Black hole “feedback” is the positive or negative effect of the radiation and kinetic energy dumped by an accreting black hole, an Active Galactic Nucleus or AGN, on the galaxy hosting it.  The radiation and outflows couple to the gas influencing its (thermo)dynamics.

Seth_SuperEdd
Snapshot from a cosmological simulation showing the bipolar outflow, in red, from a black hole in a high-redshift galaxy, embedded within the cosmic web of filaments and other primordial galaxies. Credits: Yohan Dubois, the Seth simulation.

 

AGN feedback is often invoked as a way to regulate star formation and eventually galaxy growth. It must also be realized how AGN feedback regulates black hole growth. The energy and momentum released from the black hole itself affects how gas flows.

We study AGN feedback to understand how black holes grow in galaxies.

Screen Shot 2016-01-06 at 15.42.24
Meridional section of gas density (left), temperature (middle) and radial velocity (right) for a simulation resolving the Bondi radius of a black hole, while at the same time extending to the full galaxy size. Here, we witness the beginning of an accretion episode. Infalling gas is feeding the black hole, while the wind created by the black hole activity begins to inject mass, energy and momentum in the gas surrounding the black hole.

 

Screen Shot 2016-01-06 at 15.42.34
After about one million years, the AGN-driven wind has created a central hot bubble, temporarily shutting down the feeding of the black hole, which becomes quiescent. Negri et al., in prep.

Some black holes produce relativistic, collimated jets that pierce into the galaxy and “stir” the gas around them.

backflowLong_1E43-15 (dragged)
The complex interaction between a collimated jet and the gas on its path. Cielo et al., in prep.