The AKARI NEP Deep Field Survey is an international multiwavelength survey over 0.4 deg2 of the sky. This is the deepest survey made by the InfraRed Camera (IRC) of the infrared astronomical satellite AKARI with 9 filters continuously covering the 2-25 μm range. This has been supplemented by other ground-based and space multiwavelength data ranging from X-ray (Chandra), UV (GALEX), Optical-NIR (Subaru Sprime-cam, CFHT/WIRCAM, CFHT/Megacam, KPNO Flamningos among others for imagings as well as Keck Diemos, Subaru Focas, Subaru FMOS, WIYN Hydra, and GTC OSIRIS for spectra), far-infrared (Herschel) and radio (WSRT and e-Merlin). The uniqueness of the field lies in the availability of four filters between 9-18 μm, which fall into the Spitzer gap between the IRAC and MIPS instruments. This made this field one of the deepest at ~ 15 μm and the deepest among those with similar solid angles. This enabled us to make sensitive MIR detection of AGN candidates around z ~ 1. The MIR selection is based on hot dust emission in the AGN torus and is efficient in detecting highly obscured Compton-thick AGN population. A number of team members have worked (e.g. Hanami et al. 2012) or are working on a catalog of AGN candidates in this field. In this presentation, we report the results of the Chandra observations on this field. The field was covered by 15 overlapping Chandra ACIS-I observations (including our own and from archive) with a total exposure of 310 ks, detecting ~ 500 X-ray sources. We explain our improved source detection procedure for highly overlapped Chandra images and results. We utilize the stacking analysis (both in the observed and rest-frame) of the MIR AGN candidates that are not detected individually. The stacking analysis is expected to detect the summed X-ray flux from scattered components and Fe-lines. The results are discussed in terms of quantifying the Compton-thick populations at z ~ 1.

We use the WISE all sky survey observations to look for counterparts of hard X-ray selected sources from the XMM-Newton-SDSS survey. We then measure the 12 μm luminosity of the AGN by decomposing their optical to infrared SEDs with a host and an AGN component and compare it to the X-ray luminosity and their expected intrinsic relation. This way we select 20 X-ray under-luminous heavily obscured candidates and examine their X-ray and optical properties in more detail. We find evidence for a Compton-thick nucleus for six sources, a number lower than what expected from X-ray background synthesis models, which shows the limitations of our method.

New estimates of the interband lags between variations in the B band and variations in the V, R, and I bands for three active galactic nuclei (AGNs) are present. In contrast to the previous study by Sergeev et al. (2005), the effect of the contribution of the broad lines to the bands is taken into account.

We present results of 4 years of VLBA monitoring along with γ-ray and optical R-band photometric observations of 6 blazars (0420-014, 1156+295, 1222+216, PKS 1510-089, 1633+382 and CTA 102). We have analyzed total intensity images obtained with the VLBA at 43 GHz and investigated kinematic evolution of the pc-scale jets of the sources. For all sources we compare flux variations in the VLBI core and bright superluminal knots with γ-ray and optical light curves. The majority of γ-ray flares are coincident with the appearance of a new superluminal knot and/or a flare in the millimeter-wave core and at optical wavelengths. These results support the conclusion that for many flares in blazars the region of the enhanced γ-ray and optical emission is located in the vicinity or downstream of the mm-wave VLBI core.

Integral field spectroscopy provides us with immensely rich datasets about spatially resolved distributions and kinematics of emission and absorption lines. In this contribution I will describe some of the key insights that have been made about AGN using optical, near infrared, and far infrared IFUs. These encompass gas inflow and outflow mechanisms, and the relations between star formation, the torus, and accretion onto the black hole. Progress so far has largely relied on archetypal and small sets of objects. In the future, a more statistically robust approach will be required. I will end by discussing a number of issues that can easily confuse an emerging picture, and need to be borne in mind for such surveys.

The current galaxy formation paradigm postulates that a significant amount of gas accretes onto galaxies from the IGM in a cold T ~ 104K phase, and many have argued that this gas should be detectable in diffuse Lyα emission. However, so far, there are no convincing direct detections.

We are conducting a deep (down to 1σ ~ 5 − 10 × 10−19 erg s−1 cm−2 arcsec−2) and the first statistical survey matching the Lyα line around radio-quiet quasars at z ~ 2. By taking advantage of the boost in fluorescent Lyα emission due to the ionizing radiation emitted by a luminous QSO that, like a flashlight, can illuminate the hydrogen in its vicinity, we will be able to constrain some of the properties of the gas sorrounding z ~ 2 QSOs. In particular, with this unique dataset, we can conduct the first deep statistical census of the size, morphology, luminosity, frequency, and covering factor of Lyα emission around QSOs.

The empirical relations in the black hole-accretion disk-relativistic jet system and physical processes behind these relations are still poorly understood, partly because they operate close to the black hole within the central light year. Very long baseline array (VLBA) provides unparalleled resolution at 15 GHz with which to observe the jet components at sub-milliarcsecond scales, corresponding to sub-pc-scales for local blazars. We discuss the jet inner structure of blazars, location and radiation mechanisms operating in the innermost parsec-scale region of blazars, and evidence for jet-excited broad-line region (BLR) ouflowing downstream the jet. Outflowing BLR can provide necessary conditions for production of high energy emission along the jet between the base of the jet and the BLR and far beyond the BLR as evidenced by recent observations. Flat spectrum quasars and low synchrotron peaked sources are the most likely objects to host the outfllowing BLR. From the γ-ray absorption arguments, we propose that the jet-excited region of the outflowing BLR in quasars is small and/or gas filling factor is low, and that the orientation and opening angle of the outflowing BLR can lead to relevant γ-ray absorption features observed in quasars.

The physics of active black holes (BHs) is governed by three key parameters: their mass, spin, and accretion rate. Understanding the cosmic evolution of these parameters is crucial for tracing back the growth of the BHs to the epoch of their formation. We have selected a unique AGN sample, in a narrow redshift range around z = 1.55, based on both BH mass and Eddingtion ratio, and we observed them with the X-Shooter instrument on the VLT, covering the rest wavelength range ~1200 to 9800 Å. This wide wavelength range allows us to study, simultaneously, more emission lines (i.e., CIV 1550 Å through H-alpha), and a larger portion of the global AGN SED, than any previous studies. We currently have a sample of 30 quasars already observed and spanning BH masses from ~108 to 109 Msolar and Eddington ratio from ~0.03 to 0.7. We focus here on our first science goal, comparing the observed AGN SED to thin accretion disk models in order to identify the origin of the SED. We also discuss the unique capability of this sample to identify any emission-line profile dependencies on BH mass and the Eddington ratio, and to compare mass determination methods based on four different emission-line profiles (Hα, Hβ, MgII 2800 Å, and CIV 1550 Å).

We systematically search for discrete absorption events in the vast archive of the Rossi X-ray Timing Explorer. This includes dozens of nearby type I and Compton-thin type II AGN and covers timescales from days to over a decade for individual objects. We are sensitive to discrete absorption events due to clouds of full-covering, neutral or mildly-ionized gas with columns 1022−25 cm−2 transiting the line of sight. We detect 13 eclipse events in 8 objects, roughly tripling the number of previously published events from this archive. Despite sensitivity to events with NH up to 1024−25 cm−2, we measured no Compton-thick eclipses in our sample. Peak column densities span 2.5–19 × 1022 cm−2. Event durations span hours to months. We infer the clouds distances from the black hole, assuming Keplerian motion, to span 0.2–80 × 104 Schwarzschild radii. We find no statistically significant difference between the individual cloud properties of type I and II objects. The presence of eclipses in both type Is and IIs argues against sharp-edged cloud distributions. The type II AGN show a level of “base-line” X-ray absorption that is consistent with being constant over timescales from 0.6 to 8.4 yr. This can either be explained by a homogeneous medium, or by X-ray-absorbing clouds that each have NH ≪ 1022 cm−2. Considering the “selection function” of the monitoring, we derive the probability of cloud occultation events. Finally, we derive the first X-ray statistical constraints for clumpy-torus models.

Radiatively inefficient, hot accretion flows are widely considered as a relevant accretion mode in low-luminosity AGNs. We study spectral formation in such flows using a refined model with a fully general relativistic description of both the radiative (leptonic and hadronic) and hydrodynamic processes, as well as with an exact treatment of global Comptonization. We find that the X-ray spectral index–Eddington ratio anticorrelation as well as the cut-off energy measured in the best-studied objects favor accretion flows with rather strong magnetic field and with a weak direct heating of electrons. Furthermore, they require a much stronger source of seed photons than considered in previous studies. The nonthermal synchrotron radiation of relativistic electrons seems to be the most likely process capable of providing a sufficient flux of seed photons. Hadronic processes, which should occur due to basic properties of hot flows, provide an attractive explanation for the origin of such electrons.

The Seyfert galaxy MCG–6-30-15 has recently been observed in the infrared using SINFONI on the VLT, reaching a very high spatial resolution of 0.1 arcsec. This allowed us for the first time to detect a stellar kinematically decoupled core in the inner r < 125 pc of the galaxy. Here we summarise the main theories for the formation of the decoupled core and the implications on the study of this galaxy.

The intriguing existence of ‘True’-Seyfert 2s has opened a debate on the validity of the unified model of active galactic nuclei (AGN). These objects, also called ‘Naked’-AGN, seem to lack a broad line region. In some cases, their X-ray emission is unabsorbed, typical of Seyfert 1 galaxies, indicating a clear view toward the nucleus, but no broad lines are seen in the optical. In ‘True’-Seyfert 2s with higher column densities, observations of polarized light have failed to reveal the hidden broad emission. We performed high-resolution near-infrared integral-field observations of two ‘True’-Seyfert 2 candidates: IRAS 01072+4954 and NGC 7496. We found that the AGN in these sources might power very faint and narrow broad emission lines (FWHMbroad < 1500km s−1). Here, we discuss the properties of the broad components estimated from published X-ray and/or optical measurements and present their near-infrared candidate identification. Both galaxies host intermediate-mass black holes, with masses ~ 105−106 M⊙. Our results favor the unified model in the cases of high accretion rates, and stress the necessity of a multiwavelength approach to unveil the nature of ‘Naked’-AGN.

To test recent suggestions that the infrared emission of low-luminosity AGN arises in a truncated thin accretion disk, we compare recent, high-resolution IR data with published SED model fits that include emission from the truncated disk. We also fit the data with clumpy torus and optically thin dust shell models. These comparisons suggest that dust can better account for the IR emission of the objects in question than can the truncated disk. That optically thin models give a good fit to the data may support a scenario in which the torus of the AGN unified model does not persist in low accretion rate AGN.

Galaxies, which often contain ionised gas, sometimes also exhibit a so-called low-ionisation nuclear emission line region (LINER). For 30 years, this was attributed to a central mass-accreting supermassive black hole (more commonly known as active galactic nucleus or AGN) of low luminosity, making LINER galaxies the largest AGN sub-population, which dominate in numbers over higher AGN-luminosity Seyfert galaxies and quasars. This, however, poses a serious problem. While the inferred energy balance is plausible, many LINERs clearly do not contain any other independent signatures of an AGN. Using integral field spectroscopic data from the CALIFA survey, we compare the observed radial surface brightness profiles with what is expected from illumination by an AGN. For 48 galaxies with LINER-like emission we show, that the radial emission-line surface brightness profiles are inconsistent with ionisation by a central point-source and hence cannot be due to an AGN alone. The most probable explanation for the excess LINER-like emission is ionisation by evolved stars during the short but very hot and energetic phase known as post-AGB. This leads us to an entirely new interpretation. Post-AGB stars are ubiquitous and their ionising effect should be potentially observable in every galaxy with gas present and with stars older than ~1 Gyr, unless a stronger radiation field from young hot stars or an AGN outshines them. This means, that galaxies with LINER-like emission are not a class defined by a property but rather by the absence of a property. It also explains why LINER emission is observed mostly in massive galaxies with old stars and little star formation.

Using 192 composite spectra stacked from subsamples of individual SDSS quasar spectra binned in spectral index, αλ, and logarithm of monochromatic luminosity at 1450 Å, log l1450, and modelling separate spectral ranges with superposition of emission lines it was found that: there is a dependence of emission line equivalent width (EW) on αλ (correlation or anti-correlation) for some lines, mostly for those lines for which the Baldwin effect is detected, while for the lines for which the Baldwin effect is not observed any αλ-dependence was found.

In these proceedings I briefly: (1) review the impact (or “feedback”) that active galactic nuclei (AGN) are predicted to have on their host galaxies and larger scale environment, (2) review the observational evidence for or against these predictions and (3) present new results on ionised outflows in AGN. The observational support for the “maintenance mode” of feedback is strong (caveat the details); AGN at the centre of massive halos appear to be regulating the cooling of hot gas, which could in turn control the levels of future star formation (SF) and black hole growth. In contrast, direct observational support for more rapid forms of feedback, which dramatically impact on SF (i.e., the “quasar mode”), remains elusive. From a systematic study of the spectra of ≈24 000 AGN we find that extreme ionised gas kinematics are common, and are most prevalent in radio bright AGN (L1.4 GHz > 103 W Hz−1). Follow-up IFU observations have shown that these extreme gas kinematics are extended over kilo-parsec scales. However, the co-existence of high-levels of SF, luminous AGN activity and radio jets raises interesting questions on the primary drivers and impact of these outflows. Galaxy-wide, high-mass outflows are being observed in an increasing number of AGN and are a plausible mechanism for the depletion of gas; however, there is still much work to be done to determine the physical processes that drive these outflows and to measure the level of impact that they have on their host galaxies.

We report the results from a systematic search for molecular (OH 119 μm) outflows with Herschel-PACS† in a sample of 43 nearby (z < 0.3) galaxy mergers, mostly ultraluminous infrared galaxies (ULIRGs) and QSOs. We find that the character of the OH feature (strength of the absorption relative to the emission) correlates with that of the 9.7-μm silicate feature, a measure of obscuration in ULIRGs. Unambiguous evidence for molecular outflows, based on the detection of OH absorption profiles with median velocities more blueshifted than −50 km s−1, is seen in 26 (70%) of the 37 OH-detected targets, suggesting a wide-angle (~ 145°) outflow geometry. Conversely, unambiguous evidence for molecular inflows, based on the detection of OH absorption profiles with median velocities more redshifted than +50 km s−1, is seen in only 4 objects, suggesting a planar or filamentary geometry for the inflowing gas. Terminal outflow velocities of ~ −1000 km s−1 are measured in several objects, but median outflow velocities are typically ~ −200 km s−1. While the outflow velocities show no statistically significant dependence on the star formation rate, they are distinctly more blueshifted among systems with large AGN fractions and luminosities [log (LAGN/L⊙) ≥ 11.8 ± 0.3]. The quasars in these systems play a dominant role in driving the molecular outflows. In contrast, the most AGN dominated systems, where OH is seen purely in emission, show relatively modest OH line widths, despite their large AGN luminosities, perhaps indicating that molecular outflows subside once the quasar has cleared a path through the obscuring material.

Low-luminosity radio galaxies, common in the local Universe, are associated with giant elliptical galaxies and typically with a FR I radio morphology. However, they are rare in flux-limited samples of distant radio-loud (RL) AGN due to a selection bias. Chiaberge et al. (2009) selected the first sizeable sample of FRI candidates at 1<z<3, in the COSMOS field. We study the Spectral Energy Distributions (SEDs) of this low radio power sample from the far-UV to the Mid-IR wavelengths. Our results show that the hosts of these high-z low-luminosity radio sources are old massive galaxies, similar to the local FR Is. However, for half of the sample the UV and MIR excesses indicate the possible significant contribution from star formation and/or nuclear activity, not seen in low-z FR Is. Our sources display a wide variety of properties: from possible quasars at the highest luminosities, to low-luminosity old galaxies.

We present the results of recent studies on the co-evolution of galaxies and the supermassive black holes (SMBHs) using Herschel far-infrared and Chandra X-ray observations in the Boötes survey region. For a sample of star-forming (SF) galaxies, we find a strong correlation between galactic star formation rate and the average SMBH accretion rate in SF galaxies. Recent studies have shown that star formation and AGN accretion are only weakly correlated for individual AGN, but this may be due to the short variability timescale of AGN relative to star formation. Averaging over the full AGN population yields a strong linear correlation between accretion and star formation, consistent with a simple picture in which the growth of SMBHs and their host galaxies are closely linked over galaxy evolution time scales.

The HeRGÉ (Herschel Radio Galaxy Evolution) project consists of a sample of 70 radio galaxies in the range 1 < z < 5.2. They benefit from continuous coverage from 3 to 870μm with Spitzer, Herschel and sub-mm ground-based instruments (SCUBA, LABOCA). As a calorimeter, IR is an excellent proxy to estimate the contribution of both AGN and starburst, making of radio galaxies perfect candidates to provide new insights into the relationship between AGN and their host galaxies. The IR SED fitting with empirical templates reveals that radio galaxies are luminous and that their black holes and their host galaxies are not growing simultaneously. Extending the SED to optical/near-IR on a subsample of 12 radio galaxies spanning 1 < z < 4 reveal the necessity of three components to reproduce the observations. Making use of the evolutionary code PEGASE.3 and an AGN torus model, we are able to estimate parameters from the AGN torus, the evolved stellar population and the starburst (SB). They reveal that radio galaxies are massive, evolved, forming the bulk of their mass at very high redshift in a short timescale, but experience episodic, strong SB events, often associated with an AGN activity.