arXiv subjects

Marine Prunier

Publications and source records attributed to Marine Prunier.

10 recordsLinked to original sources

arXiv2026

Mapping gas accretion and stellar kinematics to sub-kiloparsec scales in NGC 4696 with JWST/NIRSpec

We present JWST/NIRSpec IFU spectroscopy of the central $618\times618$ pc$^2$ ($\sim3''\times3''$) of NGC 4696, the BCG in the Centaurus cluster. Leveraging the $\sim0.1''$ ($20.6$ pc) pixel size of JWST, we resolve a compact circumnuclear rotating disk (radius of $\sim120$ pc) traced by Pa$\alpha$ and H$_2$ 1$-$0 S(1) emission, which allows a reassessment of the AGN position based on the kinematic centre of this disk. A central Pa$\alpha$ velocity dispersion reaching $\sigma\sim449$ km s$^{-1}$ implies a SMBH mass of $\sim10^9$ M$_\odot$, corresponding to a sphere of influence of $r_\mathrm{inf}\sim60$ pc, resolved by our observations. Position-velocity diagrams reveal an increase from $\sim-200$ to $\sim600$ km s$^{-1}$ on scales of $\sim150$ pc (a gradient of $4.7$ km s$^{-1}$ pc$^{-1}$) and an accretion rate of $\sim18$ M$_\odot$ yr$^{-1}$ feeding the CND. The Pa$\alpha$ emission shows a double-component in the core, with a high-dispersion redshifted component reaching $\sigma\sim600$ km s$^{-1}$. In contrast, MUSE H$\alpha$ observations covering the $\sim10$ kpc-scale filamentary structure recover only weak velocity gradients ($\lesssim150$ km s$^{-1}$) within $\sim300\times300$ pc$^2$ and do not resolve the disk due to larger PSFs and pixel sizes. ALMA CO(2-1) data reveal only compact molecular clumps within a $\sim410\times410$ pc$^2$ region, with no extended counterpart to the structures traced by Pa$\alpha$ and H$_2$ 1$-$0 S(1). Stellar kinematics show a smooth velocity field and broad dispersion profile, clearly decoupled from both the multiphase gas and the hot ICM probed by XRISM. These results provide a direct, spatially resolved view of gas dynamics within the inner few hundred parsecs, demonstrating the power of JWST/NIRSpec to probe SMBH feeding.

astro-ph.GA↗

arXiv2026

JWST reveals how black holes are fed: kiloparsec-scale multiphase filaments feed sub-kiloparsec circumnuclear disks

The Centaurus cluster is one of the most important archetypes of radio-mode AGN feedback, with its central galaxy, NGC 4696, launching powerful jets that inflate X-ray cavities and regulate cooling and star formation. NGC 4696 lies within a spectacular multiphase nebula of filaments extending over tens of kiloparsecs and spanning six decades in temperature, from hot (10^8 K) X-ray-emitting plasma to cold molecular gas. Owing to its proximity, Hubble Space Telescope H_alpha imaging reveals a striking S-shaped ionized-gas swirl within the black hole's sphere of influence - the first such structure identified in a cluster core. Here we present the first JWST observations of NGC 4696 with NIRSpec, probing the inner 618 pc * 618 pc at 10 pc resolution. These data reveal that the ionized swirl is a rotating, multiphase circumnuclear disk (CND) physically and kinematically connected to the larger-scale filamentary network. This provides the long-sought missing link between kiloparsec-scale cooling flows and black hole accretion on <100 pc scales. Strikingly, the observed morphology and kinematics are reproduced by tailored magnetohydrodynamic simulations, in which filamentary gas condenses from the hot atmosphere, loses angular momentum, and feeds a rotating CND that mediates accretion onto the black hole. A similar structure in NGC 1275, the Perseus cluster's central galaxy, together with our results on NGC 4696 - two prototypical radio-mode AGN feedback systems - points to a common mechanism: multiphase filaments transport gas from cluster scales down to the vicinity of the black hole via a CND, closing the AGN feedback loop and establishing a physically grounded framework for self-regulated galaxy evolution.

astro-ph.GA↗

arXiv2026

Bulk vs. turbulent motions at the centres of galaxy clusters: AGN-driven turbulence according to TNG-Cluster

The highly dynamic intracluster medium (ICM) influences cluster thermodynamic evolution and probes key physical processes. Quantifying the non-thermal motions is therefore essential for understanding cluster physics and interpreting high spectral-resolution X-ray observations from telescopes like {\it XRISM}. We quantify bulk and turbulent gas motions in 352 galaxy clusters at $z=0$ (${\rm M_{200c}=10^{14.3-15.4}\, M_\odot}$) from the TNG-Cluster suite of magneto-hydrodynamical galaxy simulations. We use a multi-scale filtering Reynolds decomposition to separate total gas velocities into bulk (coherent) and turbulent (small-scale fluctuations) components. We primarily focus on the hot X-ray emitting gas in the central core regions. According to TNG-Cluster, majority of the ICM has subsonic turbulence but with broad velocity distributions reaching $\mathcal{M}_{\rm Turb}\sim 10$ and large cluster-to-cluster variations. In cluster centres, turbulence contributes less than half of the total velocity dispersion $(\sigma_{v\rm,Turb } \sim 0.5 ~\sigma_{v,\rm Total})$ for most clusters, with typical turbulent velocity dispersions of $50-75$ km s$^{-1}$ across the mass range, and with sub per cent levels of turbulent pressure support. Clusters that are strong cool cores, or have X-ray cavities, or experienced recent SMBH feedback energy injections exhibit systematically larger turbulent velocity dispersions and more prominent turbulent velocity tails. On average, the turbulent velocity dispersion peaks in cluster centres, decreases slightly to a minimum at $0.1-0.2 \, R_{\rm500c}$, then rises again. Our analysis shows that SMBH feedback is a key driver of turbulence in cluster cores, generating strong but short-lived motion alongside high-velocity outflows. It also calls for caution for interpreting {\it XRISM} observations.

astro-ph.GA↗

arXiv2025

X-ray shocks in the cool cores of galaxy clusters: insights from TNG-Cluster

Shock fronts driven by active galactic nuclei in galaxy cluster cores represent a promising mechanism to heat the intracluster gas by converting kinetic energy into thermal energy through gas compression, thereby offsetting radiative cooling. Despite their potential importance, such shocks are challenging to detect, requiring deep X-ray exposures, and have only been identified in ten clusters. We present the first systematic detection and characterization of AGN-driven shocks in simulated clusters from the TNG-Cluster magnetohydrodynamic cosmological zoom-in simulations of galaxies. TNG-Cluster exhibits a rich variety of X-ray structures, including realistic populations of X-ray cavities, as well as shocks, produced by its AGN feedback model, without collimated, relativistic jets, nor cosmic rays. We produce mock Chandra observations with deep exposure times, for a sample of 100 clusters, mass-matched (M$_{500c}=1.2$ - $8.5 \times 10^{14}$ M$_\odot$) to the ten observed clusters with shocks. Using observational techniques, we identify shocks through surface brightness edges fitted with broken power laws and associated density and temperature jumps. We detect 50 shocks in 30 of the 100 clusters, with ~35% hosting multiple shocks. These shocks lie within a hundred kiloparsec of the central SMBH, are weak (Mach number < 2, median ~ 1.1), and are associated with cavities in about half of the cases. Both in observations and in TNG-Cluster, shocks tend to be located at larger radii than cavities, with median offsets of 46 and 27 kpc, respectively. The observationally inferred shock powers are comparable to the cluster cooling luminosities (10$^{44-46}$ erg s$^{-1}$), suggesting that shocks in the simulation are crucial heating mechanisms. Our results indicate that shocks play a role as important as cavities in balancing cooling in cluster cores, acting isotropically and up to larger distances.

astro-ph.GA↗

arXiv2025

Magnetic fields in the intracluster medium with TNG-Cluster: properties, morphology, and tangential anisotropy

We characterize the magnetic field properties of 352 massive galaxy clusters from the TNG-Cluster magnetohydrodynamical cosmological simulation with a focus on central magnetic field morphology in cool-core (CC) vs non-cool-core (NCC) clusters. We present the central values and radial profiles of magnetic field strength and plasma parameter as a function of mass, cooling status and redshift. Compared to low-redshift observations, TNG-Cluster produces reasonable magnetic field amplitudes in the central regions of clusters spanning a range of 1-200 muG. We then discuss the main finding of this work: z=0 cool-core clusters have preferentially tangential magnetic fields at a characteristic scale of ~ 0.1 r500c. These strongly tangential field orientations are specific to CCs. In contrast, across the full cluster population, magnetic fields show isotropic configurations at all radii and redshifts. As individual halos grow, the evolution of their magnetic field topologies is diverse: tangential features can be short-lived, persist over large cosmological time-scales, or periodically appear, vanish, and reappear towards z=0. We discuss the underlying physics and possible physical scenarios to explain the origin of these structures. We argue that both AGN feedback-driven outflows, and merger-driven sloshing motions, cannot explain the population-wide tangential bias in magnetic field orientation. Instead, we propose that the trapping of internal gravity waves is responsible for the tangentially biased magnetic field topologies that we find in cool-core TNG-Cluster halos, due to the strong entropy gradient in these clusters.

astro-ph.GA↗

arXiv2025

X-ray cavities in TNG-Cluster: a direct comparison to observations

The TNG-Cluster magnetohydrodynamic cosmological simulations, produce a diverse population of X-ray cavities in the intracluster medium (ICM) of simulated galaxy clusters. These arise from episodic, high velocity, kinetic energy injections from the central active supermassive black hole (AGN, SMBH). Here, we present the first comprehensive comparative analysis of X-ray cavities in TNG-Cluster with observational data. First, we select a volume-limited sample of 35 real clusters ($z \leq 0.071$, M$_\text{500c}$ = 10$^{14-14.8}$ M$_\odot$) observed with the Chandra X-ray Observatory, identify 3 analogs for each in TNG-Cluster (total of 105) and generate mock Chandra images using same exposure times as their observed counterparts. We identify X-ray cavities and measure their properties in both datasets using identical techniques, ensuring a direct, apples-to-apples comparison. Our analysis reveals that both samples have a similar fraction of X-ray cavities (35-43 per cent). They exhibit comparable sizes and morphologies, although the sizes of simulated X-ray cavities still attached to the SMBH are somewhat larger in TNG-Cluster -- a scarcity at $< 10$ kpc. The area of TNG X-ray cavities increases as they rise in the ICM, consistent with the trend seen in the observational sample. The cavity powers, estimated using observational techniques, show good agreement between the two samples (10$^{42-45}$ erg.s$^{-1}$), suggesting that X-ray cavities in the simulation are an important heating mechanism in cluster cores. Overall, the rather simple AGN feedback model of TNG, with no model choices made to reproduce X-ray morphological features, and without cosmic rays, creates a quantitatively realistic population of X-ray cavities at cluster scales.

astro-ph.GA↗

arXiv2025

HST Observations within the Sphere of Influence of the Powerful Supermassive Black Hole in PKS0745-191

We present Space Telescope Imaging Spectrograph observations from the Hubble Space Telescope of the supermassive black hole (SMBH) at the center of PKS0745-191, a brightest cluster galaxy (BCG) undergoing powerful radio-mode AGN feedback ($P_{\rm cav}\sim5\times10^{45}$ erg s$^{-1}$). These high-resolution data offer the first spatially resolved map of gas dynamics within a SMBHs sphere of influence under such powerful feedback. Our results reveal the presence of highly chaotic, non-rotational ionized gas flows on sub-kpc scales, in contrast to the more coherent flows observed on larger scales. While radio-mode feedback effectively thermalizes hot gas in galaxy clusters on kiloparsec scales, within the core, the hot gas flow may decouple, leading to a reduction in angular momentum and supplying ionized gas through cooling, which could enhance accretion onto the SMBH. This process could, in turn, lead to a self-regulating feedback loop. Compared to other BCGs with weaker radio-mode feedback, where rotation is more stable, intense feedback may lead to more chaotic flows, indicating a stronger coupling between jet activity and gas dynamics. Additionally, we observe a sharp increase in velocity dispersion near the nucleus, consistent with a very massive $M_{\rm BH}\sim1.5\times10^{10} M_\odot$ SMBH. The density profile of the ionized gas is also notably flat, paralleling the profiles observed in X-ray gas around galaxies where the Bondi radius is resolved. These results provide valuable insights into the complex mechanisms driving galaxy evolution, highlighting the intricate relationship between SMBH fueling and AGN feedback within the host galaxy.

astro-ph.GA↗

arXiv2024

X-ray cavities in TNG-Cluster: AGN phenomena in the full cosmological context

Active galactic nuclei (AGN) feedback from supermassive black holes (SMBHs) at the centers of galaxy clusters plays a key role in regulating star formation and shaping the intracluster medium (ICM), often manifesting through prominent X-ray cavities embedded in the cluster's hot atmosphere. Here we show that X-ray cavities arise naturally due to AGN feedback in TNG-Cluster. This is a new suite of magnetohydrodynamic cosmological simulations of galaxy formation and evolution, and hence of galaxy clusters, whereby cold dark matter, baryon dynamics, galactic astrophysics, and magnetic fields are evolved together consistently. We construct mock Chandra X-ray observations of the central regions of the 352 simulated clusters at $z=0$ and find that $\sim$39 per cent contain X-ray cavities. Identified X-ray cavities vary in configuration (single, pairs, or multiples), with some still attached to SMBHs, while others have buoyantly risen. Their size ranges from a few to several tens of kpc. In terms of gas physical properties, TNG-Cluster X-ray cavities are underdense compared to the surrounding halo and filled with hot gas ($\sim$10$^8$K); 25 per cent of them are surrounded by an X-ray bright and compressed rim associated with a weak shock (Mach number $\sim 1.5$). Clusters exhibiting X-ray cavities are preferentially strong or weak cool-cores, are dynamically relaxed, and host SMBHs accreting at low Eddington rates. We show that TNG-Cluster X-ray cavities originate from episodic, wind-like energy injections from central AGN. Our results illustrate the existence and diversity of X-ray cavities simulated in state-of-the-art models within realistic cosmological environments and show that these can form without necessarily invoking bipolar, collimated, or relativistic jets.

astro-ph.GA↗

arXiv2024

Deconvolving X-ray Galaxy Cluster Spectra Using a Recurrent Inference Machine

Recent advances in machine learning algorithms have unlocked new insights in observational astronomy by allowing astronomers to probe new frontiers. In this article, we present a methodology to disentangle the intrinsic X-ray spectrum of galaxy clusters from the instrumental response function. Employing state-of-the-art modeling software and data mining techniques of the Chandra data archive, we construct a set of 100,000 mock Chandra spectra. We train a recurrent inference machine (RIM) to take in the instrumental response and mock observation and output the intrinsic X-ray spectrum. The RIM can recover the mock intrinsic spectrum below the 1-$\sigma$ error threshold; moreover, the RIM reconstruction of the mock observations are indistinguishable from the observations themselves. To further test the algorithm, we deconvolve extracted spectra from the central regions of the galaxy group NGC 1550, known to have a rich X-ray spectrum, and the massive galaxy clusters Abell 1795. Despite the RIM reconstructions consistently remaining below the 1-$\sigma$ noise level, the recovered intrinsic spectra did not align with modeled expectations. This discrepancy is likely attributable to the RIM's method of implicitly encoding prior information within the neural network. This approach holds promise for unlocking new possibilities in accurate spectral reconstructions and advancing our understanding of complex X-ray cosmic phenomena.

astro-ph.GA↗

arXiv2023

Analysis of the subsolar-mass black hole candidate SSM200308 from the second part of the third observing run of Advanced LIGO-Virgo

A follow-up of a subsolar black hole candidate identified in the second part of the third observing run of the LIGO-Virgo-KAGRA collaboration is carried out. With a search signal-to-noise ratio of $8.90$ and a false-alarm rate of 1 per 5 years, close to the usual thresholds for claiming a gravitational-wave event, we cannot exclude a noise origin. A complete Bayesian parameter estimation of this candidate, denoted SSM200308, reveals that if the signal originates from a compact binary coalescence, the component masses are $m_1= 0.62^{+0.46}_{-0.20} M_{\odot}$ and $m_2 = 0.27^{+0.12}_{-0.10} M_{\odot}$ (90% credible intervals) with at least one component being firmly subsolar, below the minimum mass of a neutron star. This discards the hypothesis that the signal comes from a standard binary neutron star. The signal coherence test between the two LIGO detectors brings support to a compact object coalescence origin.

gr-qc↗