Investigating AGN heating in a sample of nearby clusters

By R. Dunn, A. C. Fabian. 2006

207 citations recorded by the source corpus.

We analyse those objects in the Brightest 55 sample of clusters of galaxies which have a short central cooling time and a central temperature drop. Such clusters are likely to require some form of heating. Where clear radio bubbles are observed in these clusters, their energy injection is compared to the X-ray cooling rate. Of the 20 clusters requiring heating, at least 14 have clear bubbles, implying a duty cycle for the bubbling activity of at least 70 per cent. The average distance out to which the bubbles can offset the X-ray cooling, r heat , is given by r heat /r cool = 0.86 ± 0.11 where r cool is defined as the radius as which the radiative cooling time is 3 Gyr. 10 out of 16 clusters have r hcat /r cool ? 1, but there is a large range in values. The clusters which require heating but show no clear bubbles were combined with those clusters which have a radio core to form a second subsample. Using r heat = 0.86r cool we calculate the size of an average bubble expected in these clusters. In five cases (3C129.1, A2063, A2204, A3112 and A3391) the radio morphology is bi-lobed and its extent similar to the expected bubble sizes. A comparison between the actual bubble size and the maximum expected if they were to offset the X-ray cooling exactly, R max , shows a peak at R bubble ∼ 0.7R max with a tail extending to larger R bubble /R max . The offset from the expected value of R bubble ∼ R max may indicate the presence of a non-thermal component in the innermost intracluster medium of most clusters, with a pressure comparable to the thermal pressure.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/e0d8ee2567642a23fc127e57a9a14911a650371b

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Citations in the corpus

A unified model for AGN feedback in cosmological simulations of structure formation (2007, background): “Indeed, a number of observational studies (e.g. De Grandi & Molendi, 2002; Vikhlinin et al., 2005; Dunn & Fabian, 2006; Pratt et al., 2007) have shown that the central temperature profiles of relaxed, cool core clusters decrease with decreasing radius, while at the same time these systems require…”
A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies. II. Formation of Red Ellipticals (2007, background): “…of feedback, including, for example, the inflation of radio bubbles in clusters at relatively low accretion rates (e.g., Fabian et al. 2006; Dunn & Fabian 2006; Allen et al. 2006b; Sanders & Fabian 2007 and references therein) but also the driving of weak winds from radiatively inefficient…”
A deeper X‐ray study of the core of the Perseus galaxy cluster: the power of sound waves and the distribution of metals and cosmic rays (2007, methodology): “This is then compared with the power radiated within the inner regions of the cluster core where the radiative cooling time is shorter than its expected age of a few Gyr (by age in this context we mean the time since the last major merger).”
The Coevolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe (2014, background): “Bubbles and cavities in the X-ray gas are also seen in a high percentage of clusters, reaching nearly 100% in those clusters with cooling times below 3 Gyr (Dunn & Fabian 2006, Fabian 2012).”
Mechanical AGN feedback: controlling the thermodynamical evolution of elliptical galaxies (2012, background): “In galaxy clusters the detection fraction rises to 2/3 (Dunn & Fabian 2006).”
LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations (2008, methodology): “Similar studies for nearby clusters based on Chandra data can be found in Sanderson et al. (2006) and Dunn & Fabian (2006).”
What is a cool-core cluster? a detailed analysis of the cores of the X-ray flux-limited HIFLUGCS cluster sample (2009, background): “On the observational side recent studies (e.g. Bı̂rzan et al. 2004; Rafferty et al. 2006; Dunn & Fabian 2006, 2008; Bı̂rzan et al. 2008) have looked at the mechanical energy released by AGN driven bubbles and compared it to the energy needed to quench the CF.”
Radiative efficiency, variability and Bondi accretion on to massive black holes: the transition from radio AGN to quasars in brightest cluster galaxies (2012, background): “For complete samples of clusters, the fraction with detected X-ray cavities implies a duty cycle of at least∼ 60−70 per cent (Dunn & Fabian 2006; Bı̂rzan et al. 2009; Bı̂rzan et al. 2012).”
Simulating galaxy formation with black hole driven thermal and kinetic feedback (2016, background): “Previous works (Sijacki et al. 2007, 2015) have employed a fixed value of χ. Black holes at low redshift located in massive systems show clear signatures of being in a ‘radio’ feedback state, (Dunn & Fabian 2006) which indicates low Eddington ratios.”
Heating Hot Atmospheres with Active Galactic Nuclei (2007, methodology): “The trend in Figure 8 does not take account of the 30% of cooling flow clusters that lack identifiable cavities (Dunn & Fabian 2006), which would in principle populate the lower right-hand side of the diagram.”
AGN heating and ICM cooling in the HIFLUGCS sample of galaxy clusters (2008, background): “This is consistent with the result of Dunn & Fabian (2006), who analyzed a low-redshift sample of clusters (B55) selected from pre-ROSAT data.”
A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei (2008, background): “Intriguingly, the majority of cooling flow clusters host these active radio galaxies at their centres (Dunn & Fabian 2006, 2008), and X-ray maps reveal that the radio lobes are often spatially coincident with cavities, thought to be bubbles filled with relativistic plasma and inflated by the jets…”