss s s s s unresolved s s ss ss " ], "4 DISCUSSION AND CONCLUSIONS ": [ " s s s s s ss ss ss sss s s s sss s ss s s sss s s ss s ss ss ss s ", " s ss s ss ", " s s s ss sss ˘ 1015M⊙ s s (<>) (<>) (<>)s (<>) s s s s ss s s s s s ss (<>) (<>) s ss s s s ss C(ˆ) ˘ 3 − 5 s sss sss s sss s s s ss ss s s s s s ss s ss s s sss s s s s s s s ss s s s ss s s s s s s s ±10 sss ±20 sss s ss ss ss s ", " s s s s s s ss ss s s s s s s s s ss s s s s s s s s s s s s s s s ss s ss s s s s ss s sss s s s s s s s sss s ˘ 2 − 10 s ss s sss s s ss s s s ss s ˘ 0.3 s s 0.6 6 R/R200 6 1.2 s s s s s < 0.6R/R200 s s s s s 6 50 ss s ss s ss s Rss s s ss s s s R ss s s (<>) (<>) s ss s s s sss s ss s s s s s s s ss s ˘ 2 − 3 s ssss s ss ss s s ", "s s s s 6 50 kpc/h ", " s ss sss s (<>) ss s s ss R ss sss s ss s s ss s s s s < 50 kpc/h s ss s ss s s ", " s ss ss R ss (<>) (<>) (<>) s s s ss R s s s sss s s s s s s s s ss s 0.1 6 R/R200 < 0.6 0.6 6 R/R200 < 1.2 ", " ss s s ˘ 1.5 − 2 s s s s s s s s s s ss ss s s s ss s s s s s s s s s ss ss s s s s s s ss s s s s ss ss R s (<>) (<>) s s s sss ss R ss s s s ss ss ˘ 3 · 10−14erg/(s · cm2) s ˘ 20/2 s ss R (<>) (<>) s (<>) (<>) ss s ˘ 6 − 8 s R200 s s ss s s ˘ 40 R200 s s s s s s s s s (<>) (<>) (<>)s (<>) s ss s s s ", " s ss s s ss s s s ss s s s s s s Chandra s ss s ss s s s s s s s s s s s s s ss ss s s ss s s s s 6 100 − 200 kpc s Chandra ss (<>)s (<>) ", " ss s s s s s s " ], "ACKNOWLEDGEMENTS ": [ " s s s s R s sss s ss s s s s s s s s s s ss s s s " ] }