Outflows in the gaseous disks of active galaxies and their impact on black hole scaling relations

Abstract

To solve the still unsolved and fundamental problem of the role of active galactic nucleus (AGN) feedback in the shaping of galaxies, we implement eda new physical treatment of AGN-driven winds into our semi-analytic model of galaxy formation. With each galaxy in our model, we associated solutions for the outflow expansion and the mass outflow rates in different directions, depending on the AGN luminosity, on the circular velocity of the host halo and on the gas content of the considered galaxy. We also assigned an effective radius to each galaxy that we derived from energy conservation during merger events, and a stellar velocity dispersion that we self-consistently computed via Jeans modeling. We derived all the main scaling relations between the black hole (BH) mass and the stellar mass of the host galaxy and of the bulge, the velocity dispersion, the host halo dark matter mass, and the star formation efficiency. We find that our improved AGN feedback mostly controls the dispersion around the relations, but it plays a subdominant role in shaping slopes and/or normalizations of the scaling relations. The models agree better with the available data when possible limited-resolution selection biases are included. The model does not indicate that any more fundamental galactic property is linked to BH mass. The velocity dispersion plays a similar role as stellar mass, which disagrees with current data. In line with other independent studies carried out on comprehensive semi-analytic and hydrodynamic galaxy-BH evolution models, our current results signal either that the current cosmological models of galaxy formation are inadequate in their reproduction of the local scaling relations in terms of both shape and residuals, and/or they indicate that the local sample of dynamically measured BHs is only incompletely known.

Dynamical complexity in microscale disk-wind systems

“…The third broad scenario includes cosmological simulations using both semi-analytic models (SAM; Fontanot et al 2020;Menci et al 2014Menci et al , 2023 and references therein) and hydrodynamic numerical models (e.g., Di Matteo et al 2005;Costa et al 2014;Sijiacki et al 2015). These simulations follow the growth of density perturbations of the dark matter field and incorporate baryon physics at some level of detail to describe star formation, galaxy and BH growth, and stellar and BH feedback processes.…”

Revisiting the Surface Brightness Profile of the Stellar Disk with the Statistical Mechanics of the Self-Gravitating System with the Central Body

“…Note that β is determined by the energy constraint. Analyzing Equation (15), we find that in the central region, if the black hole mass is large (but not excessively so), terms involving b and f (r) can be ignored, while the µ-related term remains significant. This leads to a solution for (15):…”

“…However, there are exceptions characterized by a very steep central slope, necessitating the consideration of cases where b ̸ = 0. In such scenarios, M • is significantly larger, complicating the analytical solution of Equation (15). The numerical solution suggests a surface density profile in the central region described by:…”

“…where γ is determined by the total angular momentum, l = ω 2 R 2 * ρ * /P * , and other quantities are as defined in Equation (15). Irrespective of whether r is large or small, the term involving l tends to zero, thus having weak impact on the SBPs of the stellar disk, but from Figure 5 we can still find that the stellar disks with the same surface density but smaller spin have a slightly smaller radius, and l = 0 is just the above case with no angular momentum.…”

“…This is exemplified by the M • − M b relationship, as discussed in [8][9][10], and the M • − σ relationship proposed by [11], where M • and M b represent the masses of the black hole and bulge, respectively, and σ is the velocity dispersion of the stars in the bulge. Although many authors, such as [12][13][14][15], suggest that these correlations may stem from black hole accretion and feedback mechanisms, the underlying physical connections among the black hole, bulge, and disk are yet to be comprehensively understood.…”