English

Unifying the micro and macro properties of AGN feeding and feedback

High Energy Astrophysical Phenomena 2017-03-22 v2 Astrophysics of Galaxies Computational Physics Fluid Dynamics

Abstract

We unify the feeding and feedback of supermassive black holes with the global properties of galaxies, groups, and clusters, by linking for the first time the physical mechanical efficiency at the horizon and Mpc scale. The macro hot halo is tightly constrained by the absence of overheating and overcooling as probed by X-ray data and hydrodynamic simulations (εBH\varepsilon_{\rm BH} \simeq 103Tx,7.4^{-3}\, T_{\rm x,7.4}). The micro flow is shaped by general relativistic effects tracked by state-of-the-art GR-RMHD simulations (ε\varepsilon_\bullet \simeq 0.03). The SMBH properties are tied to the X-ray halo temperature TxT_{\rm x}, or related cosmic scaling relation (as LxL_{\rm x}). The model is minimally based on first principles, as conservation of energy and mass recycling. The inflow occurs via chaotic cold accretion (CCA), the rain of cold clouds condensing out of the quenched cooling flow and recurrently funneled via inelastic collisions. Within 100s gravitational radii, the accretion energy is transformed into ultrafast 104^4 km s1^{-1} outflows (UFOs) ejecting most of the inflowing mass. At larger radii the energy-driven outflow entrains progressively more mass: at roughly kpc scale, the velocities of the hot/warm/cold outflows are a few 103^3, 1000, 500 km s1^{-1}, with median mass rates ~10, 100, several 100 M_\odot yr1^{-1}, respectively. The unified CCA model is consistent with the observations of nuclear UFOs, and ionized, neutral, and molecular macro outflows. We provide step-by-step implementation for subgrid simulations, (semi)analytic works, or observational interpretations which require self-regulated AGN feedback at coarse scales, avoiding the a-posteriori fine-tuning of efficiencies.

Keywords

Cite

@article{arxiv.1701.07030,
  title  = {Unifying the micro and macro properties of AGN feeding and feedback},
  author = {M. Gaspari and A. Sadowski},
  journal= {arXiv preprint arXiv:1701.07030},
  year   = {2017}
}

Comments

11 pages, 2 figures; accepted in ApJ (added further insights) -- Reviewer: "The paper is very well written and the results will be very important to help the advancement of both theoretical and observational studies in the field of AGN feedback and galaxy evolution."