Relative distribution of dark matter, gas, and stars around cosmic
  filaments in the IllustrisTNG simulation
  We present a comprehensive study of the distribution of matter around
different populations of large-scale cosmic filaments, using the IllustrisTNG
simulation at z=0. We computed the dark matter (DM), gas, and stellar radial
density profiles of filaments, and we characterise the distribution of the
baryon fraction in these structures. We find that baryons exactly follow the
underlying DM distribution only down to r~7 Mpc to the filament spines. At
shorter distances (r<7 Mpc), the baryon fraction profile of filaments departs
from the cosmic value $\Omega_\mathrm{b} / \Omega_\mathrm{m}$. While in the
r~0.7-7 Mpc radial domain this departure is due to the radial accretion of the
warm-hot intergalactic medium (WHIM) towards the filament cores (creating an
excess of baryons with respect to the cosmic fraction), the cores of filaments
(r<0.7 Mpc) show a clear baryon depletion instead. The analysis of the
efficiency of active galactic nuclei (AGN) feedback events in filaments reveals
that they are potentially powerful enough to eject gas outside of the
gravitational potential wells of filaments. We show that the large-scale
environment (i.e. denser versus less dense, hotter versus colder regions) has a
non-negligible effect on the absolute values of the DM, gas, and stellar
densities around filaments. Nevertheless, the relative distribution of baryons
with respect to the underlying DM density field is found to be independent of
the filament population. Finally, we provide scaling relations between the gas
density, temperature, and pressure for the different populations of cosmic
filaments. We compare these relations to those pertaining to clusters of
galaxies, and find that these cosmic structures occupy separate regions of the
density-temperature and density-pressure planes.
