Conveners
Galaxy Evolution & AGN
- Chair: Enrichetta Iodice
Galaxy Evolution & AGN
- Chair: Viviana Casasola
Galaxy Evolution & AGN
- Chair: Paolo Serra
Active Galactic Nuclei (AGN) are key drivers of galaxy evolution, triggered by cold gas accreting onto a super-massive black hole. However, the processes regulating this gas accretion (feeding) and how AGN alter the interstellar medium to affect star formation (feedback) remain poorly understood. A major observational challenge is the vast range of spatial scales involved: AGN fuelling and...
Nearby galaxies offer an invaluable bridge between detailed, cloud-scale observations within the Milky Way and the integrated view of star formation in distant systems.
Thanks to ALMA, molecular gas structures, where star formation happens, can now be studied at sub-parsec scales in local galaxies.
Meanwhile, LOFAR (the Low‑Frequency Array) has improved our understanding at the other end of...
Galaxies undergo diverse evolutionary processes depending on their environment, often leaving clear imprints in their neutral hydrogen (HI) content and morphology. In cluster environments, HI tails are common and serve as indicators of gas removal through tidal and/or hydrodynamical interactions. Yet, the dominant mechanisms responsible for these features remain debated. The Fornax cluster, a...
The interstellar medium (ISM) regulates star formation, a key driver of galaxy evolution. Understanding how atomic and molecular gas, dust, and metals interact is crucial for deciphering these processes.
I present high-resolution MeerKAT HI observations of NGC 1365, the Great Barred Spiral Galaxy in the Fornax cluster, and compare them with ALMA molecular gas, DustPedia dust, and gas-phase...
HI studies have been longly limited to z<0.4 due to limited sensitivity of interferometric facilities, not deep enough to compensate for the intrinsic faintness of the 21-cm line. A computationally cost-effective alternative is stacking, which allows us to determine average HI properties of samples of galaxies beyond the detection limit. Pioneering works with MeerKAT, ASKAP, jVLA, and uGMRT...
In this talk I’ll present the most recent update of the state-of-the-art phenomenological simulation SPRITZ to include neutral hydrogen (HI). This update has been performed using the empirical stellar mass - HI mass relation and validate against available observations. SPRITZ already correctly reproduce the stellar mass function at different redshifts and the molecular gas mass density and...
The accretion-ejection mechanism acting in Active Galactic Nuclei (AGN) is one of the main astrophysical open issues, being connected to the role of AGN feedback in galaxy formation evolution studies. Radio Quiet AGN constitutes the large majority of radio sources in the sky. The absence of luminous jets allows us to investigate their radio emission originating from a wide range of possible...
Low-power radio active galactic nuclei (AGN) with radio luminosities below 10$^{23}$ W Hz$^{-1}$ represent a numerically dominant but still poorly understood population, crucial for unveiling the full impact of radio-mode feedback on galaxy evolution. Unlike classical FR I/II sources, these faint AGN often lack prominent extended jets and lobes, making them elusive in current surveys and...
Understanding the interplay between active galactic nuclei (AGN) and star-formation activity in galaxies stems from our ability to disentangle and gauge the emission arising from both phenomena. I will present the preliminary results obtained from "AGN-sCAN", a high-resolution (0.01 arcsec) radio survey carried our with the Very Long Baseline Array (VLBA) in the COSMOS field. The combination...
The Square Kilometre Array (SKA) will open a new observational window on the radio-faint sky. The large sky coverage and the high sensitivity of this facility will enable us to reconstruct, for the first time, the distribution of the sub-µJy radio sources. The milliarcsecond-scale spatial resolution delivered by the SKA-VLBI project (SKA - phase2) will also allow to detect compact radio cores...
Hyper-luminous QSOs (HyLQSOs, i.e. $L_{bol}>10^{47}$ erg/s), are powered by the most massive, highly-accreting supermassive black holes (SMBHs, i.e. $M_{BH} >$ 10$^{9}$ $M_{\odot}$). Following the nowadays consensus view on SMBH-host galaxy co-evolution, the huge amount of energy released by highly-accreting SMBHs in HyLQSOs is able to strongly affect the evolution of the host galaxy by...
We investigate the radio and multi-wavelength properties of 165 blazars from the Fermi-LAT 4FGL catalogue, cross-matched with the ASKAP FLASH continuum survey. The sample includes FSRQs, BL Lacs and blazar candidates of uncertain type, with complementary coverage from RACS, GLEAM-X, AT20G, and ALMACAL, and archival optical/IR and X-ray data.
Radio spectral energy distributions were...
We present a joint analysis of the radio and optical morphological properties of LOFAR sources in the Euclid Deep Field North. Radio sources have been separated into AGN and star-forming galaxies and further subdivided according to their radio appearance (e.g. whether point-like or extended/complex). This information has then been complemented with Euclid/VIS images which provide a snapshot of...
I will summarise status and ongoing developments of a project investigating galaxy population properties in massive clusters at z~1.5 and progenitors about 1-1.5 Gyr earlier, in the context of the transition from the proto-cluster to established cluster regimes. In particular, I will present deep MeerKAT observations for both the Spiderweb protocluster and a complete sample of massive (a few...
Star-forming galaxies (SFGs) are the dominant population in the faint radio sky, corresponding to flux densities < 0.1 mJy. Understanding star formation processes across cosmic time requires a panchromatic approach. Semi-empirical models, relying on minimal assumptions and exploiting empirical relations between galaxy properties, are particularly powerful in this context, enabling us to take...
Recent extragalactic surveys with the JWST have uncovered a population of compact, extremely red sources at high redshift called Little Red Dots (LRDs) which are characterised by V-shaped continuum with a vertex at around 4000 Å. Interestingly, studies have shown that their number density decreases towards lower redshifts (<4). Two competing ideas suggest that LRDs may be extremely...
The evolutionary stage of a powerful radio source originated by an AGN is thought to be related to its linear size. However, the fraction of young radio sources in flux density-limited samples is much larger than what is expected from the number counts of large radio sources, suggesting the existence of short-lived objects and/or intermittency of jet activity. Determining the incidence of...
Relativistic jets from active galactic nuclei (AGN) inject vast amounts of cosmic rays and magnetic fields into their surroundings—but what happens when the jets switch off? The remnant plasma they leave behind holds crucial clues to the life cycle of radio galaxies and the non-thermal properties of the intergalactic medium, yet it has long remained elusive. In recent years, SKA precursors and...
The HI mass function is a crucial tool to understand the evolution of the HI content in galaxies over cosmic times, and hence, to constrain both the baryon cycle in galaxy evolution and the reionization history of the Universe. However, the intrinsic faintness of the 21cm line has made it hitherto prohibitive to measure it directly from HI galaxy surveys beyond the nearby Universe. In this...
LOFAR has proved to be one on the most successful SKA pathfinder in the
Northern hemisphere opening up a poorly investigated radio window
providing observations at 144MHz with unprecedented sensitivity and resolution with the addition of the International Stations.
The Euclid Deep Field North (EDFN), located at RA=269.73 deg and
Dec=+66.02 deg in the North Ecliptic Pole (NEP) region, is...
