We present a mid‐infrared investigation of the scaling relations between supermassive black hole masses (MBH) and the structural parameters of the host spheroids in local galaxies. This work is based on 2D bulge‐disc decompositions of Spitzer/IRAC 3.6 μm images of 57 galaxies with MBH estimates. We first verify the accuracy of our decomposition by examining the Fundamental Plane (FP) of spheroids at 3.6 μm. Our estimates of effective radii (Re) and average surface brightnesses, combined with velocity dispersions from the literature, define a FP relation consistent with previous determinations but doubling the observed range in Re. None of our galaxies is an outlier of the FP, demonstrating the accuracy of our bulge‐disc decomposition which also allows us to independently identify pseudo‐bulges in our sample. We calibrate M/L at 3.6 μm by using the tight Mdyn–Lbul relation (∼0.1 dex intrinsic dispersion) and find that no colour corrections are required to estimate the stellar mass. The 3.6 μm luminosity is thus the best tracer of stellar mass yet studied. We then explore the connection between MBH and bulge structural parameters (luminosity, mass, effective radius). We find tight correlations of MBH with both 3.6 μm bulge luminosity and dynamical mass (MBH/Mdyn∼ 1/1000), with intrinsic dispersions of ∼0.35 dex, similar to the MBH–σ relation. Our results are consistent with previous determinations at shorter wavelengths. By using our calibrated M/L, we rescale MBH–Lbul to obtain the MBH–M★ relation, which can be used as the local reference for high‐z studies which probe the cosmic evolution of MBH–galaxy relations and where the stellar mass is inferred directly from luminosity measurements. The analysis of pseudo‐bulges shows that four out of nine lie on the scaling relations within the observed scatter, while those with small MBH are significantly displaced. We explore the different origins for such behaviour while considering the possibility of nuclear morphological components not reproduced by our 2D decomposition.

Context. The AGN bolometric correction is a key element to understand BH demographics and compute accurate BH accretion histories from AGN luminosities. However, current estimates still differ from each other by up to a factor of two to three, and rely on extrapolations at the lowest and highest luminosities. Aims. Here we revisit this fundamental issue presenting general hard X-ray (K X ) and optical (K O ) bolometric corrections, computed combining several AGN samples spanning the widest (about 7 dex) luminosity range ever used for this kind of studies. Methods. We analysed a total of ∼ 1000 type 1 and type 2 AGN for which a dedicated SED-fitting has been carried out. Results. We provide a bolometric correction separately for type 1 and type 2 AGN; the two bolometric corrections results to be in agreement in the overlapping luminosity range and therefore, for the first time, a universal bolometric correction for the whole AGN sample (both type 1 and type 2) has been computed. We found that K X is fairly constant at log(L BOL /L ⊙ ) < 11, while it increases up to about one order of magnitude at log(L BOL /L ⊙ ) ∼ 14.5. A similar increasing trend has been observed when its dependence on either the Eddington ratio or the BH mass is considered, while no dependence on redshift up to z ∼ 3.5 has been found. On the contrary, the optical bolometric correction appears to be fairly constant (i.e. K O ∼ 5) whatever is the independent variable. We also verified that our bolometric corrections correctly predict the AGN bolometric luminosity functions. According to this analysis, our bolometric corrections can be applied to the whole AGN population in a wide range of luminosity and redshift.

Models and observations suggest that both power and effects of AGN feedback should be maximised in hyper-luminous (L Bol > 10 47 erg s −1 ) quasars, i.e. objects at the brightest end of the AGN luminosity function. In this paper, we present the first results of a multi-wavelength observing program, focusing on a sample of WISE/SDSS selected hyper-luminous (WISSH) broad-line quasars at z ≈ 1.5 − 5. The WISSH quasars project has been designed to reveal the most energetic AGN-driven outflows, estimate their occurrence at the peak of quasar activity, and extend the study of correlations between outflows and nuclear properties up to poorlyinvestigated, extreme AGN luminosities, i.e. L Bol ∼ 10 47 − 10 48 erg s −1 . We present near-infrared, long-slit LBT/LUCI1 spectroscopy of five WISSH quasars at z ≈ 2.3 − 3.5, showing prominent [OIII] emission lines with broad (FWHM ∼ 1200 − 2200 km s −1 ) and skewed profiles. The luminosities of these broad [OIII] wings are the highest measured so far, with L broad [OIII] 5× 10 44 erg s −1 , and reveal the presence of powerful ionised outflows with associated mass outflow ratesṀ 1700 M ⊙ yr −1 and kinetic powersĖ kin 10 45 erg s −1 . Although these estimates are affected by large uncertainties, due to the use of [OIII] as tracer of ionized outflows and the very basic outflow model we assume, these results suggest that the AGN is highly efficient in pushing outwards large amounts of ionised gas in our hyper-luminous targets. Furthermore, the mechanical outflow luminosities measured for WISSH quasars correspond to higher fractions (∼ 1 − 3 %) of L Bol than those derived for AGN with lower L Bol . Our targets host very massive (M BH 2 × 10 9 M ⊙ ) black holes which are still accreting at a high rate (i.e. a factor of ∼ 0.4 − 3 of the Eddington limit). These findings clearly demonstrate that WISSH quasars offer the opportunity of probing the extreme end of both luminosity and SMBH mass functions and revealing powerful ionised outflows able to affect the evolution of their host galaxies.

We report on the serendipitous discovery of a z = 4.0, M 1500 = −22.20 star-forming galaxy (Ion3) showing copious Lyman continuum (LyC) leakage (∼ 60% escaping), a remarkable multiple peaked Lyα emission, and significant Lyα radiation directly emerging at the resonance frequency. This is the highest redshift confirmed LyC emitter in which the ionising and Lyα radiation possibly share a common ionised channel (with N HI < 10 17.2 cm −2 ). Ion3 is spatially resolved, it shows clear stellar winds signatures like the P-Cygni Nvλ1240 profile, and has blue ultraviolet continuum (β = −2.5 ± 0.25, F λ ∼ λ β ) with weak low-ionisation interstellar metal lines. Deep VLT/HAWKI Ks and Spitzer/IRAC 3.6µm and 4.5µm imaging show a clear photometric signature of the Hα line with equivalent width of 1000Å rest-frame emerging over a flat continuum (Ks−4.5µm 0). From the SED fitting we derive a stellar mass of 1.5 × 10 9 M , SFR of 140 M yr −1 and age of ∼ 10 Myr, with a low dust extinction, E(B-V) 0.1, placing the source in the starburst region of the SFR−M * plane. Ion3 shows similar properties of another LyC emitter previously discovered (z = 3.21, Ion2, Vanzella et al. 2016). Ion3 (and Ion2) represents ideal high-redshift reference cases to guide the search for reionising sources at z > 6.5 with JWST.

In our first paper, we performed a detailed (i.e., bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decomposition of 66 galaxies, with directly measured black hole masses, M BH , imaged at 3.6 m m with Spitzer. Our sample is the largest to date and, for the first time, the decompositions were checked for consistency with the galaxy kinematics. We present correlations between M BH and the host spheroid (and galaxy) luminosity, L sph (and L gal ), and also stellar mass, M .,sph * While most previous studies have used galaxy samples that were overwhelmingly dominated by high-mass, early-type galaxies, our sample includes 17 spiral galaxies, half of which have M M 10 , argued by some to be pseudo-bulges, are not offset to lower M BH from the correlation defined by the current bulge sample with n 2; sph > and (3)L sph and L gal correlate equally well with M BH , in terms of intrinsic scatter, only for early-type galaxies-once reasonable numbers of spiral galaxies are included, the correlation with L sph is better than that with L gal .