Infrared selection is a potentially powerful way to identify heavily obscured AGN missed in even the deepest X-ray surveys. Using a 24 μm-selected sample in GOODS-S, we test the reliability and completeness of three infrared AGN selection methods: (1) IRAC color-color selection, (2) IRAC power-law selection, and (3) IR-excess selection; we also evaluate a number of infrared excess approaches. W...

Aims. We study the hard X-ray luminosity function and absorption distribution of local (z ∼< 0.1) active galactic nuclei (AGN) and discuss the implications for AGN cosmological evolution and for the cosmic X-ray background (CXB). Methods. We use the INTEGRAL all-sky hard X-ray survey to perform a statistical study of a representative sample of nearby AGN. Our entire all-sky sample consists of 1...

Analysis of the frequency and physical properties of galaxies with starformation and AGN activity in different environments in the local universe is a cornerstone for understanding structure formation and galaxy evolution. We have built a new multiwavelength catalog for galaxies in a complete redshift survey (the 15R Survey), gathering information on their Hα, R-band, radio, far-infrared, and X...

We characterize infrared spectral energy distributions of 343 (Ultra) Luminous Infrared Galaxies from z = 0.3− 2.8. We diagnose the presence of an AGN by decomposing individual Spitzer mid-IR spectroscopy into emission from star-formation and an AGN-powered continuum; we classify sources as star-forming galaxies (SFGs), AGN, or composites. Composites comprise 30% of our sample and are prevalent...

We present an intrinsic AGN spectral energy distribution (SED) extending from the optical to the submm, derivedwith a sample of unobscured, optically luminous (νLν,5100 > 1043.5 erg s−1) QSOs at z < 0.18 from the Palomar Green survey. The intrinsic AGN SED was computed by removing the contribution from stars using the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature in the QSOs’ mid-IR spe...

We study the interaction of feedback from active galactic nuclei (AGN) and a multiphase interstellar medium (ISM), in simulations including explicit stellar feedback, multiphase cooling, accretion-disc winds, and Compton heating. We examine radii ∼0.1–100 pc around a black hole (BH), where the accretion rate on to the BH is determined and where AGN-powered winds and radiation couple to the ISM....

Retinoids are important regulators of epithelial differentiation. AGN 193109 is a high-affinity antagonist and inverse agonist for the nuclear retinoic acid receptors (RARs). Paradoxically, both AGN 193109 and retinoid agonists inhibit the expression of the differentiation marker MRP-8 in normal human keratinocytes (NHKs). TTNPB, an RAR agonist, and AGN 193109 mutually antagonize MRP-8 inhibiti...

We are searching for large-scale structures in the distribution of AGN discovered by the ROSAT AllSky Survey. The RASS detected > 60000 X-ray objects, of which ≈ 35% are AGN at z < 0.5. The surface density in the extragalactic sky is ≈ 0.5 AGN/deg, which has not been reached until now by any other survey for this redshift range. We efficiently single out the AGN among all the RASS sources using...

We have analyzed the clustering of ∼ 90, 000 narrow-line AGN drawn from the Data Release 4 (DR4) of the Sloan Digital Sky Survey. Our analysis addresses the following questions: a) How do the locations of galaxies within the large-scale distribution of dark matter influence ongoing accretion onto their central black holes? b) Is AGN activity triggered by interactions or mergers between galaxies...

We use HST/ACS images and a photometric catalog of the COSMOS field to analyze morphologies of the host galaxies of ∼400 AGN candidates at redshifts 0.3 < z < 1.0. We compare the AGN hosts with a sample of non-active galaxies drawn from the COSMOS field to match the magnitude and redshift distribution of the AGN hosts. We perform 2-D surface brightness modeling with GALFIT to yield host galaxy ...