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Abstract: The deposition of mechanical feedback from a supermassive black hole SMBHin an active galactic nucleus AGN into the surrounding galaxy occurs viabroad-line winds which must carry mass and radial momentum as well as energy.The effect can be summarized by the dimensionless parameter$\eta=dot{M outflow}-dot{M accretion}= 2 \epsilon w c^2-v w^2$ where$\epslion w \equiv dot{E} w-dot{M accretion} c^2$ is the efficiency bywhich accreted matter is turned into wind energy in the disc surrounding thecentral SMBH. The outflowing mass and omentum are proportional to $\eta$, andmany prior treatments have essentially assumed that $\eta=0$. We perform one-and two-dimensional simulations and find that the growth of the central SMBH isvery sensitive to the inclusion of the mass and momentum driving but isinsensitive to the assumed mechanical efficiency. For example in representativecalculations, the omission of momentum and mass feedback leads to an hundredfold increase in the mass of the SMBH to over $10^{10} \Msun$. When allowanceis made for momentum driving, the final SMBH mass is much lower and the windefficiencies which lead to the most observationally acceptable results arerelatively low with $\epsilon w \lesssim 10^{-4}$.



Author: Jeremiah P. Ostriker, Ena Choi, Luca Ciotti, Gregory S. Novak, Daniel Proga

Source: https://arxiv.org/







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