Active Galactic Nuclei XVI: A Sea of Discoveries

14 Jun 2026, 18:00 → 19 Jun 2026, 23:00 UTC

Sala Conferenze presso Autorità di Sistema Portuale (Brindisi)

Francesca Panessa (Istituto Nazionale di Astrofisica (INAF)), Stefano Bianchi

The "Active Galactic Nuclei XVI: A Sea of Discoveries" conference continues a three-decade-long tradition of bringing together experts to share and discuss the latest research in Active Galactic Nuclei (AGN). Held in Brindisi, in the heart of Puglia, this meeting serves as an invaluable opportunity for experts to not only review the current status of the field, but also to exchange ideas, forge new collaborations, and push the boundaries of AGN research.

The Italian AGN community is growing and highly active, with its interests expanding across a wide range of astrophysical topics. This meeting will not only showcase the community's established expertise but also its burgeoning involvement in new research areas.

The scientific program will cover the following key topics:

1. Black Hole Accretion and Outflows: Focusing on the physics of accretion disks, the mechanisms driving high-velocity winds, and the geometry of circumnuclear regions.

2. Relativistic Jets and Particle Acceleration: Investigating the launching, collimation, and energetic processes within relativistic jets, including their composition and impact.

3. Black Holes Across the Mass Scale and Time-Domain Probes: Exploring the accretion and ejection coupling through analogies and differences between supermassive black holes, intermediate and stellar-mass compact objects and through transient sources (TDEs, QPEs, Changing-look, etc.).

4. Binary and Dual AGN Systems: Studying the observational signatures, dynamics, and gravitational wave implications of closely separated and merging black hole systems.

5. Multi-Messenger: Leveraging variability studies, gravitational waves, and high-energy neutrinos (multi-messenger astronomy) to understand the immediate vicinity of the central engine.

6. AGN Feedback and the Host Galaxy: Analyzing how AGN energy output (kinetic and radiative feedback) impacts star formation and gas distribution within the host galaxy and its surrounding dark matter halo.

7. The Early Growth of Supermassive Black Holes: Examining the formation, growth rates, and census of SMBHs in the high-redshift universe (z > 6) and their role in cosmic reionization.

8. Cosmological Implications and Large-Scale Environment: Discussing the role of AGN in structure formation and galaxy evolution models, including the effect of the large-scale environment on AGN activity.

9. Current and Future Facilities for AGN Science: Discussing the implementation and scientific exploitation of major current and future space-based and ground-based facilities with Italian involvement, focusing on maximizing their impact on AGN studies.

 

 

 

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timetable_150626_updated_posters_AGNXVI.pdf

Sunday 14 June

1 Registration Desk & Welcome Cocktail at Santa Spazio Culturale (Yeahjasi) - Ex convento di Santa Chiara

Social events: Presentation "Rigenerazione olivicola post-Xylella in Provincia di Brindisi" (Presidente Coldiretti Brindisi) and Piano Concert

2 Presentation: "Rigenerazione olivicola post-Xylella in Provincia di Brindisi"

Speaker: Giovanni Ripa (Presidente Coldiretti Brindisi)

3 Piano Concert: Aksinja Gioia

Social events: Claudia Di Cera: "Archeoastronomia: un viaggio, scientifico, nell’archeoastronomia"

Monday 15 June

4 Registration

Institutional Welcomes and Opening Remarks

Convener: Dr Francesca Panessa (Istituto Nazionale di Astrofisica (INAF))

5 Institutional Welcomes (Mayor of Brindisi)

Speaker: Giuseppe Marchionna

6 SEZIONE INAF Università del Salento

Speaker: Prof. Francesco Strafella

7 Opening Remarks

Speaker: Fabrizio Fiore

S1 - Black Hole Accretion and Outflows: Focusing on the physics of accretion disks, the mechanisms driving high-velocity winds, and the geometry of circumnuclear regions

Convener: Paola Marziani (Istituto Nazionale di Astrofisica (INAF))

8 (Review) The X-ray Corona and its dependence on AGN Accretion Properties

X-ray-emitting plasma is a ubiquitous feature of accreting massive black holes, but several of its properties and the mechanisms that power it remain unknown. In my talk, I will give an overview of recent findings on the properties of X-ray coronae and how they change with the Eddington ratio, including results from large studies of extremely variable AGN. I will also review recent millimeter studies carried out with ALMA that have identified a population of non-thermal electrons, possibly associated with the corona, that produce self-absorbed synchrotron radiation detected at 100-200 GHz.

Speaker: Prof. Claudio Ricci (University of Geneva)

9 Tracing disc-corona coupling and ionising output of quasars across the Lx-Luv plane

Unobscured, radio-quiet quasars define a tight correlation between X-ray and UV luminosities (the Lx-Luv relation), widely interpreted as the signature of disc-corona coupling. However, the physical origin of the scatter around the relation remains unclear, with X-ray-weak quasars representing its most extreme deviations. We assemble a statistically robust sample of more than 5000 quasars with homogeneous SDSS UV/optical and Chandra X-ray spectroscopy, and use it to explore how the properties of the central engine and its ionising output, as traced by high-ionisation gas, vary across the Lx-Luv plane. We focus on the C IV, He II, and [O III] emission lines, which trace gas on parsec and kiloparsec scales, and analyse how their luminosities, equivalent widths, and blueshifts vary as a function of LX, LUV, αox, and Δαox, the offset from the relation. We find that X-ray-weak quasars are, on average, over-luminous in high-ionisation lines at fixed LX, and that line strength and kinematics vary systematically with Δαox , most clearly for C IV and [O III]. These trends suggest that the offset from the Lx-Luv relation traces not only the disc-corona balance, but also the ionising continuum seen by gas on both BLR and NLR scales. We also present a complementary machine-learning analysis aimed at identifying which UV spectral properties, particularly those of C IV, are most predictive of the offset from the relation in a multivariate framework.

Speaker: Susanna Bisogni (INAF-IASF Milano)

11:00 Coffee break

S1 - Black Hole Accretion and Outflows: Focusing on the physics of accretion disks, the mechanisms driving high-velocity winds, and the geometry of circumnuclear regions

Convener: Paola Marziani (Istituto Nazionale di Astrofisica (INAF))

10 (Highlight) The Quasar X-ray View at the Epoch of Reionization: Implications for Early Black Hole Accretion, AGN Emissivity, and Future Surveys

Shedding light on the nuclear properties of $z>6$ quasars (QSOs) powered by supermassive black holes (SMBHs) with masses $>10^9~M_\odot$​ is fundamental to understand their rapid formation during the Epoch of Reionization (EoR). Probing the innermost regions of these QSOs via X-ray emission, at just a few tens of gravitational radii, provides the most direct window into the growing SMBH.

We present results from HYPERION, an unprecedented $\sim$700-hour XMM-Newton Heritage Program targeting 18 luminous QSOs at $z\approx6-7.5$ selected for their extreme SMBH growth. Our findings reveal a strikingly new regime for the nuclear properties of these early-formed QSOs: their X-ray continuum slopes ($\Gamma$) are significantly steeper than those of analogous QSOs at $z<6$. By investigating correlations between $\Gamma$ and UV-derived properties, we identify a significant link between the X-ray slope and the velocity of nuclear AGN-driven ionized winds, potentially indicative of fast SMBH accretion.

This investigation is further expanded by a new 150-hour XMM-Newton Large Program which, combined with archival X-ray data, brings the total sample to 30 QSOs and extends to sources with slower growth rates. The data confirm that steep X-ray slopes are a ubiquitous feature of the $z\gtrsim6$ QSOs population at EoR, independent of the SMBH growth-rate selection.

The enhanced X-ray spectral steepness in these high-redshift quasars results in significantly fainter X-ray fluxes than those predicted by a canonical X-ray spectral slope. We show that if the fainter $z\gtrsim 5-6$ AGN population exhibits similarly steep spectra, it would provide a natural explanation for the widespread lack of X-ray emission observed for the AGN population emerging from the JWST surveys.

Furthermore, we discuss how the persistence of steep X-ray spectra in the whole AGN population would carry critical implications for future EoR X-ray surveys. Indeed, non-canonical spectral shapes if not accounted for properly, can significantly bias detectability and flux/luminosity estimates, necessitating a recalibration of current survey strategies.

Speaker: Luca Zappacosta (Istituto Nazionale di Astrofisica (INAF))

11 Outflows and Radio-Quiet AGN: Radio Emission as a Feedback Tracer Across Cosmic Time

Outflows in Active-Galactic Nuclei (AGN), either in the form of winds or jets, are now routinely detected at all ionisation states, velocities and distances from the inner SMBH. These range from the sub-relativistic (0.1 − 0.25c), highly ionised, ultra-fast outflows (UFOs), arising at few gravitational radii, down to the slower (∼ 500 − 2000 km/s) outflows detected on kpc-scales, in the atomic and molecular gas phases.
Because of their potential ubiquitousness, winds and jets are frequently proposed as a preferential channel for AGN-feedback, successfully regulating both accretion and ejection onto the central black hole, quenching star formation and potentially explaining the scaling relations between black hole mass and host galaxy properties.
In this context, radio-quiet AGN, much more common than their jet-dominated radio-loud counterpart, provide a unique window into feedback processes. Indeed, because the radio emission in faint radio sources is not buried in that of a relativistic jet, it is possible to try to disentangle between various processes, including star-formation activity, coronal activity, accretion disk winds and small-scale jets. In particular investigating the impact of low-power radio jets and winds on the host galaxy and their relation with outflows in different gas phases is fundamental for our understanding of AGN feedback and galaxy evolution.
In this talk I will emphasise the value of both single-object and statistical studies of the origin of radio emission in radio-quiet AGN. I will show key results from the X-ray-selected radio-quiet AGN of SUBWAYS (z ~0.1–0.5, $L_{bol}~10^{45-46}$), where UFOs have been detected as Fe K-shell X- ray absorption-line features. Radio follow-up observations show that the majority of the AGN in the sample exhibit extended radio emission and steep radio spectra, consistent with hosting radio outflows. This may hint at an interesting, and still poorly-understood, connection between nuclear and large scale outflows.
Finally, I will also present some preliminary results on XID2028, an obscured quasar at z=1.59, where the combination of VLA, MIRI, NIRspec and ALMA data provides stronger constraints on the nature of the outflows, and their impact on the host galaxy. These results confirm that low-power jets or winds can play a relevant role in AGN feedback.

Speaker: Elisa Amenta (Istituto Nazionale di Astrofisica (INAF))

12 New X-ray Insights on the Torus Geometry and AGN Self-Regulation Processes

In this talk, I will present a review of the most recent results obtained by the Clemson-INAF CT-AGN collaboration. This project is based on the Palermo Swift-BAT catalog: by taking advantage of Swift-BAT effectiveness in detecting heavily obscured AGN at z~0, our group performed a multi-year, multi X-ray telescope effort aimed at obtaining a complete census of the obscured AGN population in the local Universe, while at the same time characterizing with unprecedented quality the properties of heavily obscured accreting supermassive black holes (SMBHs).
In particular, I will discuss the most recent developments of the project, and how we are working on building a large sample of heavily obscured AGN with multi-epoch X-ray observations, that are needed to characterize the properties of the clumpy medium surrounding accreting SMBHs, as well as to understand the complex feeding-feedback interplay which takes place between the SMBH and its host galaxy.

Speaker: Stefano Marchesi (Università di Bologna)

13 Cosmic Tides: Relativistic Disk Winds and the Accretion–Ejection Coupling in AGN

Ultra-fast outflows (UFOs) from accreting supermassive black holes provide a direct probe of the coupling between inflowing matter and powerful winds emerging from the inner accretion flow. These relativistic disk winds are now recognized as a key ingredient linking black hole accretion physics to feedback on galactic environments. Recent high-resolution spectroscopy with XRISM/Resolve reveals complex absorption structures with multiple discrete velocity components and a clumpy, multiphase medium. These observations place new constraints on wind geometry, launching radii, and energetics in high-accretion regimes, supporting scenarios in which stratified disk winds originate close to the innermost stable circular orbit. Population studies of large AGN samples further show that UFO properties correlate with spectral line width, equivalent width, and outflow velocity, pointing to inhomogeneous, multi-component winds shaped by radiation, magnetic fields, and turbulence. A uniform meta-analysis of radio-quiet and radio-loud AGN indicates that powerful winds arise across both classes, suggesting a broadly shared physical mechanism operating in the central engine. Together, these results highlight how relativistic disk winds trace the accretion–ejection coupling in active galactic nuclei and provide an efficient channel for transferring energy from the inner accretion flow to the host galaxy. In this talk, I will discuss how these cosmic tides of gas connect black hole accretion to galaxy-scale feedback, and the prospects for new missions to further unveil the physics of black hole winds.

Speaker: Prof. Francesco Tombesi (Tor Vergata University of Rome & INAF)

14 Unveiling BLR Scale Outflows: Models for the Era of High Resolution X-ray Spectroscopy

XRISM has provided an unprecedented view of the emission and absorption lines in the X-ray. Notably, early results showed significant complexity to the Fe-Kalpha line profile in AGN, with clear contributions from at least three emitting structures: an inner disc, intermediary broad line region (BLR), and an outer torus. This poses a new challenge for the modelling of the emission lines, which will only become more prominent with NewAthena. While fast sophisticated models exist for the disc line-profiles, large scale-height material is typically much more complex. In this talk I will present an analytic, yet physically motivated, approach for the emission line profiles from outflowing BLR scale material, motivated on reverberation and gravity+ studies which suggest at times an outflowing BLR. I will show that this gives a physically motivated, yet computationally fast, model for the intermediary component to Fe-Kalpha seen in the XRISM data, and demonstrate its application using the XRISM observations of NGC 4151. I will finish by discussing the future outlook, and how this approach can be extended for NewAthena to map not only the line profile but also its variability.

Speaker: Scott Hagen (Istituto Nazionale di Astrofisica (INAF))

15 First time-evolving ionisation analysis of the X-ray spectrum of NGC 4051: energetic, distance and a Broad Line-wind unification scenario

In this talk, I'll present a new application of the Time-Evolving PhotoIonisation Device (TEPID) code to a time-resolved NuSTAR+XMM-Newton spectrum of NGC 4051 from 2018. This nearby Seyfert I AGN is an ideal laboratory of the innermost accretion scale thanks to its brightness and wealth of spectroscopic features, from the optical to the X-rays. It hosts three disk winds with increasing velocity, ionisation and density, routinely detected in all the X-ray observations over the last 20 years.
Thanks to our advanced modeling, we have been able to accurately derive the gas number densities $n_H$ for the first time. This is a fundamental quantity to accurately probe such winds, however it is totally degenerate when assuming time-equilibrium ionisation and is indeed poorly known in all kind of compact, optically unresolved sources. Together with the usual spectroscopic diagnostics - $N_H, \xi, v_{out}$ , ... - , the gas number density allows to accurately determine the wind geometry and energetics without a-priori assumptions.
This allows to locate such winds in the optical Broad Line Region (around 0.005 parsecs) and lead to a coherent picture of all the gravitational-bound and outflowing structures around the accretion disc, from cold (Fe K$\alpha$) reflection to optical and UV virialised emission, up to the X-ray outflows.
I'll also illustrate the foreseen improvement with the high-resolution instrument Resolve onboard XRISM and the upcoming X-IFU onboard NewAthena.

Speaker: Alfredo Luminari (Istituto Nazionale di Astrofisica (INAF))

13:05 Lunch break (lunch is not provided as part of the event)

S1 - Black Hole Accretion and Outflows: Focusing on the physics of accretion disks, the mechanisms driving high-velocity winds, and the geometry of circumnuclear regions

Convener: Alessandra Lamastra (Istituto Nazionale di Astrofisica (INAF))

16 Discovery of ultra-fast outflows with vout > 0.3c in local, bright AGN

Ultra-fast outflows are highly ionized thick winds with characteristic absorption features (FeXXV and FeXXVI at 6.67-6.97 keV rest-frame) in the hard X-ray band, strongly blue-shifted by the extreme outflow velocities. These quasi-relativistic winds are thought to be the most promising mechanism powering AGN feedback, influencing the SMBH/host galaxy co-evolution. Assessing the relation between UFO velocity and AGN power, and the maximum velocity achievable by UFOs, is crucial to determine the launching mechanism of nuclear winds (i.e., radiation vs. magnetic driving). While few high-z luminous QSOs do show UFOs with velocities up to 0.4-0.6c, in the local Universe we have been limited so far by the background noise, shaping the canonical band limit of 10 keV, corresponding to a maximum velocity detectable of ~0.2c. We will present the first systematic XMM study on 33 bright sources to search for UFOs in the 7-12 keV band. Particular care has been dedicated to assessing the impact of the background with three different techniques employed. Our extension to E>10 keV in the search for UFOs has led to the detection of four previously unknown UFOs with very high velocities (v>0.3c), confirming that local Seyferts do show such high velocity UFOs. Discovering high-energy UFOs at low redshift and luminosity will influence our current knowledge on the linear correlation between bolometric luminosity of AGN and the outflow velocity of the winds.

Speaker: Ms Laura Borrelli

17 Beyond the dust: probing AGN-driven molecular outflows and phase-dependent extinction in ULIRGs

Understanding the structure and physical conditions of the active galactic nucleus (AGN) is essential for tracing how AGN interact with their host galaxies. High resolution multi-wavelength observations are required to probe the obscuring region directly, yet heavily dust-enshrouded systems often lack proper tracers. JWST overcomes many of these limitations, providing unprecedented sensitivity to the molecular gas that shapes torus obscuration and drives feedback. I will present JWST MIRI/MRS observations of the nearby ULIRG IRAS 07251 (~400 Mpc), selected for its exceptionally rich mid-IR molecular spectrum and extreme cosmic-ray ionization rate (ζH₂ ~10¹⁴ s⁻¹). The MIRI/MRS spectrum reveals numerous absorption features from ro-vibrational transitions of molecules (e.g., HCN v₂, HC₃N v₅, HCO⁺ v₂, N₂H⁺ v₂, HCNH⁺ v₄), arising from a compact shell located ~20–75 pc from the nucleus. These molecules exhibit column densities of ~10¹⁵–10¹⁸ cm⁻², rotational temperatures of 40–180 K, and outflow velocity of ~160 km/s corresponding to a mass outflow rate of 90–330 M⊙/yr. This warm molecular outflow is potentially tracing the base of the larger-scale cold molecular outflow previously detected in this galaxy. Comparing with predictions from chemical models, all detected species are consistent with originating in a cosmic-ray-dominated region. These results provide the first attempt to probe the physical and kinematic conditions of the material that is obscuring the AGN down to tens of parsecs, offering new insights into torus structure and feedback. I will also present spatially resolved maps of phase-specific obscuration levels in a sample of five nearby (U)LIRGs, demonstrating how JWST enables a new, multi-phase view of obscuration and of the molecular gas content of AGN.

Speaker: Giovanna Speranza (Instituto de física fundamental (IFF, CSIC))

18 Decoupling Line and Continuum Variability: Evidence for Disc Truncation in High-Accretion Quasars

The structure and physical properties of accretion discs in quasars remain poorly understood. A primary challenge lies in disentangling the degenerate roles of various physical parameters—such as black hole mass and spin, accretion rate, inclination, and environment—within the observed emission. A powerful method to mitigate these limitations is the analysis of variable quasars through multi-epoch observations, where spectral transitions are expected to be driven primarily by fluctuations in the accretion rate. In this study, I analyze the relationship between line and continuum luminosity using variable quasars with multiple SDSS spectroscopic observations. I focus on two primary samples: the first data release from the Black Hole Mapper project and sources observed by both the SDSS and BOSS spectrographs. Our findings indicate that an increase in continuum luminosity does not necessarily correspond to a proportional increase in line emission. Furthermore, we observe that objects with higher accretion rates appear, on average, cooler. These results suggest that elevated accretion rates may trigger disc truncation at larger inner radii—potentially driven by radiation-driven winds—resulting in lower disc temperatures while maintaining a constant ionizing
luminosity.

Speaker: Dr Chiara Niccolai (Scuola Superiore Meridionale)

19 Directly tracking the accretion disc formation around a supermassive black hole

Accretion onto supermassive black holes powers the most luminous persistent sources in the Universe: active galactic nuclei (AGN). Their emission is characterized by two distinct spectral components: thermal optical/ultraviolet radiation from an optically thick accretion disk and a power-law X-ray tail from a corona located in the innermost regions. Despite their prominence, how radiatively efficient disks form and couple to the hot corona remains poorly understood.

In this talk, I will discuss six years of simultaneous ultraviolet and X-ray monitoring of the nearby active galaxy ESO511-G030. We witness an increase of the ultraviolet flux from the disk by more than an order of magnitude over a timescale of less than three years, which we interpret as the real-time formation of an optically thick accretion disk.

I will show that at accretion rates higher than approximately 1% of the Eddington limit, the ultraviolet and X-ray data are tightly coupled, following the well-defined non-linear correlation found in more luminous quasars. However, below this threshold, this relation breaks down abruptly. I will argue that this suggests the evaporation of the inner accretion disk into a geometrically thick, optically thin hot flow. This represents a spectacular example of an accretion-state transition analogous to those observed in stellar-mass black holes, confirming the need for a paradigm change in the models of radiatively efficient accretion flows around supermassive black holes.

Speaker: Dr Riccardo Middei (INAF-OAR)

20 X-ray polarization in Radio-Quiet AGN: insights from the Wedge Corona model

The Imaging X-Ray Polarimetry Explorer (IXPE) is providing key measurements of the polarization of Radio-Quiet, unobscured AGN. In these sources the IXPE band (2–8 keV) is typically dominated by Comptonized emission from the corona, a cloud of relativistic electrons, whose shape and origin are debated, that up-scatters optical/UV photons from the accretion disk into X-rays. Because spectral data alone cannot uniquely distinguish between competing coronal geometries, polarimetry offers crucial additional constraints.
In this talk, after a brief review of leading corona models, I focus on the 'Wedge' corona: its geometry, plausible physical origins, and the spectral advantages it offers relative to alternative configurations. I then present results from extensive Monte Carlo relativistic simulations with the code MONK, examining how polarization signatures depend on key physical (e.g., black hole spin, coronal temperature, optical depth) and geometric parameters. Finally, I compare these simulated polarization predictions with IXPE observations of radio-quiet, unobscured AGN, showing that the wedge corona can successfully reproduce the measured properties.

Speaker: Daniele Tagliacozzo (Università degli Studi Roma Tre)

15:45 Coffee break

S2 - Relativistic Jets and Particle Acceleration: Investigating the launching, collimation, and energetic processes within relativistic jets, including their composition and impact

Convener: Alessandra Lamastra (Istituto Nazionale di Astrofisica (INAF))

21 (Highlight) The Accretion-Ejection Mechanism in Low-Power Radio AGN

Low-power radio active galactic nuclei (AGN), with radio luminosities below 10$^{23}$ W Hz$^{-1}$, represent a numerically dominant yet poorly understood population, that is crucial for unveiling the full impact of radio-mode feedback on galaxy evolution. Unlike classical FRI/II sources, these faint AGN typically exhibit compact radio structures and often lack prominent extended jets or lobes, which rendered them elusive in previous radio surveys. This absence of large-scale structure, combined with their inherent radio weakness, raises fundamental questions regarding their duty cycles, their connection to host galaxy properties, and their efficiency in regulating star formation via small-scale energy injection.

The advent of high-sensitivity, multi-band surveys has significantly advanced our understanding of the nature of low-power radio AGN. These data are shedding light on the underlying accretion and ejection physics, as well as the relationship between black hole activity and host/environmental properties when compared to more powerful radio-loud AGN. In the near future, the Square Kilometre Array (SKA), with its unprecedented sensitivity and angular resolution, will definitively determine whether these low-power sources represent a distinct evolutionary stage or a fundamentally different mode of black hole accretion-ejection within the broader radio AGN population.

Speaker: Ranieri Diego Baldi (Istituto Nazionale di Astrofisica (INAF))

22 The life cycle of relativistic jets: low-power radio sources in the spotlight

Compact symmetric objects (CSOs) are intrinsically compact extragalactic radio sources and are thought to represent the progenitors of classical radio galaxies. Several evolutionary models of the radio emission have been developed so far, but they mainly focus on the evolution of high-power jets. Weak jets are more prone to instabilities than their high-power counterparts, and jet-medium interaction may decelerate or even disrupt the jet, preventing the formation of large scale structures. As a consequence, a large fraction of the energy of low-power jets is deposited in the host galaxy, and potentially impact the distribution and kinematics of the ISM of the host galaxy for longer time than high-power jets. In this contribution, we present results on VLBI observations of sample of low-power CSOs from the FIRST. Their physical properties are compared with those from high-power CSOs, in order to investigate various evolutionary paths and the influence of the environment as a function of radio power. Then we will discuss the observational limitations in determining recurrent jet activity in CSOs and how forthcoming multi-band facilities will circumvent these issues.

Speaker: Monica Orienti (Istituto Nazionale di Astrofisica (INAF))

23 From compact to giant: the lives of radio AGN on the smallest and largest scales

Understanding the life cycle of radio emission in active galaxies remains a central challenge in extragalactic astrophysics. In our study, we aim to bridge the compact and giant phases of radio galaxy evolution by investigating the incidence of remnant and restarting activity across different evolutionary stages. In this talk, I will first focus on the first evolutionary stages and present a comprehensive multi-frequency spectral study of Compact Steep Spectrum (CSS) sources from the B3–VLA sample, combining new and archival observations from the Very Long Baseline Array (VLBA) and the Very Large Array (VLA). I will then move to the giant phase, reporting a spectral ageing analysis of three Giant Radio Galaxies (GRGs) in the COSMOS field using MeerKAT UHF- and L-band observations from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey. Overall, these results provide new constraints on the duty cycle of radio-loud AGN and offer insights into the physical processes driving the growth, ageing, and recurrent activity of radio galaxies across cosmic time.

Speaker: Kathleen Kelly Lindiwe Charlton (Istituto Nazionale di Astrofisica (INAF))

S9 - Current and Future Facilities for AGN Science: Discussing the implementation and scientific exploitation of major current and future space-based and ground-based facilities with Italian involvement, focusing on maximizing their impact on AGN studies

Convener: Alessandra Lamastra (Istituto Nazionale di Astrofisica (INAF))

24 (Highlight) Millimeter and Infrared Probes of Active Galactic Nuclei: From ALMA to the Future Infrared mission PRIMA

Active Galactic Nuclei (AGN) are key probes for understanding the growth of supermassive black holes and their interplay with galaxy evolution. In the coming decades, the synergy between current and future observational facilities will significantly advance our ability to detect and characterize AGN across cosmic time.

In this context, particular emphasis is placed on the scientific exploitation of millimeter and infrared observations, which are crucial for probing obscured accretion and disentangling the different components contributing to the spectral energy distribution (SED), namely accretion-powered emission and the emission associated with star formation in the host galaxy.

This talk will focus in particular on recent results obtained with the Atacama Large Millimeter/submillimeter Array, as well as on the expected scientific advances from future facilities, including the ALMA2040 upgrade and the infrared space mission PRIMA.

Speaker: Francesca Pozzi (University of Bologna)

Social events: Brindisi city tour & Football match

25 Brindisi City Tour - Departing from Palazzo Nervegna (Italian & English)

26 Football match

Tuesday 16 June

S7 - The Early Growth of Supermassive Black Holes: Examining the formation, growth rates, and census of SMBHs in the high-redshift universe (z>6) and their role in cosmic reionization

Convener: Dr Fabrizio Fiore (Istituto Nazionale di Astrofisica (INAF))

27 (Review) The Formation and Early Growth of Supermassive Black Holes

The origin of the supermassive black holes at the centres of most galaxies has
been an open problem for decades, a mystery made even deeper by the discovery
that many were already in place at the epoch of reionization. The picture has
become increasingly intriguing with the identification of an even larger
population of accreting black holes by JWST in the early universe, which exhibit properties markedly different from AGN at later epochs or from more luminous quasars. These discoveries have challenged standard scenarios for the formation and growth of black holes in the early universe and have motivated the development of new paradigms.
In this review, I will summarize the observational properties of the diverse
population of black holes discovered in the early universe and discuss some of the scenarios proposed to explain their formation and growth. I will also
highlight the key open questions in this field and outline how they may be
addressed by future studies and upcoming facilities.

Speaker: Roberto Maiolino (University of Cambridge)

S2 - Relativistic Jets and Particle Acceleration: Investigating the launching, collimation, and energetic processes within relativistic jets, including their composition and impact

Convener: Dr Fabrizio Fiore (Istituto Nazionale di Astrofisica (INAF))

28 (Review) Dynamics, dissipation and emission of relativistic jets: new observational clues and theoretical scenarios.

In recent years our comprehension of the physical processes shaping the dynamics of relativistic jets and their emission has been revitalized by advances in both observational and theoretical tools. On the observational side, new radio and high-energy data, together with measurement of the polarization in the X-ray band by IXPE, provide a growing (albeit not undisputed) support to the scenario based on shocks as the main sites for particle acceleration. Advanced numerical simulations allow us to better describe jet production, acceleration and propagation, including the effects on the environment. On the small scale, detailed simulations probe the microphysics of particle acceleration with unprecedented detail. In the talk I will review some of these progresses, also mentioning the potential multi messenger role of jets from AGNs.

Speaker: Fabrizio Tavecchio (Istituto Nazionale di Astrofisica (INAF))

29 A detailed study of the radio-gamma connection in a large sample of 4LAC AGNs

Speaker: Alessandro Paggi

30 Tracing the end of AGN jets: the first large sample of remnant radio galaxies

The active phase of jetted AGN can last several tens or hundreds of Myr, after which the radio jets cease and the source begins to fade. This so-called remnant plasma provides a unique opportunity to constrain jet activity timescales - a key parameter in feedback models - and to study the long-term impact of AGN on their surrounding environment. Historically elusive, these sources are now being revealed in larger numbers by low-frequency surveys with SKA precursors and pathfinders. Despite this progress, systematic selection remains challenging.

In this talk, I will present recent advances in the field, focusing on our new systematic search for remnant radio galaxies in the LoTSS HETDEX field at 150 MHz. Using a semi-automatic approach, we have identified the largest sample to date, with over 100 candidate sources. I will discuss the methods and challenges involved in identifying these complex objects and how this sample can be leveraged to train machine learning algorithms to expand the search. Finally, I will show how the observed properties of this sample can be interpreted within the framework of radio galaxy population models and hydrodynamical simulations. This study lays the groundwork for the first statistical investigation of remnant radio galaxies and highlights the discovery potential of future SKA surveys.

Speaker: Marisa Brienza (Istituto Nazionale di Astrofisica (INAF))

11:00 Coffee break

S2 - Relativistic Jets and Particle Acceleration: Investigating the launching, collimation, and energetic processes within relativistic jets, including their composition and impact

Convener: Dr Fabrizio Fiore (Istituto Nazionale di Astrofisica (INAF))

31 Modeling of multi-zone Synchrotron polarization of blazars: insights from new data and connection to particle acceleration

I will show that current mm-to-X-ray polarization trends observed during recent IXPE campaigns for high-synchrotron peaked blazars and the ROBOPOL optical envelope observed for Fermi blazars, which relate the fractional polarization to the peak frequency of the synchrotron emission, can be fully accounted for by a purely turbulent, multi-zone model, without requiring correlations between the cell size and the EED parameters. The polarization degree is primarily governed by the effective number of flux-weighted emitting cells, which depends sensitively on the dispersion of cell properties—especially the EED cutoff energy at high frequencies and the low-energy spectral index at low frequencies. I will also discuss some implications of the statistical properties of the polarization on the underlying acceleration processes, and I will present preliminary results from a turbulent multi-zone model within a conical jet with an underlying ordered magnetic field.

Speaker: Andrea Tramacere

32 Unveiling the Physics of Blazar Emission Through Quasi-Periodic Oscillations Studies

Speaker: Alba Rico

33 A FLASH on Blazars: mapping relativistic jets from MHz radio to GeV gamma rays with SKA pathfinders

Speaker: Meriem Behiri

S3 - Black Holes Across the Mass Scale and Time-Domain Probes: Exploring the accretion and ejection coupling through analogies and differences between supermassive black holes (SMBHs), intermediate and stellar-mass compact objects and through transient sources

Convener: Dr Fabrizio Fiore (Istituto Nazionale di Astrofisica (INAF))

34 (Review) Accretion and jets in X-ray binaries

The inflow of matter onto astronomical objects is connected to the generation of outflows throughout the Universe on a variety of scales, from proto-planetary disks, to merging neutron star systems and gamma ray bursts, to stellar mass and supermassive black holes.

The matter inflow/outflow processes scale predictably with mass, and proceeds according to the same basic principles around all collapsed objects, slower around supermassive black holes and much faster near stellar mass compact objects.
Low-mass X-ray binaries hosting either stellar mass black holes or neutron stars are the most common type of transient in the Galaxy, and constitute ideal laboratories where to study the accretion/jet connection at work in real time.
I will focus on black hole X-ray binaries, and I will give an overview on accretion states and how they are associated with jets. I will review some of the most important science that has been done recently, especially with the MeerKAT telescope, precursor of the SKA.

Speaker: Sara Elisa Motta (Istituto Nazionale di Astrofisica (INAF))

35 Asimmetrie invisibili. Divari economici, soffitto di cristallo e violenza economica

Speaker: Annarita Del Vecchio (Psicologa di Comunità | Project Manager)

13:05 Lunch break (lunch is not provided as part of the event)

S3 - Black Holes Across the Mass Scale and Time-Domain Probes: Exploring the accretion and ejection coupling through analogies and differences between supermassive black holes (SMBHs), intermediate and stellar-mass compact objects and through transient sources

Convener: Angela Malizia (Istituto Nazionale di Astrofisica (INAF))

36 Transient Probes of Intermediate-Mass Black Holes in the MORFEO era: TDEs and QPEs

Speaker: Elisa Bortolas

37 A fundamental plane of black hole accretion in the millimetre

The last three decades of observations have demonstrated that the mass of central super-massive black holes (SMBHs) correlates with a number of properties of their host galaxies, suggesting a connection between the growth of these massive compact objects and their host galaxy evolution (so-called "co-evolution”). Galaxy formation theories, however, still struggle to shed light on the physical processes driving and regulating such co-evolution. Understanding the nature of accretion onto SMBHs, as well as setting accurate constraints on fundamental properties such as their mass, is crucial in this regard.
In this talk, I will present the recent discovery of a tight correlation between the nuclear ALMA 1mm luminosities, SMBH masses, and 2-10 keV X-ray luminosities that is found to hold for both low-luminosity active galactic nuclei (LLAGN) and high-luminosity (quasar-like) AGN. This has been dubbed as the ``millimetre fundamental plane of BH accretion”. Crucially - for all AGN types - spectral energy distribution (SED) models for advection-dominated accretion flows (ADAFs) naturally explain the existence of the relation, which is instead not reproduced by standard torus-thin accretion disc models usually associated to high-luminosity AGN. I will discuss the implications of this discovery for our understanding of BH accretion in different AGN types, as well as its great potential as rapid method to (indirectly) estimate SMBH masses.

Speaker: Dr Ilaria Ruffa (INAF - OAA)

38 Rising Tides in Active Galaxies: Nuclear Transients and Episodic Activity in NGC 7213, AT2021hdr, and SDSS J1335+0728

Recent time-domain surveys are revealing a growing population of nuclear transients that trace rapid changes in the accretion state of supermassive black holes. These events offer a unique opportunity to study how previously quiescent or weakly active nuclei transition into phases of enhanced accretion and variability. In this contribution I will present recent multiwavelength results on a small sample of nearby galaxies that display different manifestations of such nuclear activity.

In the nearby LINER galaxy NGC 7213, new radio observations reveal evidence for a weak jet and compact hotspots associated with a previous episode of nuclear activity, suggesting recurrent jet launching on galactic scales. In the nuclear transient AT2021hdr, optical monitoring uncovered oscillations in the light curve with characteristic timescales of ∼60–90 days, accompanied by correlated variability in the UV and X-ray bands. This unusual behaviour challenges standard interpretations in terms of tidal disruption events or classical AGN variability and may instead point to the tidal disruption of a gas cloud in a binary supermassive black hole system.

Another remarkable case is the galaxy SDSS J1335+0728, which showed no detectable nuclear variability for decades before entering a new active phase in 2019. Multiwavelength observations reveal a rapidly evolving UV/optical and mid-infrared emission together with the recent appearance of soft X-ray radiation, suggesting that the central black hole may be in the process of turning on as an AGN. Follow-up observations have also revealed the presence of X-ray quasi-periodic eruptions (QPEs) in this source, placing it among the rare systems where extreme nuclear variability can be studied in real time.

Together, these objects illustrate the rich phenomenology of nuclear transients and highlight how time-domain surveys are uncovering a dynamic population of galaxies in which supermassive black holes intermittently switch between quiescent and active states. Studying these systems provides new insight into the physical mechanisms governing accretion instabilities, episodic jet activity, and the onset of AGN phases. In the coming years, facilities such as the Vera C. Rubin Observatory (LSST) and the Square Kilometre Array (SKA) will dramatically expand the discovery space of nuclear transients, enabling systematic studies of the onset and evolution of accretion and jet activity in galactic nuclei.

Speaker: Dr Gabriele Bruni (INAF - Istituto di Astrofisica e Planetologia Spaziali)

Rising_Tides.pdf

39 Feeding a Black Hole with a star: Tidal Disruption Events in the Time Domain Astronomy Golden Age

When an unfortunate star wanders too close to a Super Massive Black Hole (SMBH) it can be destroyed by the strong tidal forces at play. These Tidal Disruption Events (TDE) are powerful transient sources which reveal the presence of dormant SMBHs in the low-mass regime. Thus, they represent an extraordinary laboratory for studying the properties of a population of SMBHs complementary to the AGN-selected one and accretion-related phenomena occurring on human-friendly time-scales.
TDEs are exquisite multimessenger transients, being bright in different bands (from X-rays to radio), candidates sources of high-energy neutrinos and gravitational wave sources potentially detectable by future space-based interferometers (such as LISA and LGWA).
In the last decade, thanks to the development of powerful wide-field surveys dedicated to the search of transients, the TDEs detection rate has quickly grown from few candidates serendipitously discovered to 10 TDE/yr, revealing an intriguing and puzzling diversity in the observational properties. Despite the impressive progress in this field, there are many aspects that remain unclear, such as the emission mechanism behind all the observed features and the geometry of the emitting region.
The start of the Rubin Observatory's Legacy Survey of Space and Time (LSST) survey operations will bring the TDE science to a new and unprecedented era, with an expected impressive discovery rate of 10 TDE/day and the possibility of detect the fast and faint ones, which could involve IMBHs. In this talk I will present the recent achievements in the TDE science, obtained thanks the progress in the candidates selection and classification process and the follow-up strategies. I will show some recent peculiar cases which are interesting in the framework of interesting candidates selection, TDE rate and hosting environments. Finally, the LSST impact will be also discussed.

Speaker: Francesca Onori (Istituto Nazionale di Astrofisica (INAF))

40 HLX-1: a TDE on an Intermediate-Mass Black Hole?

Intermediate-mass black holes (IMBHs) constitute the missing link between stellar-mass and supermassive black holes (BHs). As such, they are crucial to trace BH growth and its connection with galaxy evolution. However, their presence in the local universe remains elusive: less than a dozen X-ray-bright IMBH candidates have been found so far. Among these, ESO243-49 HLX-1 stands out as one of the most convincing and represents the perfect benchmark to analyse properties, behaviours and host environments of this population.

Located close to the outskirts of the spheroidal galaxy ESO243-49, this variable X-ray source exhibited a total of eight recurrent outbursts between 2008 and 2017 and has since settled in a Low/Hard state. The nature of these outbursts and its optical counterpart, detected from the NIR to the far-UV bands, have long been subject of debate.

In this talk I will present new results from the most recent analysis of HLX-1's optical/UV and X-ray evolution using archival HST, Chandra, and Swift data. The connection between the optical and X-ray emission confirms the constant red component as a host globular cluster or UCD. More importantly, the data challenge the irradiated disk interpretation of the slowly declining blue component, favouring instead emission from an outflow photosphere similar to those seen in tidal disruption events (TDEs). This may also explain the origin of the X-ray oscillations as an inner disk instability in the early years after the TDE. Finally, I will show that our observations resolve a mysterious far-UV source near HLX-1 into a ring-like star-forming structure, and explore the possibility of a physical association with HLX-1 and its host cluster.

Speaker: Ms Maya Garbaccio Gili (Istituto Nazionale di Astrofisica (INAF))

S3 - Black Holes Across the Mass Scale and Time-Domain Probes: Exploring the accretion and ejection coupling through analogies and differences between supermassive black holes (SMBHs), intermediate and stellar-mass compact objects and through transient sources

Convener: Angela Malizia (Istituto Nazionale di Astrofisica (INAF))

41 The Timedomes project: probing AGN populations through legacy optical monitoring campaigns.

The combination of past and new monitoring optical surveys is allowing to probe the intrinsic properties of accreting supermassive black holes through variability studies. I will present results of the Timedomes campaign to target the LSST Deep Drilling Fields in order to assemble a legacy dataset of AGN lightcurves going back more than 10 years down to magnitude limits comparable with LSST single-epoch observations. I will discuss the results in the context of recent efforts to constrain the long-term variability of AGN as a tool to provide constrains ranging from the unification model, to AGN demographics and cosmology. I will finally show how the inclusion of the first LSST Data may improve the results and allows to forecast the potential of the full survey.

Speaker: Maurizio Paolillo (Università di Napoli Federico II)

16:05 Coffee break

S4 - Binary and Dual AGN Systems: Studying the observational signatures, dynamics, and gravitational wave implications of closely separated and merging black hole systems

Convener: Angela Malizia (Istituto Nazionale di Astrofisica (INAF))

42 (Review) Dual and Binary AGN: observational signatures and connections to Gravitational-Waves

Binary and dual massive black holes (MBHs) are a natural outcome of galaxy mergers. Systems in which both black holes are active (dual and binary active galactic nuclei, AGN) provide a unique opportunity to study the dynamical evolution of merging galaxies, the triggering of accretion, and the processes that lead to the formation of gravitational-wave (GW) emitting MBH binaries.
In this talk I will summarise the current observational status of dual and binary AGN across a wide range of spatial scales, from kpc-scale dual systems to pc-scale binaries. I will discuss the main observational techniques used to identify candidates, including high-resolution imaging and spectroscopy, radio interferometry, and time-domain variability analyses, highlighting the strengths and limitations of each method.
I will outline the prospects for future discoveries with upcoming time-domain surveys and high-resolution facilities, and I will discuss the implications of binary AGN studies for current and future low-frequency GW experiments, such as PTAs, LISA, and LGWA.

Speaker: Paola Severgnini (Istituto Nazionale di Astrofisica (INAF))

43 Multiple AGN systems at z ~ 3 revealed by JWST/NIRSpec IFU

Dual and multiple AGN provide a unique window into black-hole growth, galaxy interactions, and feedback in dense environments, yet they remain poorly constrained at high redshift. I will present JWST/NIRSpec IFU observations of GS10578, a massive quenched galaxy at z=3.06 hosting an X-ray AGN that drives multiphase outflows, with a close secondary AGN at a projected separation of 5 kpc. Exploiting rest-frame optical diagnostics enabled by new JWST observations, we investigate the nature of two Lyα emitters located in the environment of GS10578 and previously discovered with VLT/MUSE data. One of them, LAE2, lies at a projected distance of 28 kpc from GS10578, and had been proposed as a third AGN based on UV line diagnostics. Our NIRSpec observations reveal rest-frame optical line ratios fully consistent with AGN photoionisation, confirming that LAE2 hosts an accreting SMBH. In contrast, a second Lyα source (LAE1) remains undetected in all rest-frame optical lines and continuum emission, even in deep JWST/NIRCam and MIRI imaging. Its broad and asymmetric Lyα profile suggests resonantly scattered emission powered by LAE2 rather than in-situ star formation. Together, these results reveal a complex, multi-scale AGN environment around a quenched massive galaxy at z∼3, hosting three accreting SMBHs across separations ranging from a few to ~30 kpc. In addition, I will present recent results from the GA-NIFS collaboration on dual and multiple AGN systems uncovered with JWST, highlighting how NIRSpec IFU is transforming our view of black-hole growth and galaxy interactions in the early Universe.

Speaker: Dr Michele Perna (Centro de Astrobiología (CAB), INTA-CSIC)

44 Dual AGN and where to find them

Dual AGN at kpc-scale separations (<7 kpc) within the same galaxy trace a key phase of galaxy mergers, when gas fuels both star formation and supermassive black hole (SMBH) growth. At z > 0.5, near the peak of star formation and AGN activity, these systems provide a direct view of this critical stage of galaxy evolution.
Despite their importance, only a limited number of sub-arcsecond (0.7”~7 kpc at z = 0.5–2) dual AGN at z>0.5 were previously known. Using the Gaia Multi-Peak (GMP) method, we have now identified a sample of ~35 candidate systems at sub-arcsecond scales, representing a significant increase in the known population.
However, their cold molecular gas content remains largely unexplored: the few targets observed so far are mostly confined to the local Universe, with only one system at z>1 (Ishikawa+25). I will present ongoing ALMA observations of a sub-sample of confirmed dual AGN, probing their cold molecular gas reservoirs. All confirmed systems have measured SMBH masses, and we report evidence for an ionized gas outflow in one system. These observations provide first constraints on the gas content of these systems and on the role of AGN feedback in the phase preceding SMBH coalescence.

Speaker: Dr Maria Vittoria Zanchettin (Istituto Nazionale di Astrofisica (INAF))

45 Black Hole Growth in the Densest Regions of the Universe: AGN activity in protoclusters from Cosmic dawn to the present days

Recent observations suggest that active galactic nucleus (AGN) activity is enhanced in overdense environments, such as galaxy protoclusters, compared to the field. However, these results are based on limited observational samples and heterogeneous selections of AGN and host galaxies, making it difficult to identify the physical origin of this apparent enhancement and to disentangle genuine environmental effects from selection-driven biases.
Cosmological simulations provide a powerful avenue to overcome these limitations, as their large volumes enable the systematic study of hundreds of galaxy clusters and their progenitors across cosmic time. In this talk, I will present the first statistical analysis of the demography and evolution of supermassive black holes (SMBHs) in galaxy protoclusters from the cosmic dawn to the present day, based on the IllustrisTNG simulation suite.
I will show that, at fixed host-galaxy stellar mass, the AGN fraction in protoclusters is comparable to that in the field, indicating that overdense environments do not significantly enhance black hole accretion through direct environmental triggering. Nevertheless, an apparent enhancement of the AGN fraction as a function of redshift emerges when integrating over the evolving galaxy population. We demonstrate that this effect is driven primarily by differences in the stellar-mass distributions of galaxies in overdense regions, which host massive galaxies and actively accreting SMBHs earlier than the field. This interpretation is further supported by the analysis of the AGN bolometric luminosity function and the cosmic black hole accretion rate density, which reveal a dominant contribution from protoclusters at high redshift. Finally, I will discuss the comparison between simulation predictions and current observational constraints, and the implications for interpreting AGN activity in dense environments.

Speaker: Alberto Traina (Istituto Nazionale di Astrofisica (INAF))

Social events: Public Lecture (Palazzo Nervegna) - Prof. Roberto Maiolino "La nascita e l'evoluzione di stelle, galassie e buchi neri attraverso le epoche cosmiche”

Wednesday 17 June

S4 - Binary and Dual AGN Systems: Studying the observational signatures, dynamics, and gravitational wave implications of closely separated and merging black hole systems

Convener: Viola Allevato (Istituto Nazionale di Astrofisica (INAF))

46 (Highlight) Gravitational Waves from the Cosmic Dawn: Tracing Cosmic Black Hole Binaries with ET, LGWA and LISA

Speaker: Rosa Valiante

47 Dual AGN at Cosmic Noon: Bridging Observations and Theory with the First Statistical Sample

A large population of AGN pairs residing in the same galaxy, the so-called dual AGN, is predicted to exist at redshifts z>0.5. These systems constitute the parent population of merging black holes (BHs), making their number and properties a key ingredient for theoretical predictions of the gravitational-wave (GW) background and event rates probed by pulsar timing array (PTA) experiments and by the future Laser Interferometer Space Antenna mission (LISA).
Until recently, only a handful of dual AGN had been identified at sub-arcsecond separations. In this talk, I will present the first statistically significant sample of systems with separations ranging from 0.15″ to 0.8″ (∼kpc at z>0.5) selected using the innovative Gaia multi-peak (GMP) technique based on data from Gaia. We observed approximately one hundred systems at cosmic noon to confirm their nature and distinguish true dual AGN from gravitationally lensed systems using spatially resolved spectroscopy obtained with several ground-based AO-assisted facilities, including Keck Observatory and Very Large Telescope.
Building on the classification of these systems, I will present the first comprehensive study of dual AGN properties, including bolometric luminosities, Eddington ratios, black hole masses, mass ratios of the pairs, their fraction within the overall AGN population, and how these quantities evolve with redshift, magnitude, and separation.
For the first time, we perform a statistical comparison between a sample of ∼50 confirmed dual AGN and theoretical predictions from cosmological simulations and analytical models, including L-GALAXIES and ASTRID. These results provide the first observational constraints on the population of dual AGN at cosmic noon and enable a direct link between observations and theoretical predictions of black hole growth during galaxy mergers. In particular, the inferred distributions of dual AGN properties allow us to place new constraints on the expected rate of massive black hole mergers and to predict the population of GW events that will be detectable by LISA.

Speaker: Martina Scialpi (Università di Firenze, Università di Trento, INAF/OAA)

48 MBH pairs below 100 pc (and more?): toward robust detection strategies

Speaker: Fabio Rigamonti

49 Did We Just Confirm a Gravitational Wave Recoiling Black Hole in 3C 186?

Speaker: Marco Chiaberge

50 The role of major mergers in triggering super-Eddington accretion

JWST observations have opened a new window on the early Universe, revealing black holes with masses of several million solar masses already at z>8, which challenge our understanding of their accretion mechanisms. In recent years, super-Eddington accretion has emerged as a promising solution and has been adopted in both simulations and semi-analytical models.

In this talk, I will present the results of my recent work investigating the role of super-Eddington accretion in cosmological hydrodynamical zoom-in simulations during a major merger between two haloes at z=11. We performed a suite of runs exploring different seeding prescriptions and feedback configurations. I will show that in the majority of the runs performed, the merger has a negligible impact on black hole accretion, while accretion is primarily regulated by black hole kinetic feedback and the gas density around it.

Speaker: Riccardo Caleno (Sapienza Università di Roma)

10:50 Coffee break

Poster Session 1

Convener: Viola Allevato (Istituto Nazionale di Astrofisica (INAF))

51 AGILE: an end-to-end Rubin-LSST simulation of AGNs, galaxies, and stars

Speaker: Akke Viitanen

52 Are Little Red Dots Powered by Highly Accreting Supermassive Black Holes?

Speaker: Andrea Sacchi

53 The abundance of little red dots from cosmic dawn to noon

Speaker: Federica Loiacono

54 JWST/NIRSpec characterisation of the first highly accreting quasars and their multi-scale properties at z >6

Speaker: Blessing Musiimenta

55 Semi-empirical constraints on the high-z SMBH population and the implications for their early evolution

Speaker: Daniel Roberts

56 Euclid and the Multiwavelength View of AGN Host Galaxies: New Insights into Galaxy–AGN Co-evolution

Speaker: Antonio La Marca

57 Multi-wavelength analysis of QSO spectra with QSFit: A showcase on Euclid and DESI data

Speaker: Giorgio Calderone

58 Lines in the sky - Physical properties of QSOs from Euclid spectral fitting

Speaker: Joao Jose Feio Calhau

59 Hot Dust Across Cosmic History: Probing the Torus Evolution of Luminous Quasars with SPHEREx

Speaker: Arpita Ganguly

60 A Two-Corona Model for Two High-Luminosity Quasars: RBS 229 and PG 1407+265

Speaker: Alessandro Leonardo Lai

61 The WISSHFUL XMM Heritage Program: probing accretion and ejection in luminous QSOs at Cosmic Noon

Speaker: Giorgio Lanzuisi

62 Ultra-fast BAL outflows as tracers of AGN feedback at cosmic noon

Speaker: Giustina Vietri

63 The windy nuclear environment of a weak-line quasar at cosmic noon

Speaker: Ilaria Villani

64 A multi-scale multi-phase view on AGN feedback on the host ISM

Speaker: Francesco Salvestrini

65 Not only heating! A numerical study on how AGN kinetic jet feedback can trigger cold gas formation

Speaker: Stefano Sotira

66 A probabilistic view of the AGN-SFG population in the era of EMU and SKA

Speaker: Jahang Prathap

67 A gamma-ray study of luminosity and duration of FSRQs flares

Speaker: Luigi Pacciani

68 Blazar Monitoring and variability analysis using the Italian radio telescopes

Speaker: Rupal Giri

69 Radio Monitoring of the Nuclear Transient AT2021hdr: Evidence for a Decline in Flux Density

Speaker: Enrico Maria Tricarico

S5 - Multi-Messenger: Leveraging variability studies, gravitational waves, and high-energy neutrinos (multi-messenger astronomy) to understand the immediate vicinity of the central engine

Convener: Viola Allevato (Istituto Nazionale di Astrofisica (INAF))

70 (Review) Cosmic-Ray Acceleration and Hidden Neutrino Production in Seyfert Galaxies

Speaker: Enrico Peretti

71 A VHE gamma-ray perspective of Neutrino emitting Seyfert candidates

Seyfert galaxies have emerged as the most promising counterparts to TeV neutrino excesses detected by IceCube, with significant associations above the 3σ level. Stacked analyses of X-ray bright AGN further indicate a collective signal at ~3σ, supporting their contribution to the multi-messenger neutrino sky.
The AGN environment provides multiple sites capable of accelerating protons to the energies required to account for the observed neutrino flux. Gamma rays and neutrinos are co-produced through hadronic interactions between the accelerated protons and the ambient matter and radiation in the emission region.
However, radiation-dense regions like AGN cores efficiently absorb gamma rays, potentially suppressing part of the very-high-energy(VHE) emission(E>100 GeV). VHE gamma telescopes such as MAGIC are sensitive to an energy range similar to that of IceCube. Thus, they serve as an efficient probe to test the optical depth of these environments. VHE gamma-ray observations with the MAGIC telescopes of the most significant neutrino hotspot, NGC 1068, have already yielded stringent upper limits, revealing the presence of a gamma-ray obscured accelerator.
In this talk, we present observations of another promising neutrino counterpart, NGC 4151, and report the first upper limits on its VHE (E > 100 GeV) gamma-ray emission. The derived constraints limit the neutrino-emitting region up to ~10⁴ Schwarzschild radii of the central supermassive black hole. These results indicate that, similar to NGC 1068, NGC 4151 likely hosts a neutrino production site that is optically thick to gamma rays, supporting Seyfert galaxies as a potential class of hidden cosmic-ray accelerators.

Speaker: Sweta Menon (Istituto Nazionale di Astrofisica (INAF))

72 All they know is what they are not: the accretion of neutrino-emitting blazars

Blazars are a class of AGN characterised by relativistic jets pointed towards our LoS. Traditionally, they are classified into two families: BL Lacs (no emission lines suggesting an inefficient accretion flow and faint bluer broad band SEDs) and FSRQs (strong emission lines, radiatively efficient accretion and brighter red SEDs). However, recent studies have highlighted that blazars identified as potential neutrino emitters show unusual spectral properties which don't allow a standard classification. I will present the analysis of a spectroscopic sample of neutrino-emitter blazars. Many of these sources exhibit peculiar spectral features that have led to their interpretation as masquerading BL Lacs, i.e. blazars whose powerful jet emission hides the spectral signatures of a radiatively efficient accretion disk. To better understand their nature, we use the broad emission lines as tracer of the ionising disc luminosity, and thus constrain their accretion regime, most likely transitional between standard and inefficient. We exploit the interplay between spectroscopic analysis and broad band photometric data, comparing the results obtained from these two independent methods. This approach allows us to investigate whether these sources are intrinsically efficient accretors whose emission lines are diluted by the jet, or they represent a distinct population. Understanding their accretion properties and emission mechanisms will also provide important clues about the connection between blazars and high-energy neutrino emission, lately linked also to non-jetted AGN.

Speaker: Gaia Delucchi (Istituto Nazionale di Astrofisica (INAF))

13:00 Lunch break (lunch is not provided as part of the event)

Poster Session 2

Convener: Andrea Merloni

73 Are narrow-line and broad-line Seyfert 1s distinct X-ray populations?

Speaker: Emanuele Nardini

74 Decade-Long Variability of Soft X-ray Wind in PG 1211+143: A Comparative XMM-RGS Study

Speaker: Sreeparna Ganguly

75 The Chandra-HETG spectrum of 4U 1746-37: hints for red- and blue-shifted high-velocity FeXXV and XXVI Absorption

Speaker: Federico Di Salvo

76 Time-evolving density and temperature line diagnostic for high-resolution X-ray spectroscopy

Speaker: Francesca Diaferia

77 X-ray disc reverberation modelling of the X-ray/UV/optical spectral/timing properties of Fairall 9

Speaker: Michalis Polioudakis

78 X-ray Obscuration vs molecular gas distribution in local AGN

Speaker: Manuela Molina

79 Photoionisation by Non-thermal Continuum as the reason for LINER Spectra in LLAGN

Speaker: Nischal Acharya

80 Investigating AGN feedback in FR0 radio galaxies

Speaker: Fabrizio Gandossi

81 Unveiling dual AGN in advanced galaxy mergers with MUSE-IFU

Speaker: Manali Parvatikar

82 Nuclear and galactic ionized winds in a quiescent massive galaxy KUG 1208+386 hosting an obscured AGN

Speaker: Yerong Xu

S6 - AGN Feedback and the Host Galaxy: Analyzing how AGN energy output (kinetic and radiative feedback) impacts star formation and gas distribution within the host galaxy and its surrounding dark matter halo

Convener: Andrea Merloni

83 (Review) Exploring the impact of (radio) AGN on galactic scales by tracing different phases of the gas

A variety of results obtained in the recent years are suggesting that not only the presence of gas outflows is a signature of the impact of the energy released by the active SMBH, but also the physical conditions of the gas in the central (kpc-scales) regions of galaxies can be used to trace such impact.
These effects have been seen in gas observed around both high and low luminosity AGN.
In this talk I will summarise some of the results obtained for a range of phases of the gas, from hot gas traced by X-ray observations to warm and cold molecular gas. The results from ALMA/NOEMA and, more recently, JWST are expanded this field as we speak!
I will focus in particular on the impact of (young) radio jets: while expanding in the ISM they can create a cocoon of shocked gas which can explain e.g. the extreme line ratios seen in the cold molecular gas, shocked gas at the origin of LINERs spectra, outflows and extended X-ray emission in the direction perpendicular to the jets. These are all elements that can have a relevance for connecting the impact of the AGN to the properties of the ISM in the host galaxy.
If time allows, I will present the case of 3C84 (NGC1275) as an example of connecting and closing the feeding and feedback loop, while helping building a circumnuclear stellar disc.

Speaker: Raffaella Morganti (ASTRON/Kapteyn Institute)

15:30 Coffee break

S6 - AGN Feedback and the Host Galaxy: Analyzing how AGN energy output (kinetic and radiative feedback) impacts star formation and gas distribution within the host galaxy and its surrounding dark matter halo

Convener: Andrea Merloni

84 (Highlight) The physical properties, acceleration mechanism and impact of AGN outflows from low to high redshift

Feedback from AGN is considered the main physical mechanism to quench star formation in galaxies, at least at the high mass end of the galaxy population. This feedback is believed to operate through powerful, massive outflows driven by the energy release operated by the AGN.
However, while outflows are ubiquitous in AGN, their origin, properties and impact on host galaxies and physical properties are still poorly known.

I will present the results from several observational programs
targeting AGN host galaxies from low to high redshift and aimed at overcoming these limitations using integral field spectroscopy, showing the effects of AGN winds host galaxies and insights on the properties and acceleration mechanisms  of these winds.

Speaker: Giovanni Cresci (Istituto Nazionale di Astrofisica (INAF))

85 Unveiling the driving mechanism of AGN-driven outflows: a multi-wavelength perspective

AGN-driven multiphase outflows are thought to play a fundamental role in regulating both star formation and matter accretion onto supermassive black holes. However, the physical mechanisms driving their acceleration, as well as their energetic budget, remain poorly constrained by existing kinematic models, leaving their true impact on galaxy evolution uncertain. I will present a comprehensive 3D kinematic and morphological analysis of outflows in a statistical sample of eleven nearby AGN exploiting innovative modelling tool. Our results reveal, for the first time, compelling evidence for a two-stage kinematic regime: an inner zone characterized by nearly constant outflow velocity, followed by a phase of rapid acceleration on larger scales. I will show how this behaviour closely matches state-of-the-art theoretical predictions for pure adiabatic AGN-driven winds, enabling us to derive unprecedented estimates of the outflow energetics and their coupling with the host galaxy. I will present observational evidence that these outflows efficiently entrain substantial amounts of gas and are capable of removing it from the galaxy’s gravitational potential, effectively clearing the interstellar medium along their path. These findings provide key insights into the physical origin of AGN winds, the mechanisms powering them, and the way energy and momentum are transferred to the surrounding medium. Our conclusions are supported by archival MUSE data and new JWST/MIRI observations, which together offer a transformative view of the role of AGN feedback in shaping the galaxy evolution.

Speaker: Dr Cosimo Marconcini (Istituto Nazionale di Astrofisica (INAF))

86 Disrupting the ISM: How AGN Feedback Reshapes Molecular Gas Clumpiness

The central kiloparsec of AGN host galaxies is a critical site where accretion, feedback, and galaxy-scale evolution intersect. Among the key components regulating this interplay is the dense molecular gas, which fuels both star formation and AGN activity, and constitutes the bulk of gaseous mass within the central region. In this study, we investigate how AGN feedback affects the morphology and clumpiness of molecular gas within the inner ~100 pc of local Seyfert galaxies. Using sub-arcsecond (~10 pc) ALMA observations of CO(3-2) emission from the GATOS (Galactic Activity, Torus, and Outflow Survey) sample, we analyze the spatial distribution of molecular gas and its connection to AGN luminosity and Eddington ratio. To quantify gas clumpiness, we apply a modified non-parametric structural analysis based on the CAS (Concentration, Asymmetry, Smoothness) method, adapted for molecular line emission. We find a systematic decrease in molecular gas clumpiness with increasing AGN luminosity, with a significant transition at X-ray luminosities of $L_X \sim 10^{41}-10^{42}$ erg/s. This trend suggests that AGN-driven feedback processes, likely outflows and turbulence induced by the AGN engine, disrupt the formation of large dense gas clouds in the nuclear and circumnuclear region. Our results provide direct observational evidence that AGN feedback reshapes the molecular ISM structure on tens-of-parsec scales, potentially suppressing star formation and altering the conditions of the accreting gas. These findings provide a new perspective on how AGN feedback regulates the cold gas reservoir of galaxies, thereby impacting their evolution.

Speaker: Federico Esposito (Observatorio Astronómico Nacional (OAN-IGN, Madrid))

87 Unveiling the role of multi-phase AGN outflows with MIRACLE

Galaxy evolution is tightly connected to Active Galactic Nuclei (AGN), through feedback processes in which gas accretion onto the supermassive black hole drives powerful multiphase outflows. Detailed studies in the local Universe are crucial to resolve the physical scales and gas phases involved, enabling a comprehensive view of AGN-host interactions.
I will present first results from the MIRACLE (Mid-IR Activity of Circumnuclear Line Emission) program, combining JWST/MIRI, MUSE, and ALMA observations of seven nearby Seyfert galaxies. Thanks to JWST’s spatial resolution (50-150 pc), we probe atomic and molecular gas in the dusty circumnuclear regions of these sources, and assess the impact of AGN activity on their host galaxies.
Focusing on NGC 1365, we trace the ionized outflow up to kiloparsec scales and constrain its energetics and effects on star formation (SF). By combining mid-IR diagnostics with advanced photoionization and kinematic models, we reproduce ~60 optical and mid-IR emission lines, disentangling AGN- and SF-driven components and providing robust estimates of gas density, ionization, extinction, and outflow mass. Our results demonstrate that classical methods, which rely on strong assumptions about ionization state, average density, and extinction correction, can underestimate the outflow mass by up to an order of magnitude. This marks the first time such a detailed, physically grounded approach has been applied to spatially resolved AGN-driven outflows, providing a new benchmark for future studies.

Speaker: Matteo Ceci (Università di Firenze)

Social events

88 Meet at Autorità Portuale to get to Castello Alfonsino

89 Visit to Castello Alfonsino

90 Social Dinner at "Al Porticciolo" Restaurant

91 Bus back to Autorità Portuale

Thursday 18 June

S6 - AGN Feedback and the Host Galaxy: Analyzing how AGN energy output (kinetic and radiative feedback) impacts star formation and gas distribution within the host galaxy and its surrounding dark matter halo

Convener: Guido Risaliti (Università di Firenze. Dipartimento di fisica e astronomia)

92 (Review) Probing the link between dense environment and SMBH growth at high redshift

The large-scale environment is among the key factors that shape galaxy evolution, but, crucially, its impact on the cosmic growth and evolution of SMBHs is still poorly probed. Galaxy clusters in the local Universe host populations of galaxies and SMBHs that are typically more massive and evolved than in the field environment. Therefore, their high-redshift (z>2) progenitors are the best laboratories to study the environmental effects on galaxy and SMBH growth. I will review our current understanding of how the environment influences SMBH growth by focusing on studies of z>2 protoclusters that aim to probe the incidence and properties of the AGN in such structures, using both observational and theoretical approaches. Then, I will review the few examples of ongoing AGN feedback on the surrounding environment in dense regions of the high-redshift Universe, whose effect is expected to concur in shaping the observational properties of local clusters. Finally, I will discuss briefly the role that state-of-the-art and future facilities will play to improve our knowledge of the link between dense environment and SMBH evolution at high redshift.

Speaker: Fabio Vito (Istituto Nazionale di Astrofisica (INAF))

93 An HIPER view of AGN feedback on the gas reservoirs at cosmic noon

Active galactic nuclei (AGN) are thought to play a key role in shaping the buildup of galaxies. AGN-driven outflows could be responsible for efficient gas removal or heating and are now routinely detected at any redshift. At the same time, if AGN influence galaxy growth, then they will reasonably impact the molecular gas reservoir first, and star formation as a consequence. While convincing evidence that AGN hosts at cosmic noon (z~1-3) harbor reduced amounts of molecular gas mass compared to their non-AGN analogs is growing, we still have to pinpoint how such a reduction is set into place. The ERIS GTO program HIPER (High resolution Investigation of Feedback Processes with ERis; PI: G. Cresci) specifically aims at probing whether the level of molecular gas depletion is related to the properties, such as strength and velocity, of AGN-driven winds.
I will present our most recent efforts in investigating causes and effects of AGN feedback on galaxies at cosmic noon, from gas depletion in AGN hosts to the properties of AGN-driven outflows as traced with new-generation instruments as JWST/NIRspec and VLT/ERIS.

Speaker: Elena Bertola (Istituto Nazionale di Astrofisica (INAF))

94 Gentle but Persistent: Shock-Driven Feedback in Low-Accreting Black Holes

Supermassive black holes spend up to 95% of their lifetimes in low-accretion states, yet the nature and cumulative impact of their feedback remain poorly constrained. Recent JWST observations of M58, a nearby low-luminosity AGN (LLAGN), reveal more than 44 molecular hydrogen emission lines excited by low-velocity, low-density shocks. The shocked warm molecular gas extends to kiloparsec scales without exhibiting strong large-scale kinematic disturbances. However, within the central ~200 pc, the gas shows enhanced turbulence consistent with low-velocity outflows. A simple expanding-bubble model indicates a strong coupling between the shock energy and the warm molecular phase. Comparable H₂ excitation signatures observed in other nearby LLAGN suggest that this subtle, yet measurable, mode of feedback may be more widespread than previously recognised.

Speaker: Ivan Ezequiel Lopez (Istituto Nazionale di Astrofisica (INAF))

95 Cracking the quasar accretion puzzle: a thin disc and an intrinsically narrow Eddington ratio distribution are enough

Quasars (QSOs) efficiently turn gravitational energy into huge luminous outputs, as matter spirals towards a supermassive black hole (SMBH) through an accretion disc. The spectral energy distributions (SEDs) of QSOs are mainly governed by few parameters, namely the SMBH mass ($M_{\rm BH}$), the accretion rate ($\dot{M}$) and the efficiency (i.e. the SMBH spin). Despite the general agreement on these very general grounds, puzzling observational findings urge a comprehensive justification. For instance, the SEDs predicted by emission line based $M_{\rm BH}$, estimated via the single epoch (SE) method, often do not agree with observations. Furthermore, extremely tight relations between broad lines and continuum luminosities (i.e. the Baldwin effect) still lack a compelling, unified explanation. In my talk, leveraging observations of some 100,000 QSOs, on a wide redshift range, I will show how these, and other inconsistencies can be naturally solved if blue optically-selected QSOs are powered by a classic geometrically thin and optically thick accretion disc with a narrow Eddington ratio distribution. Within this simple framework: 1) the observed slopes of the Baldwin effect are successfully predicted, 2) the continuum luminosity itself provides more accurate $M_{\rm BH}$ estimates than SE prescriptions, 3) super-Eddington QSOs are extremely rare, posing tight constraints on the burstiness of the super-critical accretion phases.

Speaker: Bartolomeo Trefoloni (Scuola Normale Superiore)

96 From Ultra-Fast Winds to Galaxy-Scale Feedback: a multi-phase energy-conserving outflow in IRAS 17020+4544

Outflows are crucial to AGN feedback, transporting mass and energy from the nucleus to the host galaxy across various scales. Theoretical models suggest that sub-relativistic Ultra Fast Outflows (UFOs), which interact with the ISM, decelerate and lose ionization, potentially driving large-scale, multi-phase outflows observable in optical and molecular gas.
The Narrow Line Seyfert 1 galaxy IRAS 17020+4544 offers a rare local laboratory to study AGN-driven outflows in action. It hosts a complex X-ray Ultra Fast Outflow (UFO), a powerful cold molecular outflow spatially resolved in CO with NOEMA millimeter observations, and a low-power radio jet that may be driving shocks into the interstellar medium (ISM).

In this work, we present MEGARA/GTC optical IFU observations of the ionized gas component over an area of ~140 kpc^2, within the region covered by the molecular outflow. We perform a detailed kinematic and energetic analysis of the ionized outflow and compare it from X-ray to mm bands. We find that the ionized phase is consistent with an "energy-conserving" regime, in agreement with previous results for the molecular component (Longinotti et al. 2023). These findings indicate that the different gas phases are dynamically coupled and support a scenario in which powerful AGN-driven winds efficiently transfer energy to the host galaxy.
Intriguingly, we also find evidence of positive feedback in the central regions, suggesting that the outflow may not only expel gas but also compress it, potentially triggering star formation. Overall, our results provide new insight into the multi-phase nature of AGN feedback and its impact on the evolution of Narrow-Line Seyfert 1 galaxies.

IRAS 17020+4544 thus stands out as one of the very few systems in which a multi-phase outflow associated with a UFO is observed to follow an "energy-conserving" regime across different gas phases, offering a rare benchmark for testing AGN feedback models.

Speaker: Enrica Bellocchi (Universidad Complutense de Madrid - IPARCOS)

11:00 Coffee break

S7 - The Early Growth of Supermassive Black Holes: Examining the formation, growth rates, and census of SMBHs in the high-redshift universe (z>6) and their role in cosmic reionization

Convener: Guido Risaliti (Università di Firenze. Dipartimento di fisica e astronomia)

97 (Highlight) Pushing the redshift frontier: Discovery and Characterization of Quasars at Cosmic Dawn with Euclid

Quasars at the highest redshifts illuminate the Universe during its first billion years and provide crucial insights into the formation of the earliest supermassive black holes, galaxy evolution, and the epoch of reionization. In this talk, I will present recent advances in discovering and characterizing these distant beacons at the edge of cosmic time. Special attention will be given to recent discoveries from the Euclid mission, which is dramatically opening new windows on the distant Universe through its unprecedented combination of survey area and depth. I will show that in 1.5 years of the Euclid mission, the high-z quasars team has doubled the number of z>7 known quasars, pushing the redshift frontier further into the epoch of reionisation and breaking the record twice. Following discovery, comprehensive multi-wavelength follow-up is essential to unlock the physical properties of these extreme objects. I will showcase observations in the optical and near-infrared regime, to confirm redshifts and probe the black hole masses and accretion properties and sub-millimeter observations to constrain the dust emission and the star formation rate in the host galaxies. This latter will be focused on a particular UV-faint Euclid-discovered quasar which we found to be hosted by a very massive and star-forming galaxy. Together, these multi-wavelength observations paint a detailed picture of the most luminous objects in the early Universe and their host galaxies.

Speaker: Silvia Belladitta (Max Planck Institute for Astronomy)

98 AGN-heated dust revealed in (most) Little Red Dots

Little Red Dots (LRDs) represent one of the most enigmatic source classes discovered by JWST. The origin of their compactness, X-ray/radio weakness, and V-shaped spectra remains a subject of intense debate. In this talk, I will present compelling evidence that hot (~800 K) dust emission dominates the rest-frame NIR (1-3 um) at a population level. By performing median stacking of NIRCam and MIRI images of a large (N~300) and homogeneously-selected sample of LRDs across major legacy fields (PRIMER, JADES, and CEERS), we reveal a rising NIR slope up to rest-frame 3 um (i.e. MIRI 18um/21um bands at z~6). This feature is best explained by a standard dusty AGN structure. While the LRD population is likely heterogeneous, our findings indicate that the majority (>50%) exhibit AGN-heated dust emission, irrespective of whether their optical/UV continuum is stellar- or AGN-dominated. The combination of our best-fit AGN template and non-detections in deep Chandra stacks suggests that the observed X-ray weakness is caused by heavy gas obscuration within the dust sublimation radius (<0.1 pc). We conclude by discussing recent radio-VLBI follow-ups and new observing strategies to reach a more comprehensive census of the LRD population.

Speaker: Dr Ivan Delvecchio (INAF-OAS)

99 Independent evidence for evolving dark energy from high-redshift AGN probes

The discrepancy in the Hubble constant (H0) measurements between the local and early Universe, commonly referred to as the "Hubble tension", has now reached a statistical significance of 4-7σ. This suggests potential physics beyond the flat ΛCDM model. In this talk, I present compelling observational evidence for evolving dark energy derived from a new sample of Active Galactic Nuclei (AGN) cross-matched from SDSS and XMM-Newton. By analysing the Hubble diagram of ~1,900 AGN up to redshift z~3.5, we find significant deviations from the standard cosmological model. To validate these results, I compare our findings with a separate AGN-based Hubble diagram across a similar redshift range, which utilises the relationship between variability amplitude, characteristic timescales, and intrinsic luminosity.
This is the first time that two entirely independent methodologies using AGN as standard(isable) candles have yielded consistent results. These findings provide robust support for an evolving dark energy component and a necessary revision of the standard cosmological framework.

Speaker: Elisabeta Lusso (Università di Firenze. Dipartimento di fisica e astronomia)

100 The AGN Luminosity Function at z~4 from the QUBRICS and DESI surveys

Studying AGN population at high redshifts is crucial to understanding
supermassive black hole (SMBH) formation and evolution, the
intergalactic medium (IGM), and cosmological reionization. One of the
most important observational indicators for the evolution of the AGN
population is the AGN Luminosity Function, which has been the subject
of intense study and revision in recent years. We present here a
significantly extended and more complete determination of the AGN
Luminosity Function at redshift z~4 thanks to the QUBRICS and DESI
spectroscopic surveys, with the addition of recent JWST data. This
study compiles the most comprehensive AGN Luminosity Function to date,
spanning a wide range of over ten magnitudes in UV luminosity (from
M1450=-30.0 to -18). The combined data-sets provide the most stringent
constraints to date on the AGN Luminosity Function at z~4. These new
results confirm that z~4 AGNs provide the bulk of the ionizing photons
measured in the UV background, and they are vital for studying the
redshift evolution of AGNs and constraining theoretical models of SMBH
seeding and evolution. The extended and precisely known z~4 Luminosity
Function serves as a crucial benchmark for theoretical models of AGN
and for making accurate predictions for future wide-area imaging
surveys (e.g., Euclid, Vera Rubin LSST, and Roman).

Speaker: Andrea Grazian (Istituto Nazionale di Astrofisica (INAF))

101 Out of Place: Evidence for an Off-Center Black Hole at z = 7.2

Studies of massive black holes (MBHs) have been extended to higher redshifts through recent discoveries enabled by the James Webb Space Telescope, providing key constraints on the processes governing MBH formation, commonly referred to as MBH seeding. However, the origin of the first MBHs remains uncertain, with several competing hypotheses under investigation. One leading scenario involves the formation of light MBH seeds (~100 M$_\odot$), thought to be remnants of Population III stars. Alternative scenarios propose the formation of intermediate-mass or heavy seeds at z > 7, either through runaway stellar collisions in dense star clusters or via the direct collapse of gas clouds under conditions that suppress cooling and fragmentation. Observations of high-redshift quasars further complicate this picture, as such rapid growth would require sustained Eddington-limited accretion over much of the age of the Universe, despite the expected effects of radiative feedback.

In this work, we analyze a unique system to explore potential solutions to these discrepancies. We present new JWST/NIRSpec IFU observations of a low-metallicity galaxy with a stellar mass of ~10$^9$ M$_\odot$ at z = 7.2, harboring a black hole located ~2.7 kpc off-center. The black hole, with a mass of ~10$^8$ M$_\odot$, is accreting close to the Eddington limit and significantly impacts the host galaxy, driving variations in the ionization parameter and producing clear spatial gradients from its position. With these results we provide new constraints on black hole growth and feedback in the early Universe.

Speaker: Sandra Zamora (Scuola Normale Superiore di Pisa)

102 The WISSHFUL XMM Heritage Program: probing accretion and ejection in luminous QSOs at Cosmic Noon

Ultra-Fast Outflows (UFOs) are believed to be the nuclear drivers of AGN feedback, yet their properties at the peak of SMBH growth (z$\sim2-4$) remain largely unconstrained. WISSHFUL is a 2.3 Ms XMM-Newton Multi-year Heritage Program targeting 15 luminous (L$_{bol} > 10^{47}$ erg/s), non-lensed QSOs selected from the WISSH sample, complemented by coordinated NuSTAR Large Programs and rest-frame UV spectroscopic campaigns. I will present the first-year results from this program. In the super-Eddington QSO WISSH J0900+4215 ($z = 3.29$), we report the detection of a two-component UFO at v$_{out} \sim 0.1c$ and $\sim0.3c$ - the highest-redshift UFO discovered in a non-lensed QSO - with stratified variability and extreme energetics (E$_{kin}$ up $\sim10$% L$_{bol}$). The broadband XMM-Newton+NuSTAR analysis of the full year-1 sample (7 sources) reveals low high-energy cutoffs (E$_{cut} \sim 80$ keV), pointing to cold coronae in highly accreting sources, and extending the coronal temperature-$\lambda_{Edd}$ anticorrelation to unexplored luminosities. I will also discuss emerging connections between UV absorbers (BALs/NALs) and X-ray UFOs, offering a unified view of multi-phase nuclear winds at Cosmic Noon.

Speaker: Dr Giorgio Lanzuisi (INAF-OAS)

13:05 Lunch break (lunch is not provided as part of the event)

Social events: Torre Guaceto Nature Reserve & Dinner at "Fra' Diavolo"

103 Meet at Autorità Portuale to take a bus to Torre Guaceto Nature Reserve (visit & swim)

104 Excursion: Trip to Torre Guaceto Nature Reserve

105 Dinner at "Fra' Diavolo" (near Torre Guaceto Nature Reserve)

106 Bus back to Autorità Portuale

Friday 19 June

S8 - Cosmological Implications and Large-Scale Environment: Discussing the role of AGN in structure formation and galaxy evolution models, including the effect of the large-scale environment on AGN activity

Convener: Tullia Sbarrato (Istituto Nazionale di Astrofisica (INAF))

107 (Highlight) The LX-LUV relation in quasars - A New Sample

The non-linear relation between X-ray and UV luminosities in quasars, usually parametrised as log(LX) = γ log(LUV) + β,  is one of the most direct observational signatures of the coupling between the accretion disc and the X-ray corona. Beyond its astrophysical relevance, its non-linearity makes it a powerful tool for measuring cosmological distances, allowing quasars to be used as standardisable candles up to redshifts not reached by other probes. In this talk, I will present results from a new sample of ~2500 quasars with X-ray and UV measurements extending up to z~5. I will discuss how we carefully build the sample to avoid biases from reddening, obscuration, and the Eddington bias, and show that the relation parameters do not evolve with redshift, confirming that the disc-corona coupling in quasars is remarkably stable across redshifts, black hole masses, and luminosities. Furthermore, I will show how the dispersion for this new sample reaches a new record low of ~0.15 dex on average, and discuss how that can be almost entirely accounted for by variability and inclination effects, leaving little room for any intrinsic scatter. Finally, I will discuss how this new, improved sample can strengthen the cosmological implementation of quasars in combination with other probes (supernovae, CMB), and how to ensure such analyses remain free from systematic biases.

Speaker: Matilde Signorini (Istituto Nazionale di Astrofisica (INAF))

108 The "Menus" of SMBHs in the most massive galaxies: hot, warm, or cold gas?

In idealized, dynamically relaxed galaxies, groups or clusters, the central galaxy is expected to reside at the bottom of the gravitational potential well, coinciding with the peaks of the multiphase cooling gas - hot, warm, and cold - that flows in to fuel star formation and the central supermassive black hole (SMBH). However, spatial offsets between the central galaxy and these gas phases are known to occur and may significantly affect SMBH fueling. A key implication of a multiphase AGN feeding scenario is that if any gas phase directly fuels the AGN, then a sustained offset between this gas phase and the core of the galaxy should correspond to a quiescent SMBH. In this talk, I will present results from our recent study of 25 central galaxies spanning low-mass groups and high-mass clusters (13.2 < logM_500 < 14.8). Using a combination of Chandra, MUSE, and VLBA observations, we examined spatial offsets of hot and warm gas in the atmospheres of these galaxies and explored their influence on SMBH activity. Based on the presence or absence of a compact radio core (from VLBA) and the distribution of multiphase gas, we found strong indications that it is the warm gas peaking at the galaxy’s center – rather than the hot X-ray gas – that plays a decisive role in triggering SMBH activity. I will conclude by showing early results on the cold molecular phase from archival and new ALMA observations of CO around these galaxies. Our work represents a step forward in linking the active/quiescent state of the central SMBH of the most massive galaxies to all the gas phases involved in the baryon cycle.

Speaker: Dr Francesco Ubertosi (Università di Bologna)

109 Quantifying the AGN enhancement in z>2 protoclusters

Galaxy protoclusters (PCs) at $z\gtrsim2$ are dense regions extending up to few Mpc in which massive cold gas and elevated rates of galaxy interactions trigger intense, often dust-obscured, star formation in the member galaxies. These mechanisms are also expected to promote super-massive black hole (SMBH) growth, but this possible environmental effect remains unclear, largely due to the heterogeneous galaxy selections and active galactic nuclei (AGN) identification methods employed in previous studies.
In this talk, I will present the results of the first statistical study that quantitatively assess the impact of PC environment on SMBH growth and the physical mechanisms that drive the AGN enhancement in PCs relative to a homogeneously selected control sample of field galaxies. We find a statistically significant ($\approx3\sigma$) enhancement of X-ray AGN in PCs by $\approx3\times$ in excess to the field expectation. The field and PC galaxy samples are well matched in stellar mass, star-formation rate, and dust mass, indicating that the observed enhancement is not driven by selection effects or systematically higher host stellar masses. Our results provide quantitative and unbiased evidence that the dense PC environment enhances the AGN incidence beyond what is expected from host galaxy properties alone, likely through increased gas availability and interaction-driven fueling, allowing us to take a step forward toward a full understanding of the impact of the large-scale environment on SMBH and galaxy evolution.

Speaker: Monica Natalia Isla Llave (Istituto Nazionale di Astrofisica (INAF))

110 Bright Beacons in the Cosmic Web: Cosmology with QUBRICS

Speaker: Stefano Cristiani

11:05 Coffee break

S8 - Cosmological Implications and Large-Scale Environment: Discussing the role of AGN in structure formation and galaxy evolution models, including the effect of the large-scale environment on AGN activity

Convener: Tullia Sbarrato (Istituto Nazionale di Astrofisica (INAF))

111 First results from the Study of QUasar Environment at Early-z Epochs (SQUEEzE)

Simulations and theory struggle to explain the existence of supermassive black holes at z>6, i.e. after less than 1 Gyr after the Big Bang, but all models expect that they formed in the most massive haloes of the early Universe. A direct and testable consequence is that z>6 quasars should be surrounded by overdensities of galaxies extending up to 8 Mpc, but observational studies returned inconsistent results. This is possibly due to the limited FoVs of the instruments often used, that do not trace such spatial scales. In fact, the few studies that employ wide FoV imagers, such as LBT-LBC, always detect significant galaxy overdensities around high-redshift QSOs, but the interpretation of these results is limited by the small number of covered QSO fields.  SQUEEzE is an ongoing INAF LBT Strategic Program that collected optical (LBT-LBC) and IR (CFHT-WIRCAM) multi-band photometry of the fields of ~15 quasar at z~6 to identify high-redshift Lyman-break galaxies and perform the first statistical study of the z~6 quasar environment up to 8 Mpc scales. The targeted quasars span wide ranges of BH mass, luminosity, and radio loudness, allowing us to investigate secondary trends of the environment with such quantities. In this talk, I will present the program and show the first results on a subsample of fields.

Speaker: Virginia Lucia Cavicchi (Istituto Nazionale di Astrofisica (INAF))

112 HIDE AND SEEK: cosmic evolution of the ISM and its implications for nuclear obscuration.

Recent observations carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) show that the density of the galaxies' interstellar medium (ISM) increases toward earlier cosmic epochs, evolving approximately as $(1+z)^{3.3}$. At $z>3$, the gas column density along the nuclear line of sight can exceed by more than two orders of magnitude the typical values observed in local galaxies, reaching conditions close to the Compton-thick regime at $z\geq6$. This scenario suggests that the ISM of the host galaxy may substantially contribute to the obscuration of accreting supermassive black holes in the primordial Universe, hiding them and their properties from the seeker.

Here I will discuss the evolution of the ISM column density in galaxy samples at different redshifts, extending the analysis up to $z>9$ thanks to observations with the James Webb Space Telescope (JWST).

A number of probes have been investigated to estimate the ISM column density in these samples, including the analysis of the sub-millimeter continuum emission from cold dust, the use of line tracers such as [CII], and an indirect method based on the Schmidt–Kennicutt relation and its possible evolution with redshift, which allows the gas surface density to be derived from the measured star formation rate. In all three approaches, the estimation of the surface gas density requires spatial information about the sources, in particular the characteristic size of the gas distribution or of the star-forming region.
Observations of objects at high (sub-arcsec) angular resolution were therefore considered, including galaxies and high-redshift quasars from ALMA surveys reported in the literature, and sources selected by JWST within the COSMOS-Web survey area. For each subsample, the ISM density was measured according to the available tracers, allowing a comparison between the different approaches.

The comparative analysis made it possible to assess the robustness of the estimates, the main sources of uncertainty, and the impact of the methodological assumptions.

Preliminary results confirm that the gas column density tends to increase with redshift, suggesting that the ISM of the host galaxy may represent a dominant component of AGN obscuration. These findings have important implications not only for understanding the growth history of hidden supermassive black holes, but also for constraining the processes that regulate the evolution of galaxies and their interstellar medium in the early Universe.

Speaker: Lucia Fiorani (Università di Bologna)

113 Exploring radio processes in hyperluminous quasars at cosmic noon

Our study focuses on Hyper-luminous Quasars (HyLQSOs), highly accreting SMBHs at z$\sim$2-4.5 ("cosmic noon”), which drive powerful AGN feedback via extreme energy release.
The WISSH project studies 85 of these sources (LBol$\geq 2\times 10^{47}$ erg/s), confirming they host massive SMBHs ($M_{BH}\geq 2\times 10^{9} M_{\odot}$) and launch powerful, high-velocity outflows (up to 50,000 km/s). They are often X-ray weak due to shielding by these winds.
Radio observations provide fundamental information to investigate accretion/ejection coupling, the presence of jets and the interplay between jets and powerful winds. This is key to understanding the radio-loud/radio-quiet dichotomy across cosmic epochs.
We are conducting a radio survey (uGMRT/JVLA) of the WISSH sample revealing a new, highly luminous population. Interestingly, the detected radio emission, being more predominant than the X-ray emission, appears to be linked to outflows (winds or jets), even though most sources are formally radio-quiet. The WISSH sources offer the opportunity to test a possible analogy with high-state X-ray binaries, using the radio loudness/Eddington rate relation to constrain the universal physics of accretion-driven outflows.

Speaker: Matteo Fanelli (Istituto Nazionale di Astrofisica (INAF))

114 Early Black Hole Growth via Super-Eddington Accretion: insights from High-Resolution Simulations

Speaker: Alessandro Trinca

S9 - Current and Future Facilities for AGN Science: Discussing the implementation and scientific exploitation of major current and future space-based and ground-based facilities with Italian involvement, focusing on maximizing their impact on AGN studies

Convener: Tullia Sbarrato (Istituto Nazionale di Astrofisica (INAF))

115 (Highlight) The Cherenkov Telescope Array Observatory and its gamma-ray view on Active Galactic Nuclei

The forthcoming Cherenkov Telescope Array Observatory (CTAO) will be the first facility based on Imaging Atmospheric Cherenkov Telescopes (IACT) to be operated as an observatory open to the community through open calls for observing time and public data access. With arrays of large multiplicity, three classes of telescopes, and state-of-the-art technology implemented end-to-end, CTAO will significantly enhance sensitivity as well as angular and energy resolution compared to currently operating experiments such as MAGIC, H.E.S.S., and VERITAS. It will operate across an unprecedented passband, ranging from a few tens of GeV up to 100 TeV. With the two sites of CTAO-N in La Palma, Canary Islands, and of CTAO-S in Chile, CTAO will have full access to both the Northern and Southern sky. These features will expand enormously the power of IACT observations in all the science topics, including AGNs. In this talk I will briefly present the CTAO, the timeline for its implementation, and the adopted policies for distributing the observing time and allowing data access. Then I will focus on the perspectives for science in the field of Active Galactic Nuclei, also in the context of a multi-wavelength and multi-messenger approach. A glimpse on some themes of fundamental physics and cosmology that can be tackled through these observations will be given as well.

Speaker: Giacomo Bonnoli (Istituto Nazionale di Astrofisica (INAF))

12:55 Lunch break (lunch is not provided as part of the event)

S9 - Current and Future Facilities for AGN Science: Discussing the implementation and scientific exploitation of major current and future space-based and ground-based facilities with Italian involvement, focusing on maximizing their impact on AGN studies

Convener: Prof. Cristian Vignali (Dipartimento di Fisica e Astronomia, Università di Bologna)

116 The sharp high energy sky seen by XRISM

XRISM was successfully launched in September 2023 and in just its first two years of observations the Resolve data are providing a unique high-resolution view of the innermost regions of AGN and are poised to revolutionize our knowledge of them. XRISM-Resolve’s piercing energy resolution of 5 eV now enables precise line width and velocity measurements, with no degeneracies between column density and ionization, thus allowing for a detailed mapping of the velocity field of the emitting and absorbing regions in AGN. Early XRISM results already reveal unexpectedly rich spectra; structures that were previously blurred into just a few spectral bins in the CCD era are now fully revealed in exquisite detail. Here, I will highlight the main results obtained on early observations of nearby bright AGNs, from the best examples of unobscured AGN to Compton thick cases and the prototypes of the ultra-fast disk winds.

Speaker: Valentina Braito (Istituto Nazionale di Astrofisica (INAF))

117 (Highlight) Investigating AGN in the SKA Era

Speaker: Isabella Prandoni (Istituto Nazionale di Astrofisica (INAF))

118 (Highlight) NewAthena

Speaker: Luigi Piro (Istituto Nazionale di Astrofisica (INAF))

119 (Highlight) KM3NeT/ARCA: status, recent results and perspectives for AGN studies

KM3NeT is a deep-sea neutrino observatory under construction in the Mediterranean Sea. The experiment comprises two Cherenkov detectors: ARCA, optimised for the detection of TeV–PeV neutrinos, and ORCA, dedicated to the measurement of neutrino oscillation parameters. The construction of ARCA is progressing steadily, and the detector is already delivering competitive physics results in its partial configuration. At present, the array comprises about 25% of the final instrumented volume. Even at this stage, the detector has demonstrated excellent performance in reconstructing high-energy neutrino events. A major highlight is the recent observation of an extremely energetic neutrino candidate with a reconstructed energy of about 220 PeV, the most energetic neutrino event detected to date. ARCA offers strong discovery potential for high-energy neutrinos from Active Galactic Nuclei. This contribution provides an overview of the status of the KM3NeT infrastructure and recent scientific results, emphasising the implications for AGN studies in the framework of multi-messenger astronomy.

Speaker: Dr Simone Biagi (INFN, Laboratori Nazionali del Sud)

120 (Highlight) The IXPE revolution in AGN: from the hot corona to the torus

The Imaging X-ray Polarimetry Explorer (IXPE) has opened a new observational window on Active Galactic Nuclei (AGN), adding X-ray polarimetry to spectroscopy and timing as a fundamental diagnostic of their central engines. By directly probing geometry, IXPE is providing the first constraints on the structure of both the hot corona and the obscuring torus in radio-quiet AGN.
In Seyfert 1 galaxies, joint observations with XMM-Newton, NuSTAR, and Chandra have revealed significant X-ray polarization and polarization angles aligned with the radio jet axis, favoring radially extended coronal geometries. In Compton-thick Seyfert 2 AGN, high polarization degrees (15–20%) provide direct evidence that the primary scatterer is a geometrically thick equatorial torus, as predicted by AGN unification models.
These results demonstrate that X-ray polarimetry has become a powerful and direct probe of AGN structure, from the compact corona to the parsec-scale obscuring material surrounding supermassive black holes.

Speaker: Dr Vittoria Elvezia Gianolli (Clemson University)

121 (Highlight) The AGN content in eRASS/DR1 and eRASS/DR2

Abstract: Galaxy evolution can only be understood if its AGN phases are accounted for. For that, a complete and pure census of AGN is needed. Hunting for AGN in X-rays is the most obvious way to go, given the low emission from galaxies at this frequency. Over the last 20 years, XMM and Chandra have mostly provided pencil-beam surveys, thus sampling the faint and high-redshift regimes. Finally, with eROSITA, we can also sample the rare (local and z>5.5) and faint Universe. In my talk, I will then review the multi-wavelength properties (including redshifts) of the first eROSITA/DR2 AGN sample (data release planned for July 2026) and compare them with AGN selected from other surveys and from eRASS/DR1.

Speaker: Mara Salvato (MPE)

Closing Remarks and End of Conference

Convener: Prof. Cristian Vignali (Dipartimento di Fisica e Astronomia, Università di Bologna)

122 Concluding remarks

Speaker: Andrea Merloni

Social events: Teatro Scienza Special Event - "Crazy Space" - Teatro Verdi (Brindisi)