Nico Winkel

Reverberation mapping (RM) determines the mass of black holes (BHs) in active galactic nuclei (AGNs) by resolving the BH gravitational sphere of influence in the time domain. Recent RM campaigns have yielded direct BH masses through dynamical modeling for a sample of 32 objects, spanning a wide range of AGN luminosities and BH masses. In addition, accurate BH masses have been determined by spatially resolving the broad-line region with GRAVITY for a handful of AGNs. Here, we present a detailed analysis of Hubble Space Telescope images using surface-brightness profile fitting with state-of-the-art programs. We derive AGN luminosity and host-galaxy properties, such as radii and luminosities for the spheroid, disk, and bar (if present). The spheroid effective radii are used to measure stellar velocity dispersion from integral-field spectroscopy. Since the BH masses of our sample do not depend on any assumption of the virial factor needed in single-epoch spectroscopic mass estimates, we can show that the resulting scaling relations between the mass of the supermassive BHs and their host galaxies match those of quiescent galaxies, naturally extending to lower masses in these (predominantly) spiral galaxies. We find that the inner AGN orientation, as traced by the broad-line region inclination angle, is uncorrelated with the host-galaxy disk. Our sample has the most direct and accurate M _BH measurements of any AGN sample and provides a fundamental local benchmark for studies of the evolution of massive BHs and their host galaxies across cosmic time.

Reverberation mapping (RM) determines the mass of black holes (BH) in active galactic nuclei (AGNs) by resolving the BH gravitational sphere of influence in the time domain. Recent RM campaigns yielded direct BH masses through dynamical modeling for a sample of 32 objects, spanning a wide range of AGN luminosities and BH masses. In addition, accurate BH masses have been determined by spatially resolving the broad-line region with GRAVITY for a handful of AGNs. Here, we present a detailed analysis of Hubble Space Telescope images using surface-brightness profile fitting with state-of-the-art programs. We derive AGN luminosity and host-galaxy properties, such as radii and luminosities for spheroid, disk, and bar (if present). The spheroid effective radii were used to measure stellar velocity dispersion from integral-field spectroscopy. Since the BH masses of our sample do not depend on any assumption of the virial factor needed in single-epoch spectroscopic mass estimates, we can show that the resulting scaling relations between the mass of the supermassive BHs and their host galaxies match those of quiescent galaxies, naturally extending to lower masses in these (predominantly) spiral galaxies. We find that the inner AGN orientation, as traced by the broad-line region inclination angle, is uncorrelated with the host-galaxy disk. Our sample has the most direct and accurate MBH measurements of any AGN sample and provides a fundamental local benchmark for studies of the evolution of massive black holes and their host galaxies across cosmic time.

We present optical integral-field spectroscopic data of ten nearby (0.02 ≤ z ≤ 0.05) Seyfert 1 galaxies taken with the Keck Cosmic Web Imager. We map the spatially resolved kinematics of the [O iii] gas and stars, and investigate the alignments between their global kinematic position angles (PAs). Large-scale gas motions are primarily dominated by rotation and are kinematically aligned with the stars (ΔPA ≤ 30°). However, eight galaxies exhibit nonrotational kinematic signatures (e.g., kinematic twists, possible outflows) in their ionized gas velocity fields near the nucleus. We compare aperture-wide measurements of the gas and stellar velocity dispersions (σ _gas and σ _⋆) to test the use of the width of the [O iii] line core as a surrogate for σ _⋆. Direct comparisons between σ _gas and σ _⋆ show that σ _gas tends to underestimate σ _⋆, and thus is not a reliable tracer of σ _⋆ for our selected galaxies. We measure the extent of the narrow-line region (NLR) using several definitions, resulting in sizes of ∼0.1–10 kpc. For a given [O iii] luminosity, our NLR sizes derived from the [O iii]/Hβ flux ratio or an [O iii] isophotal radius are an order of magnitude larger than those measured from past imaging data.

Context. Supermassive black holes (SMBHs) grow primarily through gas accretion, observed as active galactic nuclei (AGNs). While mergers can drive luminous AGN episodes, secular processes may fuel a substantial portion of cosmic black hole growth. Whether these mechanisms can sustain high black hole accretion rates remains uncertain. Aims. The aim of this study is to identify the secular mechanism driving high SMBH accretion rates, by targeting a galaxy with a moderately massive SMBH, high central gas densities, accretion rates of a few percent of the Eddington limit, and gas kinematics resolved close to black-hole-dominated scales. Methods. A blind search led to the identification of NGC 4593, which is representative of the AGN population driving BH mass density growth since z = 1. Combining HST imaging, VLT/MUSE spectroscopy, and ALMA imaging, we resolve molecular and ionised gas kinematics close to the sphere of influence of the SMBH. Results. A prominent single-arm (“m = 1”) molecular gas spiral with log M_mol/M_⊙ = 8.1 ± 0.3 extends from 1.3 kpc down to the SMBH’s sphere of influence (1.7_−0.2^+0.5 pc). Star formation in the spiral is inefficient (SFR = 4.9 × 10⁻² M_⊙/yr, ⟨t_dep⟩=3.9 ± 0.6 Gyr), whereas the gas inflow rate exceeds the SFR by two orders of magnitude and is sufficient to sustain the current SMBH accretion rate for ≥35 Myr, enabling ∼10% SMBH growth. A young, lopsided stellar component (log M_⋆/M_⊙ = 7.5 − 9.3) exerts torques on the molecular gas, likely driving the gas inflow. This young stellar component may serve as both a cause and a product of sustained gas funnelling towards the SMBH. Conclusions. These findings provide evidence for the sustained secular m = 1 feeding mode at high SMBH accretion rates, linking kpc-scale gas dynamics to the black hole’s sphere of influence. This mechanism, consistent with simulation predictions, may represent a key contributor to SMBH growth in luminous AGNs since cosmic noon.

Context. Changing-look active galactic nuclei (CLAGNs) are accreting supermassive black hole systems that undergo variations in optical spectral type driven by major changes in accretion rate. The CLAGN Mrk 1018 has undergone two transitions, a brightening event in the 1980s and a transition back to a faint state over the course of 2–3 years in the early 2010s. Aims. We characterize the evolving physical properties of the source's inner accretion flow, particularly during the bright-to-faint transition, as well as the morphological properties of its parsec-scale circumnuclear gas. Methods. We modeled archival X-ray spectra from XMM-Newton, Chandra, Suzaku, and Swift using physically motivated models to characterize X-ray spectral variations and tracked the Fe Kα line flux. We also quantified Mrk 1018's long-term multiwavelength spectral variability from optical/UV to the X-rays. Results. Over the duration of the bright-to-faint transition, the UV and hard X-ray flux fell by differing factors, roughly 24 and 8, respectively. The soft X-ray excess faded and was not detected by 2021. In the faint state, when the Eddington ratio drops to log(L_bol/L_Edd)≲−1.7, the hot X-ray corona photon index shows a “softer-when-fainter” trend that is similar to what is seen in some black hole X-ray binaries and samples of low-luminosity AGNs. Finally, the Fe Kα line flux has dropped by only half the factor of the drop in the X-ray continuum. Conclusions. The transition from the bright state to the faint state is consistent with the inner accretion flow transitioning from a geometrically thin disk to an ADAF-dominated state, with the warm corona disintegrating or becoming energetically negligible, while the X-ray-emitting hot flow becomes energetically dominant. Meanwhile, narrow Fe Kα emission has not yet fully responded to the drop in its driving continuum, likely because its emitter extends up to roughly 10 pc.

The origin of the tight scaling relation between the mass of supermassive black holes (SMBHs; M _BH) and their host-galaxy properties remains unclear. Active galactic nuclei (AGNs) probe phases of ongoing SMBH growth and offer the only opportunity to measure M _BH beyond the local Universe. However, determining an AGN's host galaxy's stellar velocity dispersion, σ _⋆, and its galaxy dynamical mass, M _dyn, is complicated by AGN contamination, aperture effects, and different host-galaxy morphologies. We select a sample of AGNs for which M _BH has been independently determined to high accuracy by state-of-the-art techniques: dynamical modeling of the reverberation signal and spatially resolving the broad-line region with the Very Large Telescope Interferometer/GRAVITY. Using integral-field spectroscopic observations, we spatially map the host-galaxy stellar kinematics across the galaxy and bulge effective radii. We find that the dynamically hot component of galaxy disks correlates with M _BH; however, the correlations are tightest for aperture-integrated σ _⋆ measured across the bulge. Accounting for the different M _BH distributions, we demonstrate—for the first time—that AGNs follow the same M _BH–σ _⋆ and M _BH–M _bulge,dyn relations as quiescent galaxies. We confirm that the classical approach of determining the virial factor as a sample average, yielding log f = 0.65 ± 0.18 , is consistent with the average f from individual measurements. The similarity between the underlying scaling relations of AGNs and quiescent galaxies implies that the current AGN phase is too short to have altered black hole masses on a population level. These results strengthen the local calibration of f for measuring single-epoch M _BH in the distant Universe.

We present a case study of HE 0040-1105, an unobscured radio-quiet active galactic nucleus (AGN) at a high accretion rate of λ _Edd = 0.19 ± 0.04. This particular AGN hosts an ionized gas outflow with the largest spatial offset from its nucleus compared to all other AGNs in the Close AGN Reference Survey. By combining multiwavelength observations from the Very Large Telescope/MUSE, Hubble Space Telescope/Wide Field Camera 3, Very Large Array, and European VLBI Network, we probe the ionization conditions, gas kinematics, and radio emission from host galaxy scales to the central few parsecs. We detect four kinematically distinct components, one of which is a spatially unresolved AGN-driven outflow located within the central 500 pc, where it locally dominates the interstellar medium conditions. Its velocity is too low to escape the host galaxy’s gravitational potential, and may be re-accreted onto the central black hole via chaotic cold accretion. We detect compact radio emission in HE 0040-1105 within the region covered by the outflow, varying on a timescale of ∼20 yr. We show that neither AGN coronal emission nor star formation processes wholly explain the radio morphology/spectrum. The spatial alignment between the outflowing ionized gas and the radio continuum emission on 100 pc scales is consistent with a weak jet morphology rather than diffuse radio emission produced by AGN winds. >90% of the outflowing ionized gas emission originates from the central 100 pc, within which the ionizing luminosity of the outflow is comparable to the mechanical power of the radio jet. Although radio jets might primarily drive the outflow in HE 0040-1105, radiation pressure from the AGN may contribute to this process.

Context. The interaction between active galactic nuclei (AGNs) and their host galaxies is scarcely resolved. Narrow-line Seyfert 1 (NLS1) galaxies are believed to represent AGN at early stages of their evolution and to allow one to observe feeding and feedback processes at high black hole accretion rates. Aims. We aim to constrain the properties of the ionised gas outflow in Mrk 1044, a nearby super-Eddington accreting NLS1. Based on the outflow energetics and the associated timescales, we estimate the outflow’s future impact on the ongoing host galaxy star formation on different spatial scales. Methods. We applied a spectroastrometric analysis to observations of Mrk 1044’s nucleus obtained with the adaptive-optics-assisted narrow field mode of the VLT/MUSE instrument. This allowed us to map two ionised gas outflows traced by [O III], which have velocities of −560 ± 20 km s⁻¹ and −144 ± 5 km s⁻¹. Furthermore, we used an archival spectrum from the Space Telescope Imaging Spectrograph on HST to identify two Ly-α absorbing components that escape from the centre with approximately twice the velocity of the ionised gas components. Results. Both [O III] outflows are spatially unresolved and located close to the AGN (< 1 pc). They have gas densities higher than 10⁵ cm⁻³, which implies that the BPT diagnostic cannot be used to constrain the underlying ionisation mechanism. We explore whether an expanding shell model can describe the velocity structure of Mrk 1044’s multi-phase outflow. In the ionised gas emission, an additional outflowing component, which is spatially resolved, is present. It has a velocity of −211 ± 22 km s⁻¹ and a projected size of 4.6 ± 0.6 pc. Our kinematic analysis suggests that significant turbulence is present in the interstellar medium around the nucleus, which may lead to a condensation rain, potentially explaining the efficient feeding of Mrk 1044’s AGN. Within the innermost 0.5″ (160 pc), we detect modest star formation hidden by the beam-smeared emission from the outflow. Conclusions. We estimate that the multi-phase outflow was launched < 10⁴ yr ago. Together with the star formation in the vicinity of the nucleus, this suggests that Mrk 1044’s AGN phase started only recently. The outflow carries enough mass and energy to impact the host galaxy star formation on different spatial scales, highlighting the complexity of the AGN feeding and feedback cycle in its early stages.

Context.The host galaxy conditions for rapid supermassive black hole growth are poorly understood. Narrow-line Seyfert 1 (NLS1) galaxies often exhibit high accretion rates and are hypothesized to be prototypes of active galactic nuclei (AGN) at an early stage of their evolution.Aims.We present adaptive optics (AO) assisted VLT MUSE NFM observations of Mrk 1044, the nearest super-Eddington accreting NLS1. Together with archival MUSE WFM data, we aim to understand the host galaxy processes that drive Mrk 1044’s black hole accretion.Methods.We extracted the faint stellar continuum emission from the AGN-deblended host and performed spatially resolved emission line diagnostics with an unprecedented resolution. Combining both MUSE WFM and NFM-AO observations, we used a kinematic model of a thin rotating disk to trace the stellar and ionized gas motion from 10 kpc galaxy scales down to ∼30 pc around the nucleus.Results.Mrk 1044’s stellar kinematics follow circular rotation, whereas the ionized gas shows tenuous spiral features in the center. We resolve a compact star-forming circumnuclear ellipse (CNE) that has a semi-minor axis of 306 pc. Within this CNE, the gas is metal-rich and its line ratios are entirely consistent with excitation by star formation. With an integrated star formation rate of 0.19 ± 0.05 M_⊙ yr⁻¹, the CNE contributes 27% of the galaxy-wide star formation.Conclusions.We conclude that Mrk 1044’s nuclear activity has not yet affected the circumnuclear star formation. Thus, Mrk 1044 is consistent with the idea that NLS1s are young AGN. A simple mass budget consideration suggests that the circumnuclear star formation and AGN phase are connected and the patterns in the ionized gas velocity field are a signature of the ongoing AGN feeding.