Detalles de publicación
PP 024029
The effects of environment on galaxies' dynamical structures: From simulations to observations
(1) Shanghai Astronomical Observatory,
(2) School of Astronomy and Space Sciences,
(3) Max-Planck-Institut für Astronomie,
(4) University of Vienna,
(5) Università di Padova,
(6) INAF - Osservatorio Astronomico di Padova,
(7) INAF - Astronomical Observatory of Capodimonte,
(9) Instituto de Astrofísica de Canarias,
(10) Departamento de Astrofísica, Universidad de La Laguna.
We studied the effects of cluster environments on galactic structures by
using the TNG50 cosmological simulation and observed galaxies in the Fornax
cluster. We focused on galaxies with stellar masses of $10^{8-12}M_{\odot}$ at
z=0 that reside in Fornax-like clusters with total masses of $M_{200c} =
10^{13.4-14.3}M_{\odot}$. We characterized the stellar structures by
decomposing each galaxy into a dynamically cold disk and a hot non-disk
component, and studied the evolution of both the stellar and gaseous
constituents. In TNG50, we find that the cold gas is quickly removed when a
galaxy falls into a Fornax-mass cluster. About 87\% of the galaxies have lost
$80\%$ of their star-forming gas at 4 billion years after infall, with the
remaining gas concentrating in the inner regions of the galaxy. The radius of
the star-forming gaseous disk decreases to half its original size at 4 billion
years after infall for 66\% of the galaxies. As a result, star formation in the
extended dynamically cold disk sharply decreases, even though a low level of SF
persists at the center for a few additional gigayears. This leads to a tight
correlation between the average stellar age in the dynamically cold disk and
the infall time of galaxies. Furthermore, the luminosity fraction of the
dynamically cold disk in ancient infallers is only about 1/3 of that in recent
infallers, controlling for galaxy stellar mass. This quantitatively agrees with
what is observed in early-type galaxies in the Fornax cluster. Gas removal
stops the possible growth of the disk, with gas removed earlier in galaxies
that fell in earlier, and hence the cold-disk fraction is correlated with the
infall time. The stellar disk can be significantly disrupted by tidal forces
after infall, through a long-term process that enhances the difference among
cluster galaxies with different infall times.
using the TNG50 cosmological simulation and observed galaxies in the Fornax
cluster. We focused on galaxies with stellar masses of $10^{8-12}M_{\odot}$ at
z=0 that reside in Fornax-like clusters with total masses of $M_{200c} =
10^{13.4-14.3}M_{\odot}$. We characterized the stellar structures by
decomposing each galaxy into a dynamically cold disk and a hot non-disk
component, and studied the evolution of both the stellar and gaseous
constituents. In TNG50, we find that the cold gas is quickly removed when a
galaxy falls into a Fornax-mass cluster. About 87\% of the galaxies have lost
$80\%$ of their star-forming gas at 4 billion years after infall, with the
remaining gas concentrating in the inner regions of the galaxy. The radius of
the star-forming gaseous disk decreases to half its original size at 4 billion
years after infall for 66\% of the galaxies. As a result, star formation in the
extended dynamically cold disk sharply decreases, even though a low level of SF
persists at the center for a few additional gigayears. This leads to a tight
correlation between the average stellar age in the dynamically cold disk and
the infall time of galaxies. Furthermore, the luminosity fraction of the
dynamically cold disk in ancient infallers is only about 1/3 of that in recent
infallers, controlling for galaxy stellar mass. This quantitatively agrees with
what is observed in early-type galaxies in the Fornax cluster. Gas removal
stops the possible growth of the disk, with gas removed earlier in galaxies
that fell in earlier, and hence the cold-disk fraction is correlated with the
infall time. The stellar disk can be significantly disrupted by tidal forces
after infall, through a long-term process that enhances the difference among
cluster galaxies with different infall times.