The fate of disk galaxies in IllustrisTNG clusters. (arXiv:2004.01191v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_G/0/1/0/all/0/1">Gandhali D. Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pillepich_A/0/1/0/all/0/1">Annalisa Pillepich</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nelson_D/0/1/0/all/0/1">Dylan Nelson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marinacci_F/0/1/0/all/0/1">Federico Marinacci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Springel_V/0/1/0/all/0/1">Volker Springel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rodriguez_Gomez_V/0/1/0/all/0/1">Vicente Rodriguez-Gomez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vogelsberger_M/0/1/0/all/0/1">Mark Vogelsberger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernquist_L/0/1/0/all/0/1">Lars Hernquist</a>
We study the stellar morphological evolution of disk galaxies within clusters
in the TNG50 and TNG100 runs from the IllustrisTNG simulation suite. We select
satellites of masses $10^{9.7}<=M_{*,z=0}/M_{sun}<=10^{11.6}$ residing in
clusters of total masses $10^{14}<=M_{text{200c,z=0}}/M_{sun}<10^{14.6}$ at
z=0 and study those that were disks at accretion according to a kinematic
morphology indicator (the circularity fraction). The galaxies’ histories are
traced from the time of accretion to $z=0$ and compared to a control sample of
central galaxies mass-matched at the time of accretion. Most cluster disks
become non-disky by z=0, in stark contrast with the control disks, of which a
significant fraction remains disky over the same timescales. The transformation
to non-disky morphologies is accompanied by gas removal and star formation
quenching for both cluster and control galaxies. However, cluster disks that
become non-disky by z=0 have lost dark matter (DM) mass and show little growth
or a loss of stellar mass, whereas the corresponding control disks show
significant growth in both components. Most cluster satellites change their
morphologies on similar timescales regardless of stellar mass, in ~0.5-4 Gyr
after accretion. Cluster disks that have had more numerous and closer
pericentric passages show the largest change in morphology. Morphological
change in both cluster and control disks requires the presence of a
gravitational perturbation to drive stellar orbits to non-disky configurations,
along with gas removal/heating to prevent replenishment of the disk through
continued star-formation. For cluster disks, the perturbation is in the form of
impulsive tidal shocking at pericentres and not tidal stripping of the outer
disk stellar material, whereas for control disks, a combination of mergers and
AGN feedback appears to be the key driving force behind morphological
transformations.
We study the stellar morphological evolution of disk galaxies within clusters
in the TNG50 and TNG100 runs from the IllustrisTNG simulation suite. We select
satellites of masses $10^{9.7}<=M_{*,z=0}/M_{sun}<=10^{11.6}$ residing in
clusters of total masses $10^{14}<=M_{text{200c,z=0}}/M_{sun}<10^{14.6}$ at
z=0 and study those that were disks at accretion according to a kinematic
morphology indicator (the circularity fraction). The galaxies’ histories are
traced from the time of accretion to $z=0$ and compared to a control sample of
central galaxies mass-matched at the time of accretion. Most cluster disks
become non-disky by z=0, in stark contrast with the control disks, of which a
significant fraction remains disky over the same timescales. The transformation
to non-disky morphologies is accompanied by gas removal and star formation
quenching for both cluster and control galaxies. However, cluster disks that
become non-disky by z=0 have lost dark matter (DM) mass and show little growth
or a loss of stellar mass, whereas the corresponding control disks show
significant growth in both components. Most cluster satellites change their
morphologies on similar timescales regardless of stellar mass, in ~0.5-4 Gyr
after accretion. Cluster disks that have had more numerous and closer
pericentric passages show the largest change in morphology. Morphological
change in both cluster and control disks requires the presence of a
gravitational perturbation to drive stellar orbits to non-disky configurations,
along with gas removal/heating to prevent replenishment of the disk through
continued star-formation. For cluster disks, the perturbation is in the form of
impulsive tidal shocking at pericentres and not tidal stripping of the outer
disk stellar material, whereas for control disks, a combination of mergers and
AGN feedback appears to be the key driving force behind morphological
transformations.
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