AGN feedback is often invoked in galaxy evolution, as a key physical mechanism to self-regulate star formation and black hole accretion. Is this mechanism truly effective? How to tell? I will describe a series of new experiments designed to use the ISM properties of quasar host galaxies to test the efficiency of AGN feedback. I will also introduce new methods to estimate the star formation...
In this talk I will review the phenomenology of accreting supermassive black holes and their jets. The understanding that has emerged from their systematics at multiple frequencies, combined with the results from computational simulations and connections with properties of their host galaxies and their evolution will be discussed.
Half of all clusters of galaxies have a cool core in which the temperature drops inward and the density rises as expected from a cooling flow. Over 20 years ago, High Resolution XMM RGS Spectra showed little evidence for the cooling flow continuing below 1 keV at the rates inferred from higher temperatures. We have now re-examined the RGS spectra of over 20 clusters and groups and 4 early-type...
Nearly every massive galaxy contains a supermassive black hole (BH) in their centers. For decades, both theories and numerical simulations suggest a central role of BHs in regulating the growth of galaxies. In particular, BH feedback through heating or blowing up the interstellar medium (ISM) serves as the foundation for current models of massive galaxy formation. However, direct evidence for...
Observations suggest that feedback from Active Galactic Nuclei (AGN) plays important role in the evolution of large scale structures of the universe. However, the exact physics of coupling the feedback energy to their surrounding medium is still not well understood. In this talk I will try to explain our work to investigate different modes of AGN feedback and their effects on the surrounding...
The early evolution of the black hole mass function (BHMF) and quasar luminosity function (QLF) encodes key information on the physics determining the radiative and accretion processes of black holes (BHs) growing in high-redshift galaxies. Starting from the formation of seed BHs as their parent halos evolve, we study primordial gas collapse in the biased quasar host halos, computing gas...
Supercritical growth of massive/stellar mass seed BHs at high-z universe is believed to be one of the possible solutions to grow the observed supermassive black holes (SMBHs) at z~6. We study the long-term evolution of the global structure of axisymmetric accretion flows onto a black hole (BH) at rates substantially higher than the Eddington value, performing two-dimensional radiation...
The shape of the ambient circumnuclear medium (ACM) density profile can probe the history of accretion onto the central supermassive black holes in galaxies and circumnuclear environment. However, due to the limitations of instrument resolution, the density profile of the ACM for most galaxies remain largely unknown. Here we propose a novel method to measure the ACM density profile of active...
