We investigate the infrared contribution from supermassive black hole activity versus host galaxy emission in the mid to far-infrared (IR) spectrum for a large sample of X-ray bright active galactic nuclei (AGN) residing in dusty, star-forming host galaxies. We select 703 AGN with L X = 10 42 − 10 46 ergs s −1 at 0.1 < z < 5 from the Chandra XBoötes X-ray Survey with rich multi-band observations in the optical to far-IR. This is the largest sample to date of X-ray AGN with mid and far-IR detections that uses spectral energy distribution (SED) decomposition to determine intrinsic AGN and host galaxy infrared luminosities. We determine weak or nonexistent relationships when averaging starformation activity as a function of AGN activity, but see stronger positive trends when averaging L X in bins of star-forming activity for AGN at low redshifts. We estimate an average dust covering factor of 33% based on infrared SEDs and bolometric AGN luminosity, corresponding to a Type 2 AGN population of roughly a third. We also see a population of AGN that challenge the inclination based unification model with individual dust covering factors that contradict the nuclear obscuration expected from observed X-ray hardness ratios. We see no strong connection between AGN fractions in the IR and corresponding total infrared, 24 µm, or X-ray luminosities. The average rest-frame AGN contribution as a function of IR wavelength shows significant (∼ 80%) contributions in the mid-IR that trail off at λ > 30 µm. Additionally, we provide a relation between observed L X and pure AGN IR output for high-z AGN allowing future studies to estimate AGN infrared contribution using only observed X-ray flux density estimates.

The largest Herschel extragalactic surveys, H-ATLAS and HerMES, have selected a sample of "ultrared" dusty, star-forming galaxies (DSFGs) with rising SPIRE flux densities (S 500 > S 350 > S 250 ; so-called "500 µm-risers") as an efficient way for identifying DSFGs at higher redshift (z > 4). In this paper, we present a large Spitzer follow-up program of 300 Herschel ultrared DSFGs. We have obtained high-resolution ALMA, NOEMA, and SMA data for 63 of them, which allow us to securely identify the Spitzer/IRAC counterparts and classify them as gravitationally lensed or unlensed. Within the 63 ultrared sources with high-resolution data, ∼65% appear to be unlensed, and ∼27% are resolved into multiple components. We focus on analyzing the unlensed sample by directly performing multi-wavelength spectral energy distribution (SED) modeling to derive their physical properties and compare with the more numerous z ∼ 2 DSFG population. The ultrared sample has a median redshift of 3.3, stellar mass of 3.7 × 10 11 M , star formation rate (SFR) of 730 M yr −1 , total dust luminosity of 9.0 × 10 12 L , dust mass of 2.8 × 10 9 M , and V-band extinction of 4.0, which are all higher than those of the ALESS DSFGs. Based on the space density, SFR density, and stellar mass density estimates, we conclude that our ultrared sample cannot account for the majority of the star-forming progenitors of the massive, quiescent galaxies found in infrared surveys. Our sample contains the rarer, intrinsically most dusty, luminous and massive galaxies in the early universe that will help us understand the physical drivers of extreme star formation.

Affinity capillary electrophoresis (ACE) is a versatile analytical technique that has been shown to be an efficient and accurate tool to probe non-covalent interactions and to determine binding and dissociation constants between receptors and ligands. ACE uses as its basis the change in migration time of a receptor upon binding to a ligand generally found in the electrophoresis buffer. Subsequent analysis using non-interacting standards realizes values for the binding constant. The technique has a number of advantages over other binding assay methods in that binding parameters can be obtained expeditiously, reproducibly, and with minimal sample quantity requirements and preparation. This review focuses on the literature describing the use of ACE from

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