HII regions are fundamental units of the matter cycle in galaxies and their optical emission serves as the main lens through which we study star formation and chemical enrichment across the Universe. They are the sites where ionising radiation and stellar winds have their main impact, turbulence is injected, and heavy elements are dispersed into the interstellar medium. The sizes and internal...
In this talk I will present results from the FIRE cosmological zoom-in simulations exploring the (un)changing properties of the ISM through cosmic time, from redshift three to zero. I will highlight how on (sub)kiloparsec scales, several important properties of the ISM do not change as the galaxies grow and evolve from dispersion-supported, star-bursting objects to rotation-supported, smoothly...
Nearby galaxies observed at high spatial resolution with JWST, ALMA, and MUSE allow us to address fundamental questions related to the influence of young stars on their surrounding interstellar medium (ISM), from cloud to galactic scales: How far can ionizing photons travel, and what physical mechanisms favor their escape from HII regions? How do such processes shape the ISM and influence...
The interstellar and circumgalactic media are the two important reservoirs that fuel star formation in galaxies. Their highly turbulent internal dynamics are shaped by feedback processes such as supernova (SN) explosions and subsequently accelerated cosmic rays (CRs). With recent advances in the hydrodynamical modeling of the interactions between CRs, magnetic fields, and their environment, it...
Modern computational advancements have brought about a resurgence in the consideration of cosmic-rays for driving galactic outflows. This is particularly important in normal galaxies whose thermal and radiation pressure alone is insufficient to expel gas and dust from the disk. Synchrotron radio emission is one of the only—and by far the most accessible—direct tracers of cosmic-rays in...
Despite the many successes of cosmological galaxy formation and evolution simulations, they commonly implement baryonic feedback in a phenomenological manner by calibrating “boosting” parameters, which somewhat diminishes their predictive power and restricts their usefulness in interpreting observational data. An alternative approach is to improve the modelling of feedback processes from first...
Thanks to the unprecedented sensitivity of JWST/NIRSpec, we are now able to study neutral atomic outflows in massive galaxies at high redshift. By detecting optical resonant lines such as Na D and Ca K, which have long been inaccessible from the ground, we have characterized the velocity and mass outflow rate of the neutral phase for a representative sample of galaxies at z~2, finding that...
Feedback in the form of outflows is believed to be a key ingredient in galaxy evolution. In cosmic noon galaxies, outflows have mainly been detected - and extensively studied - in the ionised gas phase. However, it has been surmised that a large fraction of outflowing mass may be in molecular gas form, as suggested by results of luminous but rare AGNs and quasars. To gain insights into the...
Massive, large-scale galactic outflows are well known to be important to galaxy evolution. They shape the high-mass end of the mass function, enriching the circumgalactic and intergalactic medium, preventing the cooling catastrophe in galaxy clusters and so on. They also presumably establish the observed correlations between supermassive black holes and their host galaxies, such as the M-sigma...
Relativistic jets emanating from active galactic nuclei (AGNs) play a pivotal role as a feedback mechanism in the Universe, and the cosmic rays (CRs) carried by AGN jets can have profound influence on galaxy properties and the circumgalactic medium. Consequently, self-consistent modeling of CR propagation, spectral evolution, and emission mechanisms is imperative for understanding the thermal...
In this talk, I will show how the study of AGN incidence distributions is a powerful tool to understand the global energetics of AGN feedback. We use the complete, spectroscopic GAMA09 survey (z<0.4) to measure the fraction of galaxies hosting radio and X-ray AGN, defined using LOFAR and eROSITA data, as functions of mass-scaled power indicators. We recover the previously found mass-invariant...
The profound influence of supermassive black holes (SMBHs) on their host galaxies includes altering the orbits of stars, regulating star formation, modifying gas distribution, to name a few. To understand these processes we need to first understand how SMBHs grow through gas accretion and their associated feedback into the surrounding environment. These factors remain a current crucial...
The CGM and IGM contain fuel for future star formation and a record of past feedback. They are uniquely sensitive to the physics of baryonic flows. Diffuse, ionized plasmas such as the CGM are expected to be turbulent, because of the expected high Reynolds number. The presence and magnitude of this turbulence have profound implications for the sources that drive the thermal and dynamic...
Massive stars in star-forming regions inject huge amounts of energy and momentum into the ISM, producing ubiquitous superbubbles, turbulent gas motions and outflows. The coupling efficiency of mechanical stellar feedback and its dependence on metallicity remains uncertain in simulations. High angular resolution observations with integral-field spectrographs (e.g., MUSE), combined with the...
The small-scale processes of star formation and feedback are tightly linked to galaxy evolution through a multi-scale matter cycle. During this cycle, stars form from the interstellar medium (ISM), and reshape it by injecting energy, momentum and metals, completing a feedback loop. The duration and the efficiency of the successive stages of this cycle vary across and within galaxies, but the...
Galactic-scale outflows, driven by supernova feedback in Milky Way-mass galaxies, play a crucial role in transporting metals from the disc to the circumgalactic medium (CGM). The distribution of these metals across different temperature phases within multiphase outflows is key to understanding CGM enrichment, as metal loading varies between phases. High-resolution, idealized simulations of...
Starburst regions in a galaxy are the primary source of stellar-driven winds, which contribute to regulating the star-formation cycle. We investigate the properties of the gas distribution, kinematics, and ionization conditions of the near-side outflow along eight sightlines that reside in the 30 Doradus region of the LMC using UV absorption-line and H I 21-cm radio emission-line observations....
I present the first statistical study of circumgalactic outflows mapped through MUSE observations of Mg II 2796, 2803 emission, revealing extended halos that span several tens of kiloparsecs from their host galaxies. These observations herald a significant advance for deciphering the role of feedback processes in regulating galaxy evolution. Our analysis combines deep MUSE observations with an...
Galaxies interact with their surrounding circumgalactic medium (CGM) through complex feedback mechanisms that regulate their evolution. The CGM, like other astrophysical media, is a turbulent, magnetised environment where mixing processes and radiative cooling drive the formation of multiphase gas. Understanding this multiphase nature is crucial for understanding the baryon cycle, yet...
Studying the circumgalactic medium (CGM) is a challenge, particularly at the key epoch prior to Cosmic Noon ($z > 2$), where galaxies samples remain very small. However, there is an abundance of Lyman-alpha forest data that contain a wealth of information about the conditions present in this medium.
Morrison et al (2024) showed that a new class of CGM absorption should be studied: Strong...
It is generally believed that the magnetic dynamo in galaxies is a key factor in amplifying small cosmic seed fields to the strengths observed today, both within galaxies and in the CGM/IGM. While simulations with MHD have generally shown modest changes of the overall star formation, magnetic fields are a key factor in the propagation of cosmic rays and their effect on the cloud-scale physics...
Large-scale cosmological simulations of galaxies like IllustrisTNG have been enormously useful at providing quantitative insights on galaxy evolution, especially after the end of Reionization. However, their limited numerical resolution and, crucially, their crude implementations of the physics of star formation, of stellar feedback, of cold gas and of the interstellar medium makes them less...
Directly observing the first quenched galaxies and understanding the feedback mechanisms that shaped their star-formation histories (SFHs), quenching and baryon cycles is crucial for constraining galaxy formation models. Prior to JWST, quenched galaxies were only identified up to z < 4, and high-redshift (z > 3) quenched galaxies were exclusively massive (M⋆ > 10^10 M⊙). JWST has now pushed...
Various solutions have been proposed to solve the high-redshift `bright galaxy problem', such as more efficient star formation, more bursty star formation, and top heavy initial mass functions. While equally interesting, each scenario must also differ in how these stellar populations couple to the interstellar medium (ISM) through stellar feedback. In this talk, I will present first results...
There is ample empirical evidence that galaxies’ star formation efficiency is nearly universal even across a wide range of galactic environments and metallicities. We use a suite of high-resolution hydrodynamics simulations of isolated galaxies at different metallicities to study how the cold, dense interstellar medium and star formation rate vary as a function of chemistry, ionizing radiation...
Many cosmological simulations typically rely on highly mass loaded, ejective winds, particularly for low mass galaxies, to regulate star formation. Recent hints from observations, analytical theory, and idealised simulations have pointed towards lower mass loadings, and a more preventative form of feedback. Using the Arkenstone winds framework, for the first time we model the impact of low...
Feedback from active galactic nuclei (AGN) plays an essential role in current models of galaxy formation, yet the details of this process remain extremely uncertain. I will describe our work combining numerical simulations with microwave and X-ray observations to better constrain this process. Our team has conducted a series of simulations covering a broad range of feedback properties. At...
We present initial results from extremely well-resolved 3D magnetohydrodynamical simulations of idealized galaxy clusters, conducted using the AthenaPK code on the Frontier exascale supercomputer. These simulations explore the self-regulation of galaxy groups and cool-core clusters by cold gas-triggered active galactic nucleus (AGN) feedback incorporating magnetized kinetic jets. Our...
Since JWST began providing breakthrough results in July 2022, our understanding of early galaxy formation has been challenged. While HST enabled us to observe galaxies out to z ~ 10, JWST has pushed this boundary further, revealing an unexpected overabundance of massive galaxies at z > 10. This discovery challenges theoretical models, implying rapid evolution of dark matter halos during this...
Lyman-alpha (Lyα) emission serves as a valuable probe of gas kinematics in and around galaxies. Observations of high-redshift galaxies frequently exhibit distinctive Lyα spectral features, often indicative of optically thick, neutral galactic outflows. However, the extent to which galaxy formation simulations can reproduce these observations remains an open question. We investigate this issue...
The COLIBRE model of galaxy formation is the new flagship suite of simulations of the Virgo consortium. It builds upon years of development by a big team and is a substantial leap forward compared to the previous (and existing) generation of models. In brief, the key improvements are: (1) a modelling of the cold ISM phase, (2) a multi-grain, multi-size fully-coupled dust model, (3) the...
Simulations of galaxy formation are mostly unable to resolve the energy-conserving phase of individual supernova events, having to resort to subgrid models to distribute the energy and momentum resulting from stellar feedback. However, the properties of these simulated galaxies, including the morphology, stellar mass formed and the burstiness of the star formation history, are highly sensitive...
Despite recent discoveries of quasar feedback in action through outflows and jets, the amount of energy that the active nucleus is capable of injecting into the extended medium of the host galaxy remains unknown. The most mysterious component of quasar feedback is the lowest density, hot volume-filling gas. Though there are tentative detections of this component via its thermal...
In this talk, I will present the "Beyond" simulation project, a series of hydrodynamical simulations conducted using the AREPO code. I introduce a novel, physically motivated, approach to SMBH feedback, dynamically adjusting feedback efficiency and implementation based on the evolving properties of SMBHs.
The results reveal how this feedback mechanism shapes the properties of galaxies and...
Outflows in galaxies play a crucial role in AGN feedback by transporting mass and energy from the nucleus to larger scales through winds and jets, as observed across multiple wavelengths. Theoretical models suggest that quasar feedback originates from sub-relativistic Ultra Fast Outflows (UFOs) ($\sim$10$^4$ km/s) launched at accretion disk scales, which interact with the ISM, slowing down and...
Recent results from Morrison et al (2024) have demonstrated that strong-blended Lyman-alpha (SBLA) systems are a rich resource for exploring the properties of the circumgalactic medium (CGM) at z > 2. In SDSS they reveal the global properties of 10^4 CGM systems showing cold clumps of super-solar gas on sub-parsec scales with exquisite precision.
I will introduce SBLAs to the uninitiated...
Large volume cosmological simulations have difficulties in modelling the multi-phase nature of the interstellar medium. Warm and cold clouds cannot be spatially resolved, leading to numerical overcooling if left unaltered. To avoid numerical fragmentation and excessive star formation, large scale simulations usually employ an effective equation of state along with an empirical star formation...
In light of recent high-redshift observations from JWST, it is imperative for large-volume cosmological simulations to provide accurate predictions on galaxy formation in the early Universe. However, low-resolution simulations such as IllustrisTNG or EAGLE have limited validity in this regime, not least because they have to rely on ISM sub-grid modeling that does not entirely reflect our...
Mergers can trigger AGN activity and starburst events, making them ideal environments for studying outflows and the feedback effects of AGN and star formation.
The galaxy MCG-03-34-43 is an advanced merger where recent HST and Chandra observations have revealed a dual AGN system at its center, with a separation of less than 100 pc.
Using VLT/ERIS near-infrared (NIR) integral field...
The most rapid and energetic SMBH growth in the Universe has occurred in luminous quasi-stellar objects (QSOs), the most powerful class of AGN, making them the perfect laboratories for observing galaxy–SMBH evolution. When we have an unobscured view of the accretion disc, which peaks in the UV, QSOs display very blue UV–optical colours. However, we have recently discovered a hidden,...
Today, large scale galaxy simulations take advantage of magneto-hydrodynamics, relying on a continuum approximation of interstellar gas. This, in turn, relies on the assumption that the mean free path is well below the resolution of the simulation. This is true for many ISM processes but becomes less reliable when introducing the hot plasma found in superbubbles or the CGM.
Our work...
Shocks are key drivers of dust destruction in the interstellar medium (ISM), significantly influencing gas-phase element abundances. Feedback processes from active galactic nuclei (AGN), such as outflows and jets, generate shocks that create hostile environments where dust is expected to undergo extensive processing or destruction. However, recent observations reveal that dust grains and...
Observations and simulations both reveal that circumgalactic medium (CGM) gas is highly dynamic and inhomogenous, with signs of turbulent, rotational, and bulk flow motions. In particular, turbulent gas motions can be measured in both absorption and emission lines as line broadening, but it is unclear what drives these turbulent motions and how well such observations trace the true structure...
Measurements of the star formation histories (SFHs) of galaxies enable comparisons to theoretical models of galaxy formation and evolution. While there are several methods that can measure galactic SFHs, the measurements with the greatest precision and time resolution are made by modelling resolved photometry of stellar populations obtained from space-based observatories (e.g., HST/ACS and...
Galactic outflows crucially transfer baryons and energy across the ISM and CGM, affecting the stellar formation history and the distribution of metals. However, the survival of cold gas in these outflows remains uncertain due to the turbulent, multiscale nature of interactions between different gas phases. In this work, we extend the current understanding of outflow dynamics by bridging...
Supernova and radiative feedback effects are one of the main cursors that drove early galaxy formation. The strength of these feedback effects can preferentially drive metals to variable distances into the outer halo of galaxies. I postprocess SPICE, a suite of radiation-hydrodynamics simulation targeting the epoch of reionisation, to study the impact of different modes of stellar feedback on...
The well-known stellar mass-metallicity relation observed in galaxies shows significant increase in scatter and a metallicity plateau in the regime of ultra-faint dwarfs (UFDs). Two mechanisms may lead to this: pre-enrichment of accreted gas, or internal enrichment and modulation by metal outflow. We consider the role both processes play in driving the observed relation. We study...
Star formation and its subsequent feedback are fundamental processes shaping the ecology of galaxies. However, the details on how they affect the local properties of the interstellar medium (ISM) as well as shape galactic-scale star formation histories are currently actively debated. In my talk I will use the high resolution (20 pc) VINTERGATAN cosmological zoom-in simulation to study the...
The correct description of cosmic ray transport in the circumgalactic media of galaxies and in the intracluster gas suffusing larger halos is an active area of research. I will outline results we have obtained from a high-level treatment of cosmic ray injection, transport, and energy loss in dark matter halos. There are three limiting cases: i) cosmic rays are accumulated over cosmic...
Mediated by magnetic field fluctuations, cosmic rays give and take energy from the thermal gas. That energy conversion depends on how cosmic rays are transported. As the local Alfven speed changes, their transport can switch between diffusion, streaming, and advection. Because of the change in density and magnetic field strength between the galactic disk and the galactic halo, there could be a...
In galactic and intergalactic environments, gas flows often exhibit relative motion between cold dense gas and a hot diffuse medium. These multiphase flows are often subject to large-scale turbulence. Such scenarios ubiquitously arise in the circumgalctic medium, such as in galactic winds, fountain flows, and filamentary accretion from the intergalactic medium. Turbulence plays a crucial role...
The number of active galactic nuclei (AGN) in galaxy clusters has been observed to grow by nearly two orders of magnitude from the local universe to $z \sim 1.5$. Star formation rates in clusters have also been observed to rise rapidly over this redshift interval. These trends, along with several other recent observations of high-redshift clusters, have led to the idea that this enhanced star...
I will present recent high-resolution measurements of ISM structure, radiation feedback, and PAH fractions in nearby galaxies based on mid-infrared emission and optical spectroscopy from the PHANGS JWST and MUSE surveys. JWST mid-IR images reveal complex substructure that simultaneously traces the distribution of dust and gas as well as heating from young stars. We measure the distribution...
Galaxies undergo significant evolution from the early Universe to the present day; feedback processes are vital ingredients needed to help untangle the details of this transformation. Powerful jets driven by active galactic nuclei (AGN) have a key role in suppressing gas cooling, thus modulating the cooling gas that infalls into the host galaxy's centre. These radio jets inflate large lobes...
AGNs flicker in bursts lasting ${\sim}0.1$ Myr, punctuated by quiescent intervals. Despite the low duty cycle, the total energy released exceeds the binding energy of the galactic bulges. This indicates that AGN-released energy couples inefficiently to the surrounding gas, but can still affect the host galaxy, for example via wind-driven outflows. Indeed, fast (${>}500$ km s$^{-1}$) outflows...
With the rise of integral field spectroscopy, the complexity of the data analysis has grown significantly. This is particularly true for studies of active galactic nuclei (AGN), where there is a complex interplay between large amounts of gas and dust across different scales. The James Webb Space Telescope (JWST) offers a new opportunity to study the properties of local AGN and (ultra)luminous...
The advent of JWST has allowed us to peer further into the Universe than we've ever been able to before. With over 20 galaxies observed beyond redshift 10, we are now able to observe the formation of galaxies at a time where we still expect the formation of population III (Pop III) stars. In this talk, I will introduce the MEGATRON simulation and its prescription for the formation of...
My research project focuses on cosmic rays and their models in galaxy simulation. In particular, the aim is to implement in RAMSES a multi-group approach for cosmic rays, where their energy distribution is taken into account for their transport and cooling processes. This project is part of an effort to better constrain cosmic ray models to understand their role in galaxy feedback.
Galaxy clusters are the rarest and largest gravitationally bound structures in the Universe. They are sensitive tracers of the structure on the largest scales and provide constraints on fundamental physics and cosmology. Clusters are, additionally, ideal cosmic laboratories that can be used to explore the effects of, and coupling between, a diverse range of astrophysical feedback processes....
The circumgalactic medium (CGM) plays a pivotal role in galaxy evolution: accretion of cool, metal-poor gas from the cosmic web can feed star formation and AGN activity, but outflows heat and chemically enrich the CGM gas, leading to self-regulating feedback processes.
At z>3, quasars are commonly embedded into large Lyman $\alpha$ nebulae extending up to the virial radius of the host...
This study uses cosmological `zoom-in' simulations to understand gas and metal mixing in a simulated Milky Way (MW)-mass galaxy's circumgalactic medium (CGM). To track mixing, we insert tracer dyes in the CGM representing diverse gas flows and physical properties, including shearing inflows-outflows, coherent inflows, coherent outflows, and static gas. We find that mixing is higher for...
Feedback from cosmic rays (CRs) is expected to contribute to the regulation of star-formation in the ISM and the acceleration of a galactic outflow. The impact of CRs, however, depends on the microphysical transport processes. We run high-resolution "tallbox" simulations of the multiphase interstellar medium (ISM) and galactic wind using the moving mesh magnetohydrodynamics code AREPO, the...
Feedback from black hole-powered jets has been invoked in many cosmological simulations to regulate star formation and quench galaxies. Despite this, observational evidence of how jets might be able to affect their hosts remains scarce, especially for low power jets in halos smaller than clusters. Recent observations of outflows around FR0 galaxies, that host compact radio-loud sources, imply...
The impact of active galactic nucleus (AGN) radiation feedback on galaxy evolution remains an open question in astrophysics, particularly regarding its ability to regulate star formation and drive outflows. In this work, we present a detailed investigation of AGN radiation feedback using state-of-the-art cosmological simulations, analyzing its effects on gas thermodynamics, metal enrichment,...
Stellar feedback creates channels facilitating Lyman photon escape from starburst galaxies into the galactic halo. Although leakage from low-metallicity (low-Z) galaxies is a prime candidate for explaining cosmic reionization, it remains poorly understood. High-mass X-ray binaries and superbubbles can dominate over massive stars and super star clusters as the main contributors of ionizing...
Active Galactic Nuclei (AGNs) and young stars in high redshift galaxies are believed to be two main sources of photoionizing UV radiation during Epoch of Reionization (EoR), however their relative contribution remains uncertain due to uncertainties related to the ionizing photon escape fractions. While there are detailed studies consistent with observations which conclude that HI ionizing...
Star formation is a key process that governs the baryon cycle within galaxies, but how it controls their growth remains elusive due to modeling uncertainties. To understand the impact of star formation models on galaxy evolution, we perform cosmological zoom-in radiation-hydrodynamic simulations of a dwarf dark matter halo with virial mass $M_{\rm vir} \sim 10^{10}\,M_\odot$ at $z=6$. Two...
Metal absorption lines are powerful tools for probing the gas content in the universe and illuminating the gas flows around galaxies. Absorption that arises from different ionization states of chemical elements provides insight into various gaseous structures and environments – low-ionization lines trace the cooler, denser regions near galaxies, while high-ionization lines illuminate the...
AGN feedback plays a crucial role in regulating star formation and shaping galaxy evolution. While the role of outflows and radio jets in high-luminosity AGN such as quasars is well-documented, feedback mechanisms in lower luminosity AGN remain poorly understood. In this study, we focus on a unique sample of ten low-excitation radio galaxies (exhibiting >5 times lower radio power than their...
Recent high-redshift observations from JWST and ALMA have revealed disc-like structures existing as early as redshift z ∼ 9. Some of these discs exhibit evidence of being dynamically cold, with rotation-to-dispersion support of Vrot/σ ≥ 4 at redshifts z > 4. These findings are in tension with predictions from cosmological simulations, as many struggle to reproduce dynamically cold discs at...
AGN-driven jets are frequently observed in galaxies, yet their interaction with the host's ISM remains poorly understood. In our studies (Meenakshi et al. 2022a,b), we use results from resolved simulations of jet-ISM interactions within the nuclear regions of host galaxies to investigate the extent of ionization, thermal shocked emission, and shocked gas kinematics. Our analysis indicates that...
Extremely red quasars provide crucial insights into galaxy evolution, as they represent an obscured phase of quasar growth and a potential early blowout stage driven by quasar feedback. However, directly studying their host galaxies is challenging because the intense quasar emission often outshines the underlying stellar populations. Understanding these hosts is essential for constraining the...
Studying gas kinematics in the circumnuclear regions of a galaxy provides crucial insights into how gas is transported toward the supermassive black hole, fueling an active galactic nucleus (AGN), which itself can trigger feedback. We present NOEMA CO(2-1) observations of the nearby Compton-thick AGN NGC 3079, with an angular resolution of 0.5′′ (~40 pc). On larger scales, both the...
The Lyman-alpha (Lya) emission line is a powerful tool for studying the circumgalactic medium (CGM) of high redshift galaxies. Large-scale gas flows induced by feedback as well as accretion, mediated by resonant scattering at HI gas, imprint themselves through the skewed spectral shape of the line and the frequent presence of two distinct peaks. Recent obervations revealed for the first time a...
Observations of Faraday rotation and synchrotron emission in galaxy clusters suggest the presence of large-scale magnetic fields with $\mu$G strengths, possibly extending back to $z=4$. We investigate how galaxy formation physics and feedback processes drive the rapid growth of these magnetic fields at high redshift. In the early stages, the central dominant galaxy plays a key role in...
Most recent numerical models of the multiphase interstellar medium (ISM) in disk galaxies have demonstrated the importance of cosmic rays (CRs) and magnetic fields for the physics of the ISM including the launch of galactic winds. These components of the ISM contribute significantly to the total pressure and thus influence the large scale distribution of the ISM and its evolution....
Galactic winds are an important but understudied component of feedback processes. Recent studies have shown that winds are a prevalent feature in normal star-forming galaxies. However, it remains a challenge to quantify the mass, momentum, and energy they transport, and to understand their driving mechanisms.
To tackle this problem, our ongoing research makes innovative use of H I 21 cm...
Cosmic dust is a fundamentally important component of the interstellar medium, both for its impact on observable quantities and its dynamical influence on the ISM. Dust grains potentially mediate feedback mechanisms such as radiation pressure, multiple cooling and heating processes, and the coupling of neutral gas to magnetic fields. However, the importance and relative strengths of these...
Magnetic fields play a crucial role in shaping the properties of the intracluster medium and influencing galaxy cluster evolution.
In this talk, we present a census of the general properties and morphology of magnetic fields in the TNG-Cluster simulation, a new suite of cosmological zoom simulations that self-consistently model magnetic fields, focusing on the highest mass galaxy clusters....
"AGN feedback" -- the cumulative effect of energy released by material accreting onto a supermassive black hole on its local and "global" surroundings -- is a critical ingredient of models for the formation and evolution of galaxies. However, the variety of physical mechanisms by which energy released in the central parsecs impacts material thousands to millions times further away are poorly...
Feedback processes play a crucial role in driving galactic outflows that shape galaxy evolution, regulate star formation, and promote the cosmic baryon cycle. Multiwavelength observations consistently reveal that these outflows are inherently multiphase. However, reconciling such observations with numerical simulations remains a major challenge due to the computational cost of capturing the...
The circumgalactic medium (CGM) is the gaseous medium extending far beyond the stellar disk of a galaxy. Recent observations have revealed that it has a rich multiphase structure, i.e., it hosts gas at different densities, temperatures, and ionization states. The complex gas dynamics in the CGM plays a crucial role in establishing gas flows in and out of the galactic disk, regulating star...
The circumgalactic medium (CGM) plays a central role in galaxy evolution
by acting as a gateway for the inflow and outflow of gas and metals, thus
directly influencing star formation and chemical enrichment processes.
By combining imaging and spectroscopy, we can now study the halo
of galaxies in absorption and relate it to galaxy orientation and further
obervable properties. In...
We present predictions for the non-thermal pressure (NTP) induced in galaxy clusters undergoing energetic jet outbursts from an active galactic nucleus (AGN). Our model simulates a population of jets from power-law distributions in their power and age, which are analytically modelled as they propagate through the intracluster medium. We model the energy coupling between the jet and the...
I will present our recent numerical simulation results of the evolution of a disk galaxy with the effects of AGN feedback. The simulation is based on our MACER framework. Different from cosmological simulations, MACER focuses on galactic scale, thus has very high spacial resolution. The inner boundary of the simulation is smaller than the Bondi radius of the accretion flow so we can reliably...
Observations from radio to X-ray have shown that multiphase material is present in the proximity of the center of our Galaxy and it is likely associated with strong galactic outflows. Such an environment represents therefore a unique and ideal laboratory to study in detail the physics of feedback and multiphase gas. To this purpose, we have developed self-consistent semi-analytical models of...
OI absorbers are critical probes of metal enrichment in the intergalactic medium (IGM) during the epoch of reionization (EoR). We present a detailed comparison of OI absorbers in high-resolution cosmological simulations and recent observational datasets, focusing on their ability to trace the spatial distribution and physical conditions of metals in the IGM. This analysis highlights the role...
Active galactic nuclei (AGN) play a critical role in galaxy evolution, shaping star formation (SF) and the interstellar medium (ISM) through energetic winds, outflows and jets. In this talk, I will present a spatially resolved study of the warm molecular gas phase in two type-2 quasars (i.e. obscured quasars) from the Quasar Feedback (QSOFEED) sample: SDSS J1356+1026 and SDSS J1430+1339 (the...
SKA precursors are already challenging our understanding of the prevalence of radio AGN across cosmic time. It is vital that that we have the means to interpret these observations in the context of the larger galaxy population and at a cosmological scale. I will present a comparison between radio galaxies in the SIMBA cosmological simulations with that of the MIGHTEE radio continuum survey,...
Feedback by active galactic nuclei (AGN) jets is thought to prevent cooling flows in cool-core galaxy clusters. Cosmic ray electrons are believed to be accelerated at internal shocks in these jets, leading to the synchrotron radio emission observed in radio galaxies and jet-inflated radio lobes. The lobes inflated over multiple AGN feedback duty cycles rise buoyantly in the intra-cluster...
The formation of galaxies is significantly influenced by galactic winds, possibly driven by cosmic rays due to their long cooling times and better coupling to plasma compared to radiation. In this study, we compare the radio observations of the edge-on galaxy NGC 4217 from the CHANG-ES collaboration catalog with a mock observation of an isolated galaxy based on the Arepo simulation that adopts...
For the first time, JWST enables exquisite spatially resolved spectral maps of galaxies when the universe was only 3 billion years old. We present such maps for a galaxy, which we call the “Coffee Pot.” It has morphology and gas kinematics consistent with a major merger, but was classified as a disk from ground based observations. It has centralized, compact star formation as measured from...
The new generation of radio telescopes has unveiled a rich structure of non-thermal radio emissions in galaxy clusters. Among these, radio relics and radio halos stand out as the primary sources, attributed to the synchrotron radiation of relativistic electrons. These structures provide unique insights into in-situ particle acceleration mechanisms and the large-scale magnetic field...
Star formation lies at the core of the evolutionary cycle of galaxies. To better understand the mechanisms involved in star formation, we need to study the influence of the local interstellar medium (ISM) and the lifecycle of giant molecular clouds (GMCs). In this work, we study the influence of the local environment of the giant molecular clouds on the star formation process and measure the...
Around 90% of the baryons in the Universe lie in the intergalactic medium (IGM) and remain significantly less understood than the matter associated with starlight, such as galaxies. In this talk, I will introduce the Baryon Cycle (ByCycle) project, an upcoming 4MOST-VISTA survey that aims to uncover these hidden baryons. Our survey will consist of high-resolution (R ~ 20000) spectra of a large...
The relationships between supermassive black holes (SMBHs), galaxies, and dark matter halos can reveal information about the feedback processes that regulate black hole and galaxy growth. While the SMBH-galaxy and galaxy-halo connections have been fairly well-characterized in the last two decades, the SMBH-halo connection remains less constrained. By measuring the clustering statistics of hard...
Understanding how and when the intergalactic medium was enriched with metals can provide us with new insights into the efficiency of galactic feedback. Spectroscopic studies of high-redshift quasars have been essential in revealing numerous metal ions in the intervening intergalactic medium, and the advent of JWST has further extended these detections to higher redshifts, into the Epoch of...
The halos surrounding spiral galaxies act as a bridge between the galaxy and the Intergalactic Medium (IGM). It is therefore of paramount importance to gain a deeper knowledge of the nature and kinematics of this medium. They host most of the baryonic mass in the Universe, and many authors point to SF- or AGN-driven feedback as one of the main mechanisms regulating the presence of baryons...
The baryon cycle is a key aspect of galaxy formation and evolution which connects different objects and scales together, from individual stars within galaxies to gaseous structures in their surrounding halos. I will present recent work where I have examined multiple aspects of the baryon cycle with different simulations. Using RAMSES zoom-in simulations, I studied the potential effects of...
Gas deposition processes in the galaxy play a critical role for the promotion of thin discs, e.g. the hot mode accretion allows the mixing of gas in the circum-galactic medium (CGM), leading to a more coherent accretion, and enhancing the disc formation. But there is no consensus on how the gas accretion proceses affect the CGM or how are manifested in models.
In this work we use five...
The JWST has discovered an abundance of z>10 luminous galaxies that were not predicted by galaxy formation models. One common explanation for such striking observation invokes an increased star formation burstiness to reconcile modeling and observations. Such increased burstiness, however, is reflected in the pattern of pre-SN and SN feedback. I will show how such feedback has dramatic...
Cosmic rays (CRs), with their substantial energy density, play a key role in the evolution of galaxies, and in shaping their interstellar mediums (ISM). Accelerated in supernova (SN) shocks, CRs propagate along magnetic field lines, distributing energy and momentum throughout the galaxy. This process ionizes and heats the gas and drives large galactic outflows by creating pressure gradients,...
The MUSE Ultra-Deep Field (MUDF) is the deepest field observed with MUSE to-date, with over 140h of observations covering a 2’x2’ field centered on a pair of z~3 quasars. This is accompanied by numerous datasets from other instruments including ALMA, HAWK-I, UVES, and XMM-Newton, as well as multi-band HST imaging and the deepest ever WFC3 grism survey. We measure morphologies, stellar masses,...
Young, massive stars form in molecular clouds and shape their surroundings through powerful feedback mechanisms: stellar winds, ionizing radiation, and supernova explosions. Some fraction of ionizing photons escapes into the wider galaxy, further influencing star formation and galactic evolution. Understanding the interplay between these stars and the interstellar medium is key to unravelling...
Active galactic nuclei (AGN) drive powerful, multiphase outflows into their host galaxies which are expected to play a key role in galaxy evolution. However, exactly how small-scale accretion disc winds couple to the ISM to drive these outflows remains an open question. In this talk, I will present our AGN in Clumpy DisCs (ACDC) simulations which feature a physically-motivated AGN wind model...
Galactic bars are interesting central features that are thought to drive gas from the galactic disk towards the center of a galaxy through bar lanes. This gas inflow can trigger nuclear star formation, fuel supermassive black holes (SMBHs) and, indirectly, it can control active galactic nucleus (AGN) feedback. Therefore, measuring inflow rates is key to understanding the evolution of galactic...
The study of galaxy formation and evolution has progressed significantly in recent decades, with numerical simulations producing galaxies matching observed properties. However, the inner workings of the feedback processes that regulate the growth of galaxies are not fully understood. To address this, a new generation of high-resolution simulations has been developed, using subgrid models to...
