Detailed Programme

The expansion of Active Galactic Nuclei (AGN) research globally requires deliberate inclusion of emerging institutions, particularly in underrepresented regions. This contribution presents an early-stage case study of capacity building in AGN and extragalactic astronomy at Meru University of Science and Technology (Kenya).

At the postgraduate level, AGN-related training is currently embedded within a broader MSc curriculum in extragalactic astronomy, with one ongoing MSc research project directly focused on AGN. In parallel, a small cohort of postgraduate students is engaged in radio astronomy, providing a complementary pathway toward future AGN-related research. At the undergraduate level, exposure to astrophysics is limited to a single course, Introduction to Astronomy, highlighting both the constraints and opportunities for growth.

Despite limited infrastructure, funding constraints, and a shortage of specialized personnel, targeted efforts in mentorship, curriculum development, and participation in international training workshops have begun to create awareness and interest in AGN science. These efforts aim to establish a foundational pipeline through which students can progressively engage with extragalactic and AGN research.

We discuss practical strategies for strengthening AGN capacity in such contexts, including incremental curriculum integration, leveraging radio astronomy as an entry point, and building international collaborations aligned with large survey projects.

This work highlights the importance of supporting early-stage institutional efforts as a pathway toward broadening participation in the global AGN research community.

The nuclear 50-pc region of active galactic nuclei (AGNs) is a critical site where accretion, feedback, and galaxy-scale evolution intersect, encompassing both the molecular torus and its immediate circumnuclear environment. Dense molecular gas in this region fuels star formation and AGN activity and constitutes the dominant component of the cold gas reservoir. In this study, we investigate how AGN feedback affects the morphology and clumpiness of molecular gas within the inner ~50 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 molecular gas clumpiness, we apply a modified non-parametric analysis based on the CAS (Concentration, Asymmetry, Smoothness) method, adapted for molecular line emission. While the molecular torus itself is not spatially resolved at these scales, this approach probes the physical structure of the molecular medium in which the torus is embedded. We find a systematic decrease in molecular gas clumpiness with increasing hard X-ray luminosity, with a significant transition at L_X ~ 10^{42} erg/s. This trend suggests that AGN-driven feedback, likely through outflows and AGN-induced turbulence, progressively disrupts the formation of large, dense molecular clumps in the nuclear and circumnuclear region. Our results provide observational evidence that AGN feedback reshapes the structure of the molecular medium on tens-of-parsec scales, with direct implications for the physical origin, stability, and evolution of clumpy torus models. More broadly, these findings raise questions about the role of geometric alignment — between the torus opening angle, the nuclear molecular disc, and the AGN/jet axis — in regulating the spatial distribution and survival of molecular clumps.

Heavily obscured, starbursting galaxies at z∼1–2 hosting luminous AGN and compact radio jets provide a unique laboratory to probe AGN feedback at its peak. In this contribution, we present a multi-phase view of the interstellar medium in four such systems drawn from the radio Dust-Obscured Galaxy (radio DOG) population, where VLA imaging reveals compact (∼1–5 kpc) radio jets. These objects capture a short-lived but critical phase in which rapid star formation, black hole accretion, and jet activity coexist.

Using molecular gas observations, we constrain the cold gas content and star formation efficiency to assess whether and how feedback is regulating star formation. Complementary ionized gas diagnostics (Hα and [O II]), available for one source, show line ratios and strengths consistent with shock excitation, suggestive of jet–ISM interactions. Although limited by spatial resolution, this analysis enables a global assessment of how mechanical and radiative feedback couple to the ISM.

These results provide new constraints on the role of compact jets in shaping the gas reservoirs and star formation properties of massive galaxies at cosmic noon, highlighting their importance in galaxy evolution across scales.

Powerful radio-loud active galactic nuclei (RLAGN) represent the most

extreme manifestation of accretion onto a supermassive black hole and

play a crucial role in galaxy evolution. It is becoming increasingly

clear that the majority of high-z RLAGN are obscured and that they

appear as high-redshift radio galaxies (HzRGs). However, our knowledge

of HzRGs is extremely limited: only a handful of RGs at z > 4 are

known. Therefore, many questions about their properties and the

effects on their host galaxies still await answers. We recently

started a project aimed at building a well-defined sample of HzRGs. I

will review the first results obtained, in particular the finding that

their radio sources are usually compact, <10 kpc in size, suggesting

that the huge amount of energy carried by their jets is delivered on

galactic scales and hence that feedback processes in these sources are

particularly important.

Active galactic nucleus (AGN) feedback is a key process in galaxy evolution, particularly at cosmic noon, when star-formation and black-hole accretion rates were at their peak. Jets and radiation during an AGN phase can inject energy on scales of the host galaxy and the circumgalactic medium (CGM). In this context, high-redshift radio galaxies (HzRGs) are unique systems, as they host both radio jets and a luminous type-2 quasar. These objects, therefore, allow us to study, within a single source, the combined impact of jets and quasar radiation in transporting energy from the nuclear region to CGM scales. With the JWST NIRSpec IFU, it is now possible to spatially resolve the impact of AGN on the surrounding gas in the high-redshift universe (z > 3).

I will present our analysis of the high-redshift radio galaxy 4C+03.24 at z = 3.56, using NIRSpec IFU observations to resolve the properties of the ionised gas spatially.

We find clear evidence for strong jet–gas interaction at a distance of ~12 kpc from the nucleus, bending the radio jet. We detect dense gas clumps, extending over a ~2 kpc region with electron densities of ~4300 cm^-3, that are likely responsible for the observed jet deflection. We find shock ionisation in the surrounding region due to this jet-gas interaction. Overall, we investigate the ionisation mechanisms in the entire system, out to a radial distance of ~15 kpc, tracing gas on CGM scales. A detailed comparison of the observed lines with radiative shock models reveals evidence for large-scale shocks in this system. The shock-ionised gas is distributed perpendicular to the inner jets and AGN ionisation cone, and we also detect precursor emission associated with gas-rich regions. These shocks significantly disturb the ionised gas, generating turbulence with FWHM line widths of 1000–2000 km s⁻¹.

The observed electron densities and Balmer line luminosities are consistent with shock model predictions, supporting their origin in post-shock, radiatively cooling gas. We estimate that shocks ionise and disturb ~40% of the gas mass in this system, and contribute significantly to both the energy budget and the mass of the disturbed ionised medium. This demonstrates that jetted AGN at high redshift can drive shocks into the large-scale medium, and highlights how observations from next-generation facilities can be directly compared with models to constrain AGN feedback in the high-redshift universe.

While large-scale relativistic jets have often been invoked as an efficient feedback mechanism in galaxy evolution, radio-loud AGN represent a minority of the AGN population. Indeed, increasingly sensitive facilities have clearly revealed that most AGN (~90%) have low radio powers (<10^23 W/Hz). The detection of kiloparsec-scale radio outflows in these sources, accompanied by multi-phase (atomic, ionised, molecular) winds, suggests they may play a main role in shaping galaxy evolution. Understanding whether the radio outflows are powered by accretion-disk winds or jets, and their interplay with different outflow phases, remains challenging and requires high resolution multi-wavelength observations.

In this talk, I will present key results on XID2028, a well known obscured quasar at z=1.59, where multi-wavelength observations show one of the clearest evidence of mutual connection between the different outflow phases at the cosmic noon.

In particular, I will show new sub-arcsecond resolution VLA images that, by resolving for the first time a symmetric three-component morphology, allowed a spatially resolved spectral analysis. I will then discuss the nature of the radio emission (wind or jet), and how the radio analysis supports the recently proposed scenario where the extended (~13 kpc) [OIII] outflow, detected by JWST/NIRSpec, can be modelled by an expanding bubble driven by a collimated outflow. I will finally present the analysis of new JWST/MIRI spectra with the derived constraints on the ongoing feedback, and how all these results relate to the already known CO outflow detected with ALMA.

This study anticipates the capabilities of SKA and ngVLA to routinely observe low radio-luminosity AGN at cosmic noon, a key step toward bridging the gap between high-redshift radio-loud and local radio-quiet populations.

Radio jets are among the most powerful agents of feedback in the Universe, capable of suppressing star formation and regulating the growth of their host galaxies across cosmic time. Understanding how jets couple to the interstellar medium and shape galaxy evolution remains one of the central open questions in extragalactic astrophysics, particularly for the low-luminosity and compact radio-AGN population. Addressing this requires statistically robust, multi-wavelength studies over large samples that span wide ranges of redshift, radio power, and environment.

To this end, we present J-HERTz (J-PLUS Heritage Exploration of Radio Targets at z < 5), a new public multiwavelength catalog combining optical narrow-band photometry from J-PLUS, low-frequency radio data from LoTSS, and infrared detections from WISE for nearly 500,000 sources over 2100 deg² in the northern sky. The catalog provides Bayesian neural network classifications of galaxies, QSOs, and stars, photometric redshifts, optical-to-IR radio-loudness indicators, stellar masses, and star formation rates, making it a powerful tool for population-level studies of radio-AGN and their hosts.

Exploiting this dataset, we find that radio-loud galaxies show clear signatures of suppressed star formation relative to radio-quiet systems with similar properties, consistent with AGN feedback driving galaxy quenching. Approximately 20% of radio-loud galaxies are optically quiescent, hosting radio cores whose activity leaves no imprint on their optical spectra, suggesting jet-dominated feedback operating in a radiatively inefficient regime. We also find statistical evidence for a perpendicular alignment between VLBI pc-scale jets and the optical morphology of their hosts, a trend that persists in LOFAR kpc-scale jets, pointing to a coherent jet-host connection spanning over four orders of magnitude in physical scale. Finally, we are extending the analysis to higher radio frequencies to constrain jet spectral ages, morphologies, and the fraction of AGN remnants — sources with no nuclear emission but visible low-frequency radio lobes — providing new diagnostics for jet duty cycles and their cumulative impact on host galaxies.

Understanding how compact radio outflows couple to the interstellar medium is central to linking jet activity to AGN feedback. Recent ALMA observations of nearby (z ∼ 0.1) obscured quasars reveal disturbed molecular gas kinematics, enhanced excitation, and outflows co-spatial with regions of high CO line ratios. While the inferred mass outflow rates are lower than expected from AGN luminosities, the jet coupling efficiencies indicate that radio-mode feedback may be an important mechanism in these systems, highlighting the need to investigate the nature of the radio emission in these targets.

In this talk, I will present results from a new high-resolution, multi-band VLA radio continuum campaign targeting a sample of type-2 quasars from the QSOFEED survey. Despite being classified as radio-quiet, most sources exhibit structured radio morphologies, including compact jets on kiloparsec scales embedded within diffuse emission extending up to ∼50 kpc. These results demonstrate that jet-like radio structures are ubiquitous in quasars with intermediate radio luminosities and open a new window on the role of low-power jets as drivers of AGN feedback on galaxy scales.

The LOFAR surveys have given us the largest ever sample of radio-selected AGN and we have been developing methods to infer their jet power and environmental impact from their radio and environmental properties. While radio AGN can clearly offset the cooling of hot gas at z~0, the cosmic evolution of the AGN kinetic luminosity function is still an interesting topic and I will present the latest results on this and on the environment-dependent kinetic luminosity function, together with a look ahead to the prospects for combining new LOFAR surveys and Euclid optical data.

Understanding how supermassive black holes (SMBHs) grow and how the energy they release shapes their environments remains one of the central challenges in galaxy evolution. Processes spanning from sub-parsec accretion physics to the large-scale intracluster medium (ICM) must ultimately be understood as part of a coherent, multi-scale picture, yet bridging these scales in a single simulation framework remains a formidable numerical challenge. I will present results from a suite of simulations performed with the moving-mesh code AREPO, combining super-Lagrangian refinement (SLR) with novel sub-grid accretion disc models that self-consistently drive jets and winds, allowing us to follow SMBH growth and feedback across an unprecedented dynamic range.

On the largest scales, I will present high-resolution jet feedback simulations within cosmologically evolved cluster environments, revealing how jets and their inflated lobes interact with the dynamic ICM. I will discuss how cluster weather influences lobe disruption and energy transport, how magnetic fields suppress mixing and extend lobe lifetimes, and how these processes combine to determine the net efficiency of jet feedback. I will also present work exploring AGN-triggered cooling, examining the physical conditions under which jet-driven turbulence can promote rather than suppress gas cooling, providing new insight into the self-regulating nature of feedback in cluster environments. Mock X-ray and radio observables offer direct tests for current and upcoming facilities.

Zooming in, I will present simulations of jet feedback in low-mass systems, where jets launched from sub-grid accretion discs, using spin-based models, interact with the interstellar medium, which directly impacts the energetic outflows that emerge. I will discuss the properties of these outflows as well as the feedback efficiency in these environments, highlighting how jet power, morphology, and coupling to the surrounding gas depend sensitively on the local environment and jet properties. I will conclude by outlining key open questions and future directions for connecting simulation predictions with high-resolution radio, X-ray, and IFU observations.

We present a multiwavelength study of two powerful tailed radio galaxies located in the core of a massive, dynamically young galaxy group at z = 0.35 in the COSMOS field. The system was first identified through the discovery of a wide-angle tail (WAT) and a head–tail (HT) radio galaxy associated with an X-ray–detected galaxy group. Our analysis shows that the group is a dynamically unrelaxed system undergoing early-stage assembly through group–group merging.

Using broadband radio data from Karl G. Jansky Very Large Array (VLA), MeerKAT, and Giant Metrewave Radio Telescope (GMRT), spanning 325 MHz to 3 GHz, together with optical imaging from the Hubble Space Telescope (HST), high-quality photometric and spectroscopic redshifts from COSMOS, and X-ray observations from Chandra X-ray Observatory and XMM-Newton, we investigate both the group environment and the detailed radio spectral properties and aging of the radio galaxies.

The two radio galaxies are hosted by massive elliptical galaxies, corresponding to the brightest and second-brightest group members, and are embedded in a hot (Tₓ ≈ 2.4 keV), irregularly distributed intragroup medium (IGM). Our analysis of the jet bending indicates significant bulk motions, consistent with an ongoing merger. Spectral index analysis reveals steepening of the radio spectrum with increasing distance from the core in both galaxies, with localized spectral flattening indicative of particle re-acceleration in the WAT lobes and hotspots along the northern jet, and indications of similar flattening in the middle of the HT tail.

We find a significant discrepancy between spectral and dynamical age estimates, with dynamical ages exceeding spectral ages by factors of ~7-20. This discrepancy highlights the limitations of dynamical aging models that assume constant expansion speeds and underscores the importance of accounting for environmental effects and lobe-IGM interactions. Together, these results demonstrate how tailed radio galaxies can serve as sensitive tracers of dynamically young systems and provide new insight into AGN feedback and energy deposition in galaxy groups.

For decades, the “cooling flow problem” has challenged our understanding of galaxy evolution on the largest scales: in galaxy clusters, the hot (10^7 K) intracluster medium (ICM) contains vast gas reservoirs, yet fuels star formation in brightest cluster galaxies (BCGs) with only 1–10% efficiency. Feedback from accreting active galactic nuclei (AGN) in those BCGs is widely accepted as the heating mechanism that suppresses such runaway cooling by up to two orders of magnitude. While numerous studies have established a link between excess ICM cooling and AGN feedback, most have focused on nearby, low-redshift systems. We extend these works via a multi-wavelength analysis of BCGs drawn from Sunyaev–Zel’dovich-selected clusters spanning ~10 Gyr of cosmic evolution. This dataset includes extensive follow-up from Chandra, Magellan, ATCA, and other facilities, enabling a systematic study of BCG growth channels, feedback efficiency, and ICM cooling conditions across cosmic time. In this talk, we show that while some aspects of this cycle remain remarkably stable, others evolve significantly in the high-redshift regime, where clusters are still assembling and AGN transition between radiative and jetted feedback modes.

Galaxy evolution is regulated by a delicate balance between gas accreting from the intergalactic medium and gas expelled back into it. Active Galactic Nuclei (AGN) play a crucial role in maintaining or disrupting this balance as they eject enormous amount of energy (feedback) as consequence of accretion of gas onto the supermassive black holes (feeding). Yet which processes regulate gas accretion onto the SMBHs is unknown.

MAGNHIFFIC (MeerKAT AGN HI Feeding & Feedback investigation close-by) is a project acquiring some of the deepest and most sensitive HI observations (25hrs per source) of ~15 nearby AGN (D<35), with MeerKAT. These observations allow us to resolve at high spatial (10’’) and spectral resolution (1.4 km/s) the low-column density HI (~10^19 cm-2) involved in feeding and feedback phenomena of nearby AGN. Because of its large field of view (1 deg2) and constant sensitivities over all spatial scales, MeerKAT allows us to trace the diffuse HI clouds fuelling the AGN from their environment down to the circum-nuclear regions of their SMBH, as well as cold gas outflows ejected by the radio jets through the galaxy. Deep multi-band photometrical observations (mu_r~27.5) of the MAGNHIFFIC AGN are key for an unambiguous interpretation of the HI features as they allow us to determine if a stellar counterpart of the HI detections is present and they fully characterize the AGN environment by detecting all low-surface brightness satellites down to very low masses (~2x10^6 Mstar).

In this talk I will focus on the fuelling mechanism traced in 2 MAGNHIFFIC radio AGN. In NGC3100, a dark and extended (>100 kpc) HI filament from the CGM is falling onto the galaxy, replenishing its circum-nuclear disk. Multi-peaked redshifted narrow HI absorption reveals clouds falling from this disk potentially fueling the AGN. In NGC1052 the combination of deep photometry and HI MeerKAT observations reveals a trail of ultra diffuse galaxies that has formed interacting with the galaxy, leaving an HI tail now fuelling its AGN.

Extended warm and cold gas nebulae, with complex morphologies and kinematics, have been observed in the centres of cool-core galaxy clusters. Their origin within the hot intracluster medium (ICM) is still puzzling, and among many mechanisms, positive feedback from the central active galactic nucleus (AGN) has been proposed.

In this work, we performed a suite of very high-resolution hydrodynamic simulations of a Perseus-like cool-core galaxy cluster subject to self-regulated AGN jet feedback, which leads to realistic ICM properties. By explicitly following warm ionized, neutral, and molecular gas phases, we studied the complex interplay between AGN activity and the multi-phase ICM.

During the talk, I will illustrate a physical mechanism through which kinetic jet feedback contributes to the formation of the extended warm and cold gas nebulae at the center of cool-core galaxy clusters. While AGN feedback globally heats the ICM, during the individual AGN jet bursts, we find that hot material is also injected laterally to the jet axis, within the turbulent mixing layer. This material, as it expands, compresses the surrounding hot ICM, reducing the local cooling time, and leads to the formation of cold clumps on a characteristic timescale of ~ 30 Myr. By employing tracers, we explicitly track cooling within the affected regions, finding that very hot gas identified in high-compression, low-vorticity zones condenses in situ to form cold clumps. A statistical analysis reveals that the condensation of cold gas is highly promoted once the local turbulent Mach number, σ/c_s, in the hot gas component (T > 10^7 K) takes values around ~ 0.3.

The presented process is a further important step in understanding the physical mechanisms that lead to the formation of cold gas in the cluster core and how they are linked with the central AGN activity. Our measured values of the characteristic turbulent Mach number, together with detailed multi-phase gas kinematics predictions, provide important theoretical tools to interpret future X-ray spectroscopy and deep radio data, ultimately to constrain the origin of cool-core cluster nebulae and their relation with AGN feedback.

We report the serendipitous discovery of a highly compact odd radio circle (ORC)-like source in the LOFAR Two Metre Sky Survey. The source comprises a bright, well-defined ring of radius ~9 arcsec (~30 kpc), embedded within a faint diffuse envelope extending to ~1 arcmin (~200 kpc). Its likely host is the most massive galaxy in a group at z = 0.2.

Both the morphology and spectral properties disfavor an origin linked to either an active or dying radio galaxy. Instead, we interpret the emission as fossil radio plasma re-energized by shocks in a dynamically active group environment. However, the combination of compact size and high luminosity is difficult to reconcile with current models.

This object pushes ORCs into a previously unexplored regime of parameter space, indicating that they can occur on substantially smaller physical scales. The detection of an extended, low-surface-brightness envelope further suggests that aged electron populations may be more prevalent than currently recognized, but often missed at higher frequencies.

We place this source in the context of the known ORC population and outline future avenues to discriminate formation scenarios, characterize their diversity, and establish ORCs as probes of the intragroup medium and of the radio plasma lifecycle.

Powerful, radio-loud AGN are associated with one of the most important forms of AGN feedback, and understanding how they are triggered is key to properly incorporating them into models of galaxy evolution. They can be characterised by their accretion modes, with the radiatively-efficient radio AGN (e.g. high-excitation radio galaxies; HERGs) accreting at a high Eddington rate (>1%), in contrast with their radiatively-inefficient counterparts (e.g. low-excitation radio galaxies; LERGs) at much lower Eddington rates. Previous studies have provided some evidence that the dominant triggering mechanisms vary between these subtypes, but at low levels of statistical significance. Here, I present the results of a deep INT/WFC imaging survey which, when combined with Gemini/GMOS-S images, gives a 98 per cent complete sample of 112 3CR radio galaxies with redshifts z < 0.3, alongside a stellar mass matched control sample. Our results provide strong evidence for significant differences (>3σ) between the triggering mechanisms of the different sub-types of powerful radio AGN. The HERGs show a high rate of morphological disturbance – an excess of ~4σ compared with the control sample – consistent with them being predominantly triggered in galaxy mergers and interactions. In contrast, the LERGs show a much lower rate of morphological disturbance, consistent with the control sample, and suggesting a different triggering mechanism, such as the accretion of gas from the hot X-ray haloes of the host galaxies or galaxy clusters. We also demonstrate that, when considering their radio morphology, the FRII HERG sources preferentially reside in disturbed morphologies, a difference of ~3σ to the FRII LERG objects. This suggests that the FRII LERG sources do not solely represent a ‘switched-off’ phase in the HERG lifecycle of the same parent galaxy population as the FRII HERGs.

We present results from a study of 30+ nearby AGN observed with both VLT/MUSE and the VLA, designed to test whether compact radio structures in radiatively dominant AGN are best interpreted as classical jets or as shock signatures from outflow-ISM interactions. We model the [O III] emission-line profiles with multiple Gaussian components to isolate distinct kinematic structures and compare their morphology and orientation to the radio continuum. We find that [O III] outflows are commonly aligned with the radio emission, indicating a strong physical connection between ionized gas kinematics and radio structure. However, unlike earlier studies based on non-parametric line-width measurements, we find that the broad [O III] component is often distributed isotropically around the nucleus rather than preferentially perpendicular to the radio axis. Compact radio sources also tend to be associated with circular or isotropic outflow regions, and in systems where the SMBH outflow is strongly coupled to the host, the ionized outflow often extends beyond the radio-emitting region. In many galaxies, the radio structure is aligned with bright host-disk material, suggesting that dense ambient gas plays a major role in shaping the observed morphology. These results support a picture in which compact radio emission in many radiatively efficient AGN is not produced by a relativistic jet alone, but instead traces shocks generated as AGN-driven outflows interact with extended host-galaxy material.

We present a comprehensive analysis of the ionized gas in the kpc-scale extended emission line region (EELR) of NGC 5972, a Seyfert type-2, “Voorwerp galaxy.” Voorwerp galaxies, is an unique class of galaxies discovered by citizen scientists in the Galaxy Zoo project, are particularly interesting in the context of AGN feedback. These galaxies are characterized by their striking green emission in false color-composite images, indicating strong oxygen emission lines. Previous studies suggest that the EELR surrounding Voorwerp galaxies is primarily caused by AGN photoionization. However, the absence of a bright AGN at the center of these galaxies, capable of ionizing clouds to the observed extent, has led to the hypothesis that these are quasar ionization echoes or remnants of past quasar activity. Some sources, such as Mrk 78 and the Teacup quasar, have shown a strong correlation between the [OIII] emission line and kpc-scale radio jets. Therefore, we aim to investigate AGN-driven feedback, particularly the jet feedback mechanism in NGC 5972, to quantify the contributions of AGN photoionization versus shock ionization in the ambient ISM.

NGC 5972, features a helical-shaped EELR with a radius > 10 kpc and a S-shaped radio structure spanning about 470 kpc. We use VLT/MUSE, GMRT, and VLA to study the stellar and ionized gas kinematics and how the radio jet influences the gas in the galaxy. Our sensitive radio observations detect the southern jet for the first time, roughly coinciding with the southern EELR. The VLA images show a continuous inner jet connected to the outer E-W lobe, confirming the jet origin of the radio emission. Our kinematic analysis shows spatial correlations between the radio jet and the outflowing gas, supporting the jet-driven feedback mechanism. More interestingly, we observe enhanced velocity dispersion in the perpendicular direction along with a shell-like structure. Our BPT analysis shows that the [O III] emission overlapping with the radio jet is consistent with the shock+precursor model, whereas in the perpendicular region, a pure shock model fits well with the observations, indicating jet-induced shocks. Overall, based on our findings, we propose a jet-driven feedback mechanism as one of the key factors in the formation of the EELR in NGC 5972.

I will review the work of the DARA project that has delivered basic training in the skills associated with radio astronomy to over 500 graduates from the African SKA partner countries, including Kenya. The training includes hands-on training in radio techniques at radio observatories in South Africa and Ghana, and was recently extended to incorporate optical astronomy training at a site in northern Kenya. Trainees also gain skills in Linux, Python, and radio astronomy data reduction. Our industrial partners from the space sector showcase how such skills can be transferred into other areas such as satellite communications and remote sensing, as well as encouraging entrepreneurship. In parallel, the DARA Big Data project has trained a similar number of people in ML/AI skills via hackathons and workshops that emphasise the synergies between astronomical, Earth observation, and medical imaging applications. The DARA advanced training programme has supported over 70 Masters places and 27 PhDs, as well as 13 postdocs, in African institutions, with the aim of establishing radio astronomy groups ready to utilise and contribute to the SKA.

The supermassive black hole (SMBH) at the center of M87, the brightest galaxy in the Virgo cluster, exhibits both low luminosity and high variability. In massive galaxy clusters, SMBHs are thought to be fueled by various mechanisms, including cold chaotic accretion (CCA). However, the complexities of the CCA process remain incompletely understood, especially given the vast dynamic range. To address these challenges, we employ general relativistic magnetohydrodynamic (GRMHD) simulations of M87, using boundary conditions that mimic the infall of cold filaments and clouds, replicating the CCA scenario. Our study investigates the dynamics of gas accretion onto SMBHs, exploring the intricate interactions between turbulent cold gas flows, angular momentum cancellation, and thermalization via ADAF accretion.

By linking the small-scale physics of accretion to larger galactic dynamics, we aim to uncover the mechanisms driving variability in the mass accretion rate and their impact on galaxy evolution. In particular, the study of infalling cold gas clouds offers critical insights into the variability of the inner accretion flow, shedding light on SMBH feeding mechanisms and the resulting variability in galactic centers.

We investigate the physical conditions in the inner, jet-launching region of the active nucleus in M87. We develop a physically self-consistent model based on GRMHD simulations that incorporates electron energy balance and simultaneously reproduces the broad-band spectrum, the Event Horizon Telescope intensity images, and the variability properties of this source, providing a unified physical framework for these observables. Within this solution, the X-ray and gamma-ray emission observed in both low and flaring states originates in the immediate vicinity of the black hole, rather than in a stratified, extended jet. This places strong constraints on the location and efficiency of particle acceleration in the jet formation zone. In particular, a significant fraction of the dissipated energy must be transferred directly to electrons, most likely via magnetic reconnection operating in the highly magnetized plasma near the jet base. These results provide an insight into the microphysics of the jet-launching region, linking horizon-scale plasma conditions to the observed high-energy emission, and constraining the coupling between accretion flow dynamics and jet production in low-luminosity active galactic nuclei.

PKS 0903−57 is a little-studied γ-ray blazar that has recently attracted considerable interest due to the strong flaring episodes observed since 2020 in high energy (HE; 100 MeV ≤ E ≤ 100 GeV) and very high-energy (VHE; 100 GeV ≤ E ≤ 10 TeV) γ-rays (Acharyya et al., HESS Collaboration, 2026). Its nature and properties have not been well determined until recently by Goldoni et al. (2024). The main challenge has been the presence of a nearby star at a distance of 0.67" from the blazar, somewhat hiding it. The work of Goldoni et al. (2024) was carried out as part of the aims of Cherenkov Telescope Array Observatory redshift determination group. We performed spectroscopy of the optical counterpart of the PKS 0903-57 using the Southern African Large Telescope and the Very Large Telescope (VLT), and monitored it photometrically with the Rapid Eye Mount (REM) telescope. Using the VLT observations taken with a narrower slit (0.5'' wide) under subarcsecond seeing (~0.5'') conditions, we were able to isolate the signatures of the blazar from those of the star and firmly measured its redshift to be z = 0.2621 ± 0.0006, thanks to the detection of five narrow optical lines. The detection of a symmetric broad Hα line with full width at half maximum (FWHM) of 4020 ± 30 km/s together with a jet-dominated continuum lead us to classify PKS 0903-57 as a flat-spectrum radio quasar. Finally, we detected with high significance a redshift offset (∼1500 km/s) between the broad line and the host. This is the first time that such an offset has been unequivocally detected in a VHE blazar, possibly pointing to a very peculiar accretion configuration, a merging system, or a recoiling black hole. We have performed further VLT, REM and Swift observations recently (2025) that we are still analyzing and will present preliminary results of the analysis at this conference.

We report a systematic search for remnant radio AGN in a 14.4 square deg. area of the XMM-LSS deep field. These sources, which are devoid of an active core and other compact components, represent the final phase of a radio galaxy's life and they are believed to be rare objects. They can only be observed over a relatively short period of time before the radio lobes with no supply of fresh plasma completely fade away due to radiative and dynamical energy losses. By taking advantage of the high-sensitivity observations from LOFAR at 150 MHz and the excellent resolution of MeerKAT/MIGHTEE DR1 survey at 1.4 GHz, our approach is to adopt multiple selection criteria (e.g. steep spectral signature and low core prominence) instead of a source extraction solely based on visual classification. Incorporating both low and high frequency observations (which respectively trace the old remnant radio lobes and the source compact components) in our selection process helps improve the completeness of our remnant radio galaxy population. From a parent sample of 300 radio sources, we find that at least 8% of the population are classified as remnant candidates. This work demonstrates that by exploiting new observations with unprecedented high sensitivity and high resolution, one should be able to put observational constraints on the duty cycle of radio-loud AGN, and thereby their dynamical evolution.

Understanding how black hole accretion is connected to star formation (SF) is key to constraining galaxy evolution. We investigate this connection in the faint radio sky using MeerKAT MIGHTEE Early Science data in the COSMOS field at 1.28 GHz (median rms ≈ 2 μJy beam⁻¹). Our sample comprises 5223 radio sources with optical and near-infrared counterparts, spanning redshifts up to 𝑧 ≈ 6. Using CIGALE spectral energy distribution fitting, we derive stellar masses (𝑀★), star formation rates (SFRs), infrared luminosities (LIR), and AGN luminosities (LAGN). We classify sources using Eddington-scaled accretion rates combined with SFRs into star-forming low-accretion mode (LAM), passive LAM, star-forming high-accretion mode (HAM), and passive HAM. This framework allows us to directly link accretion mode to host galaxy properties. We find that LAM sources are predominantly hosted by massive, low-SFR galaxies with suppressed specific SFRs (sSFRs), consistent with gas-poor systems. In contrast, HAM sources reside in galaxies with elevated sSFRs, indicating that both SF and AGN activity are fuelled by a common cold-gas supply. This points to a strong coupling between black hole growth and galaxy growth in high-accretion systems.

The hadronic content on relativistic jets in AGN is one of the most relevant questions for this kind of objects, since it impacts significantly the estimates of the jet power, and therefore, its influence on the intra- and inter-galactic medium. In this talk, I will report on a radio to gamma-ray multiwavelength campaign on the blazar BL Lacertae with unprecedented polarimetric coverage from radio to X-ray wavelengths to deep in this problem. The observations caught an extraordinary event on 2023 November 10-18, when the degree of linear polarization of optical synchrotron radiation reached a record value of 47.5%. In stark contrast, the Imaging X-ray Polarimetry Explorer (IXPE) found that the X-ray (Compton scattering or hadron-induced) emission was polarized at less than 7.4% (3sigma confidence level). We argue here that this observational result rules out a hadronic origin of the high energy emission, and strongly favors a leptonic (Compton scattering) origin, thereby breaking the degeneracy between hadronic and leptonic emission models for BL Lacertae and demonstrating the power of multiwavelength polarimetry to address this question. Furthermore, the multiwavelength flux and polarization variability, featuring an extremely prominent rise and decay of the optical polarization degree, is interpreted for the first time by the relaxation of a magnetic "spring" embedded in the newly injected plasma. This suggests that the plasma jet can maintain a predominant toroidal magnetic field component parsecs away from the central engine.

Compact jets in low-luminosity AGN are increasingly recognised as potentially important feedback agents, but direct evidence that they can efficiently couple to the interstellar medium (ISM) of their host galaxies remains scarce. We present JWST/MIRI integral-field spectroscopy and ALMA CO(2-1) observations of ESO 420-G13, a post-starburst galaxy hosting an X-ray-faint LLAGN (L_2-10 keV ~ 10^40 erg/s), and show that a compact jet, nearly invisible in conventional diagnostics, is injecting substantial kinetic power into the surrounding interstellar medium.

The MIRI data reveal a highly collimated coronal gas structure, traced by the [Ne V] and [Ne VI] emission lines and co-spatial with extended Chandra X-ray continuum emission reaching projected distances of about 870 pc from the nucleus. The interaction is strongest about 370 pc north of the nucleus, where a fast ionised gas stream (-1200 to -500 km/s) emerges perpendicular to the jet axis, coincident with a bend in the jet direction. An expanding warm H2 bubble surrounds this stream, with two distinct molecular outflows at its edges: a redshifted component detected in both cold CO(2-1) and warm H2, and a blueshifted outflow detected only in warm H2, that is, a CO-dark outflow. The lack of CO emission in the latter points to shock- and/or cosmic-ray-driven CO dissociation at the jet-ISM interaction front, rendering roughly half of the total outflowing molecular mass (4 x 10^6 Msun) invisible to conventional cold-gas tracers.

Despite the radiatively faint nucleus, we estimate a total outflow kinetic power of ~1.5 x 10^41 erg/s, implying a jet-ISM coupling efficiency of ~3.8%. Roughly 5% of the central molecular reservoir has already been expelled, while the remaining gas is turbulent and warm, indicating an active phase of mechanically driven quenching in this post-starburst host. ESO 420-G13 demonstrates that compact, low-power jets can achieve substantial coupling efficiencies through a cascade of interactions across gas phases, with highly ionised coronal gas mediating the transfer of kinetic energy to the molecular medium. Without spatially-resolved mid-IR diagnostics from JWST/MIRI, neither the jet nor its multiphase impact would have been identified. This system provides a benchmark for understanding how LLAGN, the most numerous yet observationally elusive class of AGN, are able to regulate star formation and drive galaxy evolution.

After about 10 to 100 Myr, the accretion onto the supermassive black hole (SMBH) of active radio galaxies switches off or decreases significantly. But for some RGs a new restarting cycle of nuclear activity is observed after the quiescent phase. Although still an open question, the details on the on/off timing and the cycle frequency are important in getting a full picture of AGN duty cycle and feedback. Studying restarted RGs is one way to have such an insight into RG life cycle. However, the systematic searches and study of these sources are limited. By taking advantage of the MIGHTEE survey data set, we performed a systematic search for restarted radio AGN in the XMM-LSS field. After analysing the parent sample, we report 18 double-double Radio Galaxies (DDRGs) which display double pairs of radio lobes. Additionally, we found 39 sources with a high core prominence (CP > 0.1) and 16 sources with a steep-spectrum core (α < - 0.7). These give a total number of 56 restarted candidates, which represent ~ 8% of our parent sample (17 candidates were selected with two criteria). We have also analysed the spectral index distribution of some sources having double structure in only one side of the core, which were previously attributed to a non-uniform host environment. Combined with a further investigation of the host environment of our subsample of restarted RG, our results will complement our understanding of RG life cycle.

Red quasars exhibit a higher incidence of compact (galaxy-scale or smaller) radio emission than blue quasars, arising from systems near the radio-loud/radio-quiet threshold. This result cannot be fully explained by the standard orientation model, instead favouring red quasars as a distinct phase in a quasar’s lifecycle, possibly an obscured-to-unobscured transition where low-power jets and/or AGN-driven winds drive away gas and dust. I will show there is an excess of steep-slope radio emission ($lpha_{1.4-3 GHz}$ ~-1) from red quasars with compact radio morphologies over 144 MHz, 1.4 GHz, and 3 GHz. This excess steep radio emission signature is not seen in normal blue quasars (radio compact or extended) or red quasars with extended low-frequency radio emission, which instead show a broad range of radio spectral slopes consistent with a range of different physical processes. I will show that the strength of this excess steep-slope radio emission increases with increasing dust extinction, along with an overall increase in the radio-detection fraction. I argue that this excess steep-slope radio emission is due to shocks between quasar-driven winds/jets and the dusty nuclear-host galaxy environment. The majority (~86%) of the dustiest quasars (E(B-V)>0.4) with steep slopes have radio luminosities consistent with the prediction from a wind-shock model with a wind efficiency of 7%. This agrees with the scenario where these compact red quasars are undergoing a “dusty blow-out” phase, where a compact jet and/or AGN-driven winds interact with a dusty ISM, causing shocks, leading to steep spectral slopes and enhanced radio detection rates.

AGN are a vital component to understand galaxy evolution across cosmic time. I will show how we can be sure of this statement from observations of statistical samples of AGN emitting at radio wavelengths, henceforth radio AGN. Firstly, by examining how radio AGN populate their host galaxies, i.e. through their ‘incidence’, I show that there is a stellar mass and radio morphology dependence in how jets are powered in these systems. Interestingly, these differences translate directly to the ways in which these AGN feed back energy to their host galaxies. For example, I find that jet kinetic feedback dominates over any plausible inventory of radiatively-driven feedback for massive galaxies in the local Universe. Importantly, this is mainly as a result of the numerous low-powered compact radio AGN, not the powerful canonical double-lobed (or otherwise complex) radio AGN. Enabled by the sensitive LOFAR survey, this discovery advances the study of compact, low-luminosity AGN and paves the way for deeper exploration with the upcoming Square Kilometre Array to uncover the physical nature of such sources. Additionally, I show that jetted feedback can significantly disrupt the gas kinematics in galaxies and contribute to the heating of this gas, thereby preventing current and future star formation. This unambiguously confirms the crucial role that radio AGN play in the formation and evolution of galaxies and it is the first time that the average jet power of the population of massive galaxies in the local Universe is analysed quantitatively as a function of stellar mass and radio morphology. Therefore, this work provides a clear observational benchmark to calibrate AGN feedback simulations and inform the jet physics going into our models.

Extreme Red Quasars (ERQs) are a rare population of luminous, dust-obscured active galactic nuclei believed to host powerful outflows during a key phase of black hole growth. We investigate their radio properties to explore the connection between quasar-driven winds and jet activity. We construct a sample of ERQs in the XMMLSS and COSMOS fields using optical data from the Sloan Digital Sky Survey and mid-infrared photometry from the Wide-field Infrared Survey Explorer, and cross-match them with deep radio observations from the MIGHTEE Survey.

We calculate the radio luminosities and find that ERQs span log(L_radio) ~ 23–26, consistent with AGN-dominated radio emission. We examine the relation between radio emission and C IV equivalent width and explore a potential connection with radio activity. These results provide constraints on the radio properties of ERQs and their relation to quasar outflows, contributing to our understanding of AGN evolution.

Radio galaxies (RGs) are the primary laboratories for studying relativistic jets, the most energetic phenomena in the Universe, and their subsequent feedback on host galaxy evolution. While classical Fanaroff-Riley (FRI and FRII) sources have historically defined our understanding of these systems, recent high-sensitivity radio and optical surveys in the local Universe (z<0.3) have revealed that the bulk of the population consists of compact radio galaxies, named FR0s. These sources are characterized by a lack of large-scale (>10 kpc) diffuse emission, despite possessing nuclear properties nearly identical to their more powerful FRI cousins. I will present multi-band observations of FR0s, which probe different physical scales of the jet structures and help us to understand their actual capability of launching jets with respect to FRIs. To reconcile their multi-band characteristics, I will propose an accretion-ejection model, featuring mildly-relativistic jets powered by a low-accreting low-spinning black hole. Finally, I will discuss the implications of these compact structures for AGN feedback, questioning whether the modest scales of FR0 jets can still significantly influence the interstellar medium of their host galaxies and their evolution. In the near future, the Square Kilometre Array (SKA) with its high sensitivity and angular resolution will finally determine whether FR0s represent a distinct evolutionary stage or a fundamentally different mode of black hole accretion-ejection in RG population.

Understanding the life cycle of radio emission in active galaxies remains a central challenge in extragalactic astrophysics. Current models of radio source evolution contain degeneracies depending on the prevalence of ‘young but fading’ radio sources. Despite this importance for constraining our understanding, a systematic study of remnants in complete samples of young radio sources has yet to be carried out. To this end, I present an ongoing investigation of compact steep spectrum (CSS) sources from the statistically complete B3-VLA (Very Large Array) CSS sample. This investigation makes use of deep multifrequency VLA, pc-scale Very Long Baseline Array (VLBA), and enhanced Multi Element Remotely Linked Interferometer Network (e-MERLIN) observations . I will present new 4.9 and 8.4 GHz VLBA observations of 10 previously un-imaged sources in the sample, as well as a spectral analysis of these galaxies to characterize them as active, remnant or restarted. I will then compare the results to what has been found in the rest of the sample, including a subsample of 18 CSS radio sources characterized by a steep optically thin spectrum (α ≥ 1.0) and no core detection in earlier studies.  This enables us to determine the occurrence of short-lived radio sources in a statistically robust way for the first time, providing us with crucial information into the evolution of radio galaxies over time.

The mechanisms that fuel and trigger active galactic nuclei (AGN) are central to the observed co-evolution of supermassive black holes and their host galaxies. Galaxy interactions have been proposed as a mechanism for bringing the gas required for AGN triggering and fueling to the last kpc. We study the role of galaxy interactions on AGN activity by analysing a sample of ~1,500 massive AGN selected from the Das et al. (2024) catalogue in the ELAIS-N1 deep field. The AGN are classified as low-excitation radio galaxies (LERGs), high-excitation radio galaxies (HERGs), or radio-quiet AGN (RQ AGN) according to spectral energy distribution fitting and radio-excess criteria. To assess the connection between AGN activity and galaxy interactions, we construct a control sample matched in stellar mass and photometric redshift, selecting three control galaxies for each AGN from the same SWIRE-selected parent population using the SED fits from Das et al.(2024), yielding a total of ~4,700 matched controls. The analysis is restricted to redshifts z < 0.8, where the depth of Hyper Suprime-Cam (HSC) imaging permits reliable identification of tidal features. Galaxies are visually classified using composite gri HSC images, with distinctions made between early- and late-type morphologies and between interacting and non-interacting systems. By comparing the morphological and interaction properties of LERG, HERG, and RQ AGN hosts to those of their matched controls, we assess whether the various radio AGN classes are associated with distinct host galaxy populations and evaluate the significance of recent interactions in triggering AGN activity.

Low-luminosity and compact radioactive galactic nuclei (LL/CR-AGN) represent a critical yet poorly constrained population in the broader framework of galaxy evolution and AGN feedback. Their ambiguous observational signatures often bridging the gap between radio-quiet AGN, young radio sources, and weak jet systems pose challenges for clear classification and physical interpretation. In this contribution, I explore the demographics, defining characteristics, and evolutionary trajectories of LL/CR-AGN through a multi-wavelength and diagnostics-driven perspective. By drawing analogies between radiative recombination processes in condensed matter systems and emission-line diagnostics in astrophysical plasmas, I propose a refined framework for distinguishing between jet-dominated and accretion-dominated low-luminosity sources. Particular emphasis is placed on spectral energy distributions, line ratios, and radio morphology as tools to probe the underlying physical mechanisms. Furthermore, I discuss the role of compact jets in LL/CR-AGN as potential drivers of localized feedback in the interstellar medium, even at sub-kiloparsec scales. The study highlights how recent advances in high-sensitivity radio facilities (e.g., VLBI, MeerKAT, and LOFAR) enable the detection and characterization of these faint systems, offering new insights into their lifecycle from nascent, compact phases to possible fading or intermittently active states. This work aims to contribute to the ongoing effort to establish robust observational criteria and evolutionary models for LL/CR-AGN, ultimately improving our understanding of their role in galaxy evolution and feedback processes across cosmic time.

e-MERGE is a multi-tiered e-MERLIN Legacy programme exploiting the combination of very high sensitivity and spatial resolution to study the formation and evolution of star-forming galaxies and AGN out to redshifts of z~5, providing an obscuration-independent tool for measuring the massive star-formation and AGN activity in the distant Universe. e-MERGE Tier 1 is studying AGN and star-formation in the µJy radio source population in GOODS-N.

The DR-1.5 (Data Release-1.5) wide-field imaging results from e-MERLIN, in combination with the JVLA, and the EVN at 1.5 GHz covering the central 15 arcminutes of the e-MERGE Tier 1 region are in final stages of preparation before release to the consortium. The latest e-MERLIN+JVLA image contains >800 faint radio sources and demonstrates how high-resolution images can disentangle and separate regions of star-formation and AGN activity in the differing µJy radio source populations, deriving the angular size distributions and detailed images for each source type. The emerging heterogeneous ‘AGN-Quiet’ radio population is imaged in detail for the first time, indicating that for many such systems the bulk of the radio emission originates from star-formation processes. The I.5GHz deep

combination image covering the central 15 arcminutes of GOODS-N optimises both angular resolution and sensitivity with a restored clean beam of ~270mas and sensitivity at the field centre of 1.2µJy/bm (1 sigma). The combination image is fully corrected for the contiguous primary beam responses across the heterogenous array, which is comprised of JVLA 25m, and e-MERLIN 25m, 32m (Cambridge) and 76m (Lovell) antennas. The outer part of the image lies beyond the 10-arcminute diameter primary beam response of the Lovell antenna with the antenna weighting approaching zero zero at the edges of the 15’x15’ field resulting in the sensitivity dropping to1.9µJy/bm at the far corners of the field.

My presentation will describe our investigation into properties of the high- and low-luminosity AGN systems and the galactic-scale extended radio emission radio associated with these sources. In addition the presentation will include investigation into the radio emission associated with star-forming galaxies which dominate the radio source population, the more luminous of which often display nuclear starburst emission which may also contain faint emission from embedded AGN. Finally I will describe the detailed properties of the distant (z=1.2653) highly luminous wide-angled tail radio source which lies within the

radio field.

The LOFAR Two-Metre Sky Survey (LoTSS) Deep Field Survey provides high-sensitivity radio catalogues over tens of square degrees with exquisite-quality multi-wavelength data, including extensive spectroscopic data now provided by DESI. This provides a remarkable resource to understand the triggering, evolution and feedback effects of low-power radio-AGN across cosmic time. I will discuss the classification of these radio sources, and explore the cosmic evolution of the prevalence of low-power radio-AGN activity across the galaxy population. I also compare the energetic impact of radio jets against winds, at a population level, to explore the dominant mechanisms for AGN feedback. The results have implications for radio-AGN fuelling and the radio-AGN feedback cycle.

Quasi-periodic eruption (QPE) host galaxies offer a unique window into supermassive black hole (SMBH) accretion, yet their connection to the broader active galactic nuclei (AGN) population remains unclear. Intriguingly, several confirmed QPE nuclei exhibit extended emission-line regions (EELRs) whose ionization requirements exceed the current luminosities of their nuclei, suggesting faded AGN hosts. On the other hand, growing observational evidence suggests that QPEs may be preceded by tidal disruption events (TDEs). The QPE discovery source, GSN069, shows compact radio emission consistent with an outflow associated with its current long-term X-ray TDE activity, although whether its EELR reflects a previous enhanced TDE rate or a past AGN phase remains unknown. Distinguishing between these scenarios helps to constrain accretion-state transitions and the duty cycle of compact nuclear activity.

I will discuss novel optical imaging polarimetry and spectropolarimetry observations of GSN069 using VLT/FORS2. We detected a radially increasing polarization pattern consistent with scattered light from a switched-off nucleus. The polarization angle defines a preferred axis aligned with elongated [O III], [N II], and Hα emission, revealing a EELR consistent with relic polarization cones and a past torus-like structure. In other words, these polarization echoes favour a faded AGN as the origin of the EELR, rather than a past episode of TDE activity, and demonstrate polarization as a tool capable of unveiling how SMBH accretion shapes its host galaxies.

The Fundamental Reference AGN Monitoring Experiment (FRAMEx) is a volume-limited

(<40 Mpc) survey studying AGN accretion physics as a function of time. The hard X-ray

selected sample probed parsec physical scales with the Very Long Baseline Array at 6 GHz,

but only 12 out of 25 sources were detected, despite expectations. A uniform set of follow-

up broadband observations of the FRAMEx sample were subsequently observed and

detected with the Very Large Array (VLA), indicating that extranuclear radio emission is

produced at physical scales between about 1-200 parsec in the region surrouding the

supermassive black hole. I will present results from these VLA observations using uniform

analysis. I find that the radio emission is likely too luminous for star formation alone and

that AGN winds are a viable mechanism of radio emission produced in situ from an

energetics perspective.

“What sets radio morphology?” remains one of the central open questions for jetted AGN. Proposed drivers include host environment, central engine properties, and source age. Answering this question requires a multi-scale framework that connects the injection and collimation of initially conical outflows with the kiloparsec-scale radio morphologies and multi-modal feedback signatures they produce in complex environments.

In this talk I will present results from the Cosmological Double Radio AGN (CosmoDRAGoN) simulations (Yates-Jones+23), a 22M CPU hour suite of relativistic magnetohydrodynamic jets evolved in environments drawn from cosmological galaxy formation simulations. By varying jet power, opening angle, injection velocity, and environment, these simulations reproduce a range of radio morphologies generated by jet-environment interactions in dynamic, non-idealised systems. We track the evolution of the radiating particle populations and generate synthetic radio and X-ray observables, including spatially resolved spectra and polarimetric diagnostics, linking the underlying dynamics directly with telescope observables.

I will show that jet-environment coupling efficiency depends strongly on both environment density and source power, with lower-power jets coupling more efficiently and feedback enhanced in group environments. I will also discuss how the balance between shocks, turbulence, and gas redistribution evolves over the duty cycle from active to remnant and restarted phases, and show that remnant lobes can continue to drive shocks after jet activity has ceased (Stewart+25). These results provide a physically motivated framework for interpreting radio morphology across scales, benchmarking multi-frequency observations, and quantifying jet feedback.

Many key aspects of how Active Galactic Nuclei (AGN) feedback, powered by supermassive black holes, shapes the circumgalactic and intracluster media of galaxy groups and clusters remain uncertain. Likewise, the back-reaction of accretion flows and the formation of clumpy cold gas triggered by feedback are poorly understood. This work, embedded in the BlackHoleWeather (BHW) project, aims to address all major outstanding questions across the full range of relevant scales, to build a unified, self-consistent, and bottom-up description of AGNs. We are developing state-of-the-art models of jet and winds feedback, black hole spin, turbulence driving, and chemical evolution from the BH horizon scale up to cluster sizes. Via the GPU-accelerated AthenaPK code, we gain in resolution and physical fidelity, by resolving magnetic fields, powerful jets, and multiphase cold gas at unprecedented detail. We present here a comprehensive picture of black hole feeding and feedback that connects processes across scales and phases, testing theoretical predictions and guiding future observations.

Learning from the small to understand the large: a comparison of Protostellar outflows with AGN jets

Francesca Bacciotti^1, Brunella Nisini^2 & Francesca Panessa^3

1 INAF - Osservatorio Astrofisico di Arcetri (Florence)

2 INAF - Osservatorio Astronomico di Roma

3 INAF - Istituto di Astrofisica e Planetologia Spaziali (Rome)

Jets from active galactic nuclei (AGNs) are among the most powerful manifestations of astrophysical outflows, yet many of the key physical processes governing their origin and propagation remain unclear. In this context, protostellar jets — three orders of magnitude smaller in scale — offer a unique and accessible laboratory for investigating the fundamental physics of jet formation and propagation. Protostellar jets and their associated molecular winds provide a direct insight into magnetohydrodynamic launch mechanisms, angular momentum extraction, shock structures and jet-environment feedback under conditions that are more easily observable than those of AGN systems.

In recent years, several groups, including the Italian JEDI (JEts and Disks @INAF) collaboration, have been actively working to define the physics of protostellar outflows, combining detailed theoretical studies, high performance numerical modeling, and high-angular-resolution observations with the best facilities currently available, such as ALMA and JWST. Recent advances have fostered synergies between communities studying jets in different astrophysical contexts, with dedicated meetings and collaborations, like the Italian GIGA (Gruppo Italiano Getti Astrofisici), that adopt an interdisciplinary approach. These initial links have already highlighted how bridging the gap with a comparative, multi-scale approach can enrich our understanding of the physics of both stellar and AGN jets and strengthen the broader paradigm of accretion-driven outflows throughout the universe.

I present a 350-hour JVLA campaign obtaining deep, highly resolved, and thermal-noise limited maps of 3CRR: a foundational new legacy transforming our knowledge on the jets of radio galaxies. The resulting total intensity, polarization, and spectral index maps (which will be provided to the community) have revealed new jet structures never-before seen on all scales, while shedding light on the interplay of relativistic particle acceleration, magnetohydrodynamic flows, and interactions with the surrounding medium. Jets are clearly shaped by dynamic environments, and in some systems, by Lens-Thirring precession of the accretion disk. Unification of these unprecedented JVLA maps of 3CRR with LOFAR, and with IR, optical, and X-ray maps at matched resolution gives us the power to address the composition of jets through truly broad-band modelling for the first time -- we address the long-standing enigma of X-ray jets which have fuelled theories on exotic particle physics in these systems. At the same time, we have also obtained insights into the mechanisms behind feedback on larger scales, showing that the true lobe structure, filled with dynamic synchrotron filaments and threads, are long-lived through slow re-energization by magnetic structures that are compressed by backflows, as predicted by numerical simulations. I also show insights into cosmic evolution through high-z 3C objects, detecting the lowest-energy lobes for the first time in inverse-Compton Ghosts. These results will engage the community with new theories on jet physics, stimulating a wealth of collaborative work.

Blazars offer a uniquely powerful laboratory to simultaneously investigate jet physics, the properties of the high-redshift AGN population, and cosmological parameters. In this talk, I present a multi-scale/multi-frequency view of blazars as “golden objects,” focusing on recent Very Long Baseline Interferometry (VLBI) results spanning meter to millimeter wavelengths. On the one hand, high-redshift blazars (z>6) observed with VLBI across multiple scales and frequencies provide direct access to the earliest phases of jet activity and supermassive black hole growth. On the other hand, strongly lensed blazars offer an exceptional opportunity to probe both jet physics, linking low- and high-energy emission mechanisms, and cosmology.

By combining lensed and non-lensed high-redshift blazars within a unified VLBI framework, I highlight how these sources can bridge physical scales (from sub-parsec jet launching regions to cosmological distances) and observational regimes (from low-frequency synchrotron emission to high-energy gamma rays). This framework highlights how blazars can be leveraged to connect jet physics and cosmology, and serves as a testbed to develop and optimize observing strategies for upcoming facilities, including the Square Kilometre Array and SKA-VLBI, in synergy with next-generation multi-messenger observations.

The morphology of extragalactic radio sources has traditionally been classified into two types based on the relative positions of high and low‑brightness regions and radio luminosity. Modern radio interferometers have advanced this field through high sensitivity and angular resolution. We revisit the Fanaroff and Riley classification (Fanaroff & Riley, 1974) using deep MeerKAT and uGMRT observations of 14 radio galaxies. Our morphological and spectral analysis reveals complex jets, lobes, and hotspots, as well as spectral breaks indicating radiative ageing (∼40–242 Myr), and interaction with the external medium. While the sample broadly confirms the classical FR classification as a useful first-order scheme, the substructures within the radio emission highlight the need for models that incorporate environmental complexity and episodic jet activity. We will present a comprehensive interpretation of the radio galaxy sample.

Giant radio galaxies (GRGs) are the most extreme laboratories of AGN jet evolution, yet the drivers of their megaparsec-scale growth remain unresolved. We present a high-fidelity study of seven serendipitous GRGs from the MeerKAT Galaxy Cluster Legacy Survey, exploiting MeerKAT’s sensitivity to map spectral ageing across structures spanning 0.85–2.19 Mpc.

Spatially resolved spectral index analysis reveals clear ageing gradients—steepened lobes contrasted with rejuvenated cores—yielding spectral ages of 23–93 Myr. The sample displays striking morphological diversity (FRI, FRII, and Z-shaped systems), with newly identified large-scale kink features indicating strong jet–environment coupling even in low-density regimes.

We report the discovery of a new GRG (MKT J234937.84-263015) and uncover compelling evidence for episodic jet activity and plasma back-flow in MKT J002659.83-121831.3. These results reinforce the role of duty cycle modulation and environmental interaction in shaping GRG evolution, positioning MeerKAT as a key instrument for constraining the life cycles and feedback impact of radio-loud AGN.

AGN jets are fundamental drivers of galaxy evolution, injecting kinetic energy into their environments. The large-scale morphology and spectral properties of these radio galaxies arise from complex particle acceleration, energy loss, and absorption processes. While the shape of the synchrotron spectrum encodes the plasma's energetic history, understanding the physics of particle acceleration and duty cycles has historically been limited by a lack of well-resolved observations at ultra-low frequencies (<100 MHz), where the oldest cosmic ray electron populations are traced. This study presents the first comprehensive multi-frequency analysis of bright, extended radio galaxies down to 58 MHz using LOFAR. We investigate electron acceleration mechanisms by accurately measuring the low-frequency spectral shape and constrain the injection index for a sample of 22 jetted radio galaxies from the 3CRR catalogue. Using these low-frequency data, we determine where in the radio galaxy jets plasma is injected and how steep the injected spectrum is. We also present ultra-low-frequency spectral index maps for the sample. For FR I galaxies, spectral indices range from ~0.5 near the core (consistent with first-order Fermi acceleration) to >1.0 in the lobes. For FR II galaxies, hotspots exhibit steep low-frequency injection spectra of 0.5–0.9. This study demonstrates how future facilities operating at similar frequencies, particularly SKA-Low, will advance our understanding of the factors that determine galaxy morphology.

We will present the discovery and analysis of "Inkathazo" - a 1.3 Mpc sized giant radio galaxy at the centre of a cluster. Inkathazo was discovered in MeerKAT observations of the COSMOS field and is, rather unusually, hosted by a brightest cluster galaxy (BCG) at z~0.1. We have performed a spatially-resolved spectral age analysis of this GRG using MIGHTEE L-band and new UHF-band observations. We will show that Inkathazo does not follow expected electron ageing models, possibly due to electron re-acceleration via interactions with the intracluster medium (ICM). Hence the nickname "Inkathazo", which has a meaning akin to "trouble" in the African Zulu language. Additionally, one jet of Inkathazo is bent almost at a 90 degree angle, making it a peculiar radio galaxy. We have performed relativistic hydrodynamical simulations of this jet, and will show that it is possible to reproduce this morphology purely via cluster winds without the need for magnetic instabilities. This hints at a coupling between the ICM and the jet.

Brightest cluster galaxies (BCGs) are among the most luminous and massive galaxies in the current epoch that host supermassive black holes (SMBHs) with powerful radio jets. They are expected to contribute to the cosmic-ray population in galaxy clusters and to emit non-thermal radiation detectable by the current γ-ray telescopes. However, past research on BCGs with the Fermi-LAT γ-ray space telescope produced only upper limits, with a few exceptions. A fourfold increase in Fermi-LAT data compared to earlier studies allows us to analyse the spectral and temporal variability of a sample of ten 4FGL-DR4 catalogued BCGs individually. We present the γ-ray light curves and spectral energy distributions of the ten BCGs, including the well-known radio galaxies M 87, NGC 1275, PKS 0625-354 and 3C 264. These results further our understanding of the interplay between the galaxy cluster environment and the SMBHs hosted by the largest and brightest cluster galaxies.

AGN jets radiate radio synchrotron emission displaying a wide range of morphologies. At the same time, they provide heat to prevent cooling flows in cool-core galaxy clusters. We produce mock radio observations of jets in a self-regulating cool-core galaxy cluster. We employ magneto-hydrodynamical simulations of an idealized Perseus-like galaxy cluster, in which accretion-powered low-density jets accelerate cosmic ray protons and electrons by means of a sub-grid model. Cosmic ray electron spectra are spatially and temporally evolved along Lagrangian tracer trajectories using the Fokker-Planck solver Crest to produce non-thermal emission. The resulting synthetic radio observations display realistic Faranoff-Riley I and disturbed lobe morphologies, with radio luminosities and surface brightness levels on par with observations. The cool-core cluster self-regulates for a duration of 2 Gyr, over which the jets inflate multiple generations of lobes filled with cosmic rays and magnetic fields, isotropically distributed around the central supermassive black hole. This can be explained by cold gas structures deflecting the low-density jets, leading to complex radio-emitting lobe structures despite synthetic observations made along the jet launching direction, i.e. in a blazar configuration. Spatially and temporally evolved cosmic ray electron spectra allow us to determine electron ages and precisely how young and old electrons contribute to the observed emission globally and locally. These simulations, in addition to providing a window into AGN jet feedback through radio diagnostics, display a variety of radio phenomena such as restarted and remnant radio galaxies due to the time-varying nature of the jet luminosity.

We test how three cosmological hydrodynamical simulations: Magneticum, IllustrisTNG, and SIMBA reproduce galaxy and hot halo gas properties in the local Universe using constraints from Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. We analyse the evolutionary paths of multi-wavelength AGN hosts across the SFR–M* plane and quantify environmental effects using halo masses from the SDSS DR4 Galaxy Group Catalogue. Observationally, AGN activity follows the SFR axis, whereas simulations show stronger stellar-mass trends. No model simultaneously reproduces both galaxy demographics and halo gas properties: Magneticum and SIMBA perform well in the gas sector but over-quench galaxies, while IllustrisTNG more faithfully reproduces galaxy properties at the cost of excess halo gas. This tension indicates that current AGN feedback models remain incomplete.