Bubbles as tracers of heat input to cooling flows

Binney, James; Bibi, F. Alouani; Omma, Henrik

doi:10.1111/j.1365-2966.2007.11575.x

Cited by 33 publications

(28 citation statements)

References 27 publications

(34 reference statements)

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“…They include only the energy associated with inflating the bubbles, while significant energy can also be dissipated through sound waves, viscosity and weak shocks (McNamara et al 2005; Nulsen et al 2005a,b; Fabian et al 2006; Forman et al 2007). Binney, Bibi & Omma (2007) analysed 3D adaptive grid simulations of heating of cooling flows, and found that the bubbles reflected only ∼10 per cent of the total injected energy.…”

Section: Resultsmentioning

confidence: 99%

A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei

Somerville

Hopkins

Cox

et al. 2008

Monthly Notices of the Royal Astronomical Society

1,141

1,441

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We present a new semi‐analytic model that self‐consistently traces the growth of supermassive black holes (BH) and their host galaxies within the context of the Lambda cold dark matter (ΛCDM) cosmological framework. In our model, the energy emitted by accreting black holes regulates the growth of the black holes themselves, drives galactic scale winds that can remove cold gas from galaxies, and produces powerful jets that heat the hot gas atmospheres surrounding groups and clusters. We present a comprehensive comparison of our model predictions with observational measurements of key physical properties of low‐redshift galaxies, such as cold gas fractions, stellar metallicities and ages, and specific star formation rates. We find that our new models successfully reproduce the exponential cut‐off in the stellar mass function and the stellar and cold gas mass densities at z∼ 0, and predict that star formation should be largely, but not entirely, quenched in massive galaxies at the present day. We also find that our model of self‐regulated BH growth naturally reproduces the observed relation between BH mass and bulge mass. We explore the global formation history of galaxies and black holes in our models, presenting predictions for the cosmic histories of star formation, stellar mass assembly, cold gas and metals. We find that models assuming the ‘concordance’ΛCDM cosmology overproduce star formation and stellar mass at high redshift (z≳ 2). A model with less small‐scale power predicts less star formation at high redshift, and excellent agreement with the observed stellar mass assembly history, but may have difficulty accounting for the cold gas in quasar absorption systems at high redshift (z∼ 3–4).

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Section: Resultsmentioning

confidence: 99%

A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei

Somerville

Hopkins

Cox

et al. 2008

Monthly Notices of the Royal Astronomical Society

1,141

1,441

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“…The energy output is probably underestimated for adiabatic losses, cavity disruption, undetected cavities, and the omission of shock energy (e.g. Nusser et al 2006;Binney et al 2007). All these factors provide an uncertainty in the jet power of at least a factor of a few.…”

Section: The Jet Kinetic Powermentioning

confidence: 99%

The accretion mechanism in low-power radio galaxies

Balmaverde

Baldi²,

Capetti

2008

A&A

118

154

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We study a sample of 44 low-luminosity radio-loud AGN, which represent a range of nuclear radio-power spanning 5 orders of magnitude, to unveil the accretion mechanism in these galaxies. We estimate the accretion rate of gas associated with their hot coronae by analyzing archival Chandra data, to derive the deprojected density and temperature profiles in a spherical approximation. Measuring the jet power from the nuclear radio-luminosity, we find that the accretion power correlates linearly with the jet power, with an efficiency of conversion from rest mass into jet power of ∼0.012. These results strengthen and extend the validity of the results obtained by Allen and collaborators for 9 radio galaxies, indicating that hot gas accretion is the dominant process in FR I radio galaxies across their full range of radio-luminosity. We find that the different levels of nuclear activity are driven by global differences in the structure of the galactic hot coronae. A linear relation links the jet power with the host X-ray surface brightness. This implies that a substantial change in the jet power must be accompanied by a global change in its ISM properties, driven for example by a major merger. This correlation provides a simple widely applicable method to estimate the jet-power of a given object by observing the intensity of its host X-ray emission. To maintain the mass flow in the jet, the fraction of gas that crosses the Bondi radius reaching the accretion disk must be 0.002. This implies that the radiative efficiency of the disk must be η 0.005, an indication that accretion in these objects occurs not only at a lower rate, but also at lower efficiency than in standard accretion disks.

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“…In particular, pV is likely to be an underestimate of the energy needed to inflate a cavity: the enthalpy of the cavity is for the relativistic plasma in the radio lobes, suggesting that f ∼ 4 may be appropriate. Some authors have even argued for mechanical energies in excess of 10 pV (Nusser, Silk & Babul 2006; Binney, Bibi & Omma 2007) due to additional heating directly from the jets. For f = 4, gives …”

Section: The Mechanical Luminosity Of a Radio Sourcementioning

confidence: 99%

On the jet contribution to the active galactic nuclei cosmic energy budget

Cattaneo

Best

2009

Monthly Notices of the Royal Astronomical Society

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Black holes release energy via the production of photons in their accretion discs but also via the acceleration of jets. We investigate the relative importance of these two paths over cosmic time by determining the mechanical luminosity function (LF) of radio sources and by comparing it to a previous determination of the bolometric LF of active galactic nuclei (AGN) from X‐ray, optical and infrared observations. The mechanical LF of radio sources is computed in two steps: the determination of the mechanical luminosity as a function of the radio luminosity and its convolution with the radio LF of radio sources. Even with the large uncertainty deriving from the former, we can conclude that the contribution of jets is unlikely to be much larger than ∼10 per cent of the AGN energy budget at any cosmic epoch.

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Bubbles as tracers of heat input to cooling flows

Cited by 33 publications

References 27 publications

A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei

A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei

The accretion mechanism in low-power radio galaxies

On the jet contribution to the active galactic nuclei cosmic energy budget

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