We present preliminary results from the largest-ever survey of high-resolution associated absorption line (AAL) region metallicities and physical properties in a sample of high redshift (z > 3) quasars.

Feedback from AGN is a key component in most current models of galaxy formation and evolution. For the most massive galaxies, heating and removal of gas by the AGN could precipitate an abrupt quenching of star formation during a dramatic blow-out phase. The “smoking gun” for such a scenario would be direct evidence of powerful outflows associated with the jet. I present some preliminary results of a program to look for these in high-z radio galaxies (HzRGs). Recent observations of the z = 1.5 radio galaxy 3C 230 obtained with the NIFS integral-field spectrograph and Altair laser adaptive optics facility on Gemini North are shown. These reveal with unprecedented resolution the complex kinematics of this system in redshifted Hα and [N ii] emission. The bi-polar velocity field is aligned with the jet axis, with a kinematic center associated with the radio core itself, and turbulent edges approaching the galaxy's escape velocity. This suggests a gas mass of roughly 1011M⊙ has been propagating outwards for 107 to 108 years, corresponding to a mass loss of roughly 102–3M⊙ yr−1, based on its velocity and spatial extent. This is in good agreement with the energetics and typical ages of radio jets, and likely heralds the onset of the “red and dead” stage for this HzRG.

Recent detailed studies of narrow absorption line (NAL) systems in QSO spectra have revealed that at least 50% of QSOs have NALs associated with the central engine, and in most cases they are found to be outflowing. Will studies of NALs provide the much sought-after evidence for ubiquitous QSO feedback that can halt the formation of stars in galaxies? I present new results on the distribution of line-of-sight velocity offsets between Mg ii absorbers and their background QSOs, based on a large catalogue of absorbers from SDSS DR6 and greatly improved QSO redshift estimates. The analysis reveals high velocity Mg ii NALs out to at least 6000 km s−1 from the QSO, which cannot be ascribed to the clustering of local galaxies, similar to that observed for C iv absorbers. The existence of such low-ionization, high-velocity gas clouds in the intense ionixing field of the QSO suggests that we may indeed be witnessing the mechanical expulsion of gas, alongside the heating previously observed. We also find an excess of low-velocity Mg ii NALs in radio-loud QSOs compared to radio-quiet QSOs, consistent with their different clustering amplitudes.

I describe ways in which state-of-the-art cosmological simulations are modeling the growth and evolution of supermassive black holes (feeding), and the impact of the energy that they release on galaxies and their surroundings (feedback). I then discuss how this new picture of interconnected co-evolution of galaxies and black holes provides plausible explanations for several of the mysteries that have long vexed theorists studying galaxy formation within the hierarchical cold dark matter paradigm.

Recent observations of tight correlations between supermassive black hole masses and the properties of their host galaxies demonstrate that black holes and bulges are co-eval and have motivated theoretical models in which feedback from AGN activity regulates the black hole and host galaxy evolution. Combining simulations, analytic models, and recent observations, answers to a number of questions are starting to take shape: how do AGN get triggered? How long do they live? What are typical light curves and what sets them? Is feedback necessary and/or sufficient to regulate BH growth? What effects does that feedback have on the host galaxy? On the host halo? All of this also highlights questions that remain wide open: how does gas get from a few pc to the AGN? What are the actual microphysical mechanisms of feedback? What is the tradeoff between stellar and AGN feedback? And, if there are different “modes” of feedback, where/when are each important?

The study of the conditions and the kinematics of the gas in the central region of AGN provides important information on the relevance of feedback effects connected to the nuclear activity. Quantifying these effects is key for constraining galaxy evolution models. Here we present a short summary of our recent efforts to study the occurrence and the impact of gas outflows in radio-loud AGN that are in their first phase of their evolution. Clear evidence for AGN-induced outflows has been found for the majority of these young radio sources. The outflows are detected both in (warm) ionized as well in (cold) atomic neutral gas, and they are likely to be driven (at least in most of the cases) by the interaction between the expanding jet and the medium. The mass outflow rates of the cold gas (Hi) appear to be systematically higher than those of the ionized gas. The former reach up to ~50 M⊙ yr−1 and are in the same range as “mild” starburst-driven superwinds in ULIRGs, whilst the latter are currently estimated to be a few solar masses per year. However, the kinetic powers associated with these gaseous outflows are a relatively small fraction (a few × 10−4) of the Eddington luminosity of the galaxy. Thus, they do not appear to match the requirements of the galaxy evolution feedback models.

We use data from large surveys of the local universe (SDSS+Galaxy Zoo) to show that the galaxy–black hole connection is linked to host morphology at a fundamental level. The fraction of early-type galaxies with actively growing black holes, and therefore the AGN duty cycle, declines significantly with increasing black hole mass. Late-type galaxies exhibit the opposite trend: the fraction of actively growing black holes increases with black hole mass.

The absence of vigorous star formation in early-type galaxies is a mystery because early-type galaxies do have a copious supply of cold gas. Various heating mechanisms have been put forward to explain this, and AGN feedback is one of the most widely suspected culprits. The GALEX UV telescope detects even a small amount of star formation and allows an estimate of the current and recent star formation. We find that star formation is still common in early-type galaxies with low velocity dispersion where the black hole mass is believed to be small. We compare the star-formation rates of the galaxies with predictions from various semi-analytic models with different feedback prescriptions. We find that the passive behavior of central galaxies in groups and clusters is reproduced by semi-analytic models with AGN feedback. However, the same prescriptions causes satellite (i.e., non-central) galaxies to be quenched as well, much more than observed by GALEX, leading to a “satellite over-quenching problem.”

We discuss a numerical model for black hole (BH) growth and feedback that allows simultaneous tracking of the evolution of galaxies and their central BHs in fully cosmological simulations. After describing the main features of the numerical model adopted, we show how BHs in these simulations affect the properties of their host halos and how this in turn impacts the growth of the BHs themselves. We also present results from a set of simulations specifically designed to address the issue of BH assembly in the early Universe and discuss whether or not different extensions of the model, in particular rapidly spinning BHs and gravitational recoils, can hamper the formation of the first bright quasars.

Recent numerical relativity simulations predict that coalescing supermassive black holes (SMBHs) can receive kick velocities up to several thousands of kilometers per second due to anisotropic emission of gravitational waves, leading to long-lived oscillations of the SMBHs in galaxy cores and even SMBH ejections from their host galaxies. Observationally, accreting recoiling SMBHs would appear as quasars spatially and/or kinematically offset from their host galaxies. The presence of these “kicks” and “superkicks” has a wide range of exciting astrophysical implications which only now are beginning to be explored, including consequences for black hole and galaxy growth at the epoch of structure formation, modes of feedback, unified models of AGN, and the number of obscured AGN. SMBH recoil oscillations beyond the torus scale can be on the order of a quasar lifetime, thus potentially affecting a large fraction of the quasar population. We discuss how this might explain the long-standing puzzle of a deficiency of obscured type 2 quasars at high luminosities. Observational signatures of recoiling SMBHs are discussed and results from follow-up studies of the candidate recoiling SMBH SDSSJ0927+2943 are presented.

The interplay between active galactic nuclei (AGNs) and their host galaxies' star-formation activities is one of the central topics in pursuing an understanding of galaxy evolution. With the advent of the Galaxy Evolution Explorer (GALEX), we have much more accurate information than ever about the recent star formation (RSF) histories of early-type galaxies within ~ 1.5 Gyr in the local universe. Using a subset of ~ 1000 GALEX/SDSS type 2 AGN-host early-type galaxies (E/S0) based on the emission-line ratio diagnosis, we explore how AGNs affect the RSF histories of the early-type hosts and vice versa. In this contribution, we present a preliminary yet interesting result on the intimate connection between AGN activity and the RSF histories of early-type galaxies.

Within the hierarchical CDM framework, gas-poor mergers contribute substantially to the building of the most massive galaxies (Faber et al. 2007). We want to test this scenario by studying the fundamental plane (FP) and the stellar populations of the most massive galaxies. We investigate a well-defined sample of massive early-type galaxies at 0.1<z<0.4, identified from the SDSS database. Out of 42,000 possible targets in the SDSS database, we extracted 23 luminous early-type galaxies with bona fide high velocity dispersions of σ>350 km s−1. These systems are located either in high or low-density environments and show a variety of small surface-brightness structure. Using archival HST/ACS images and Gemini/GMOS spectroscopy, we will explore the photometric and spectroscopic properties of these galaxies.

We investigate the origin of the color-magnitude relation (CMR) observed in cluster galaxies by using a combination of a cosmological N-body simulation of a cluster of galaxies and a semi-analytic model of galaxy formation. The departure of galaxies in the bright end of the CMR with respect to the trend defined by less luminous galaxies could be explained by the influence of minor mergers.

We present binary galaxy merger simulations of gas-rich disks (Sp-Sp), of early-type galaxies and disks (E-Sp, mixed mergers), and mergers of early-type galaxies (E-E, dry mergers) including radiative cooling, star formation, black hole (BH) accretion, and the associated feedback processes. The numerical simulations include cooling, star formation, supernova feedback, and BH accretion modeled following a Bondi–Hoyle accretion parameterization. The maximum accretion rate is limited to the Eddington rate, with a total of 0.5% of the accreted rest-mass energy distributed as thermal energy to the surrounding gas.

Using an AGN sample from the INTEGRAL all-sky survey, we show that the density fluctuations of matter in the local universe translate linearly into the density fluctuations of accreting supermassive black holes. Our results imply that hard X-ray emitting AGNs are unbiased tracers of the galaxy population in the nearby universe and SMBH activity is independent of the density of galaxies.

Far ultraviolet (FUV) emission is observed in the central regions of cool-core clusters with the Hubble Space Telescope (HST). It is traced out to 20 kpc from the nuclei of the brightest cluster galaxies and found to be distributed in clumps and filaments, as shown in Figure 1. The FUV emission matches the global structure of the ionized gas nebulae. If produced by stars, this emission can account for the ionization but not the temperature of the gas (Voit & Donahue 1997; Oonk et al. in preparation).

We present a new catalog of isolated galaxies (coined as UNAM–KIAS) obtained through an automated systematic search. The 1520 isolated galaxies were found in ~ 1.4 steradians of the sky in the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) photometry. The selection algorithm was implemented from a variation of the criteria developed by Karachentseva (1973), with full redshift information. This new catalog is aimed to carry out comparative studies of environmental effects and constraining the currently competing scenarios of galaxy formation and evolution.