17 research outputs found
Physical processes that determine the clustering of different types of galaxies on large scales
Feedback reshapes the baryon distribution within haloes, in halo outskirts, and beyond: the closure radius from dwarfs to massive clusters
We explore three sets of cosmological hydrodynamical simulations,
IllustrisTNG, EAGLE, and SIMBA, to investigate the physical processes impacting
the distribution of baryons in and around haloes across an unprecedented mass
range of , from the halo centre out
to scales as large as . We demonstrate that baryonic feedback
mechanisms significantly redistribute gas, lowering the baryon fractions inside
haloes while simultaneously accumulating this material outside the virial
radius. To understand this large-scale baryonic redistribution and identify the
dominant physical processes responsible, we examine several variants of TNG
that selectively exclude stellar and AGN feedback, cooling, and radiation. We
find that heating from the UV background in low-mass haloes, stellar feedback
in intermediate-mass haloes, and AGN feedback in groups () are the dominant processes. Galaxy clusters are
the least influenced by these processes on large scales. We introduce a new
halo mass-dependent characteristic scale, the closure radius ,
within which all baryons associated with haloes are found. For groups and
clusters, we introduce a universal relation between this scale and the halo
baryon fraction: , where , and
and are free parameters fit using the simulations.
Accordingly, we predict that all baryons associated with observed X-ray haloes
can be found within . Our results can be
used to constrain theoretical models, particularly the physics of supernova and
AGN feedback, as well as their interplay with environmental processes, through
comparison with current and future X-ray and SZ observations.Comment: Submitted to MNRA
The hot circumgalactic media of massive cluster satellites in the TNG-Cluster simulation: existence and detectability
The most massive galaxy clusters in the Universe host tens to hundreds of
massive satellite galaxies, but it is unclear if these satellites are able to
retain their own gaseous atmospheres. We analyze the evolution of
satellites of stellar mass around 352 galaxy
clusters of mass at from the new
TNG-Cluster suite of cosmological magneto-hydrodynamical galaxy cluster
simulations. The number of satellites per host increases with host mass, and
the mass--richness relation broadly agrees with observations. A halo of mass
hosts
satellites today. Only a minority of satellites retain some gas, and this
fraction increases with stellar mass. Lower mass satellites
are more likely to retain part of their cold
interstellar medium, consistent with ram pressure preferentially removing hot
extended gas first. At higher stellar masses the
fraction of gas-rich satellites increases to unity, and nearly all satellites
retain a sizeable portion of their hot, spatially-extended circumgalactic
medium (CGM), despite the ejective activity of their supermassive black holes.
According to TNG-Cluster, the CGM of these gaseous satellites can be seen in
soft X-ray emission (0.5-2.0 keV) that is times brighter than the
local background. This X-ray surface brightness excess around satellites
extends to kpc, and is strongest for galaxies with higher stellar
masses and larger host-centric distances. Approximately 10 per cent of the soft
X-ray emission in cluster outskirts originates from
satellites. The CGM of member galaxies reflects the dynamics of
cluster-satellite interactions and contributes to the observationally-inferred
properties of the intracluster medium.Comment: Submitted to A&A, comments welcome. See companion papers by Nelson et
al., Lehle et al., Truong et al., Lee et al., and Ayromlou et al., and see
the TNG-Cluster website at www.tng-project.org/cluster
Introducing the TNG-Cluster Simulation: overview and physical properties of the gaseous intracluster medium
We introduce the new TNG-Cluster project, an addition to the IllustrisTNG
suite of cosmological magnetohydrodynamical simulations of galaxy formation.
Our objective is to significantly increase the statistical sampling of the most
massive and rare objects in the Universe: galaxy clusters with log(M_200c /
Msun) > 14.3 - 15.4 at z=0. To do so, we re-simulate 352 cluster regions drawn
from a 1 Gpc volume, thirty-six times larger than TNG300, keeping entirely
fixed the IllustrisTNG physical model as well as the numerical resolution. This
new sample of hundreds of massive galaxy clusters enables studies of the
assembly of high-mass ellipticals and their supermassive black holes (SMBHs),
brightest cluster galaxies (BCGs), satellite galaxy evolution and environmental
processes, jellyfish galaxies, intracluster medium (ICM) properties, cooling
and active galactic nuclei (AGN) feedback, mergers and relaxedness, magnetic
field amplification, chemical enrichment, and the galaxy-halo connection at the
high-mass end, with observables from the optical to radio synchrotron and the
Sunyaev-Zeldovich (SZ) effect, to X-ray emission, as well as their cosmological
applications. We present an overview of the simulation, the cluster sample,
selected comparisons to data, and a first look at the diversity and physical
properties of our simulated clusters and their hot ICM.Comment: Submitted to A&A. See companion papers today (Ayromlou, Lee, Lehle,
Rohr, Truong). Additional information and visuals are available on the
TNG-Cluster website at https://www.tng-project.org/cluster
Jellyfish galaxies with the IllustrisTNG simulations – When, where, and for how long does ram pressure stripping of cold gas occur?
Jellyfish galaxies are prototypical examples of satellite galaxies undergoing strong ram pressure stripping (RPS). We analyze the evolution of 512 unique, first-infalling jellyfish galaxies from the TNG50 cosmological simulation. These have been visually inspected to be undergoing RPS sometime in the past 5 billion years (since z = 0.5), have satellite stellar masses , and live in hosts with M200c ∼ 1012 − 14.3 M⊙ at z = 0. We quantify the cold gas (T ≤ 104.5 K) removal using the tracer particles, confirming that for these jellyfish, RPS is the dominant driver of cold gas loss after infall. Half of these jellyfish are completely gas-less by z = 0, and these galaxies have earlier infall times and smaller satellite-to-host mass ratios than their gaseous counterparts. RPS can act on jellyfish galaxies over long time scales of ≈1.5 − 8 Gyr. Jellyfish in more massive hosts are impacted by RPS for a shorter time span and, at a fixed host mass, jellyfish with less cold gas at infall and lower stellar masses at z = 0 have shorter RPS time spans. While RPS may act for long periods of time, the peak RPS period – where at least 50 per cent of the total RPS occurs – begins within ≈1 Gyr of infall and lasts ≲ 2 Gyr. During this period, the jellyfish are at host-centric distances ∼0.2 − 2R200c, illustrating that much of RPS occurs at large distances from the host galaxy. Interestingly, jellyfish continue forming stars until they have lost ≈98 per cent of their cold gas. For groups and clusters in TNG50 , jellyfish galaxies deposit more cold gas (∼1011 − 12 M⊙) into halos than exist in them at z = 0, demonstrating that jellyfish, and in general satellite galaxies, are a significant source of cold gas accretion
X-ray inferred kinematics of the core ICM in Perseus-like clusters: insights from the TNG-Cluster simulation
The intracluster medium (ICM) of galaxy clusters encodes the impact of the
physical processes that shape these massive halos, including feedback from
central supermassive black holes (SMBHs). In this study we examine the gas
thermodynamics, kinematics, and the effects of SMBH feedback on the core of
Perseus-like galaxy clusters with a new simulation suite: TNG-Cluster. We first
make a selection of simulated clusters similar to Perseus based on total mass
and inner ICM properties, i.e. cool-core nature. We identify 30 Perseus-like
systems among the 352 TNG-Cluster halos at . Many exhibit thermodynamical
profiles and X-ray morphologies with disturbed features such as ripples,
bubbles and shock fronts that are qualitatively similar to X-ray observations
of Perseus. To study observable gas motions, we generate XRISM mock X-ray
observations and conduct a spectral analysis of the synthetic data. In
agreement with existing Hitomi measurements, TNG-Cluster predicts subsonic gas
turbulence in the central regions of Perseus-like clusters, with a typical
line-of-sight velocity dispersion of 200 km/s. This implies that turbulent
pressure contributes to the dominant thermal pressure. In TNG-Cluster,
such low (inferred) values of ICM velocity dispersion coexist with
high-velocity outflows and bulk motions of relatively small amounts of
super-virial hot gas, moving up to thousands of km/s. However, detecting these
outflows observationally may prove challenging due to their anisotropic nature
and projection effects. Driven by SMBH feedback, such outflows are responsible
for many morphological disturbances in the X-ray maps of cluster cores. They
also increase both the inferred, and intrinsic, ICM velocity dispersion. This
effect is somewhat stronger when velocity dispersion is measured from
higher-energy lines.Comment: 14 pages, 8 figures. Submitted to A&A, comments welcome. See the
TNG-Cluster website at www.tng-project.org/cluster
An Atlas of Gas Motions in the TNG-Cluster Simulation: from Cluster Cores to the Outskirts
Galaxy clusters are unique laboratories for studying astrophysical processes
and their impact on gas kinematics. Despite their importance, the full
complexity of gas motion within and around clusters remains poorly known. This
paper is part of a series presenting first results from the new TNG-Cluster
simulation, a suite of 352 massive clusters including the full cosmological
context, mergers, accretion, baryonic processes, feedback, and magnetic fields.
Studying the dynamics and coherence of gas flows, we find that gas motions in
cluster cores and intermediate regions are largely balanced between inflows and
outflows, exhibiting a Gaussian distribution centered at zero velocity. In the
outskirts, even the net velocity distribution becomes asymmetric, featuring a
double peak where the second peak reflects cosmic accretion. Across all cluster
regions, the resulting net flow distribution reveals complex gas dynamics.
These are strongly correlated with halo properties: at a given total cluster
mass, unrelaxed, late-forming halos with less massive black holes and lower
accretion rates exhibit a more dynamic behavior. Our analysis shows no clear
relationship between line-of-sight and radial gas velocities, suggesting that
line-of-sight velocity alone is insufficient to distinguish between inflowing
and outflowing gas. Additional properties, such as temperature, can help break
this degeneracy. A velocity structure function (VSF) analysis indicates more
coherent gas motion in the outskirts and more disturbed kinematics towards halo
centers. In all cluster regions, the VSF shows a slope close to the theoretical
models of Kolmogorov (1/3), except within 50 kpc of the cluster cores, where
the slope is significantly steeper. The outcome of TNG-Cluster broadly aligns
with observations of the VSF of multiphase gas across different scales in
galaxy clusters, ranging from 1 kpc to Megaparsec scales.Comment: Submitted to A&A. See the TNG-Cluster website at
https://www.tng-project.org/cluster
MUSE-ALMA Haloes IX: Morphologies and Stellar Properties of Gas-rich Galaxies
Understanding how galaxies interact with the circumgalactic medium (CGM)
requires determining how galaxies morphological and stellar properties
correlate with their CGM properties. We report an analysis of 66 well-imaged
galaxies detected in HST and VLT MUSE observations and determined to be within
500 km s of the redshifts of strong intervening quasar absorbers at
with H I column densities
. We present the geometrical properties (S\'ersic
indices, effective radii, axis ratios, and position angles) of these galaxies
determined using GALFIT. Using these properties along with star formation rates
(SFRs, estimated using the H or [O II] luminosity) and stellar masses
( estimated from spectral energy distribution fits), we examine
correlations among various stellar and CGM properties. Our main findings are as
follows: (1) SFR correlates well with , and most absorption-selected
galaxies are consistent with the star formation main sequence (SFMS) of the
global population. (2) More massive absorber counterparts are more centrally
concentrated and are larger in size. (3) Galaxy sizes and normalized impact
parameters correlate negatively with , consistent with higher
absorption arising in smaller galaxies, and closer to galaxy
centers. (4) Absorption and emission metallicities correlate with and
sSFR, implying metal-poor absorbers arise in galaxies with low past star
formation and faster current gas consumption rates. (5) SFR surface densities
of absorption-selected galaxies are higher than predicted by the
Kennicutt-Schmidt relation for local galaxies, suggesting a higher star
formation efficiency in the absorption-selected galaxies.Comment: Accepted for publication in MNRAS, 25 pages, 19 figure