TY - JOUR
T1 - The ATLAS3D project - XXVI. H I discs in real and simulated fast and slow rotators
AU - Serra, Paolo
AU - Oser, Ludwig
AU - Krajnović, Davor
AU - Naab, Thorsten
AU - Oosterloo, Tom
AU - Morganti, Raffaella
AU - Cappellari, Michele
AU - Emsellem, Eric
AU - Young, Lisa M.
AU - Blitz, Leo
AU - Davis, Timothy A.
AU - Duc, Pierre-Alain
AU - Hirschmann, Michaela
AU - Weijmans, Anne-Marie
AU - Alatalo, Katherine
AU - Bayet, Estelle
AU - Bois, Maxime
AU - Bournaud, Frédéric
AU - Bureau, Martin
AU - Crocker, Alison F.
AU - Davies, Roger L.
AU - de Zeeuw, P. T.
AU - Khochfar, Sadegh
AU - Kuntschner, Harald
AU - Lablanche, Pierre-Yves
AU - McDermid, Richard M.
AU - Sarzi, Marc
AU - Scott, Nicholas
PY - 2014/11
Y1 - 2014/11
N2 - One quarter of all nearby early-type galaxies (ETGs) outside Virgo host
a disc/ring of H I with size from a few to tens of kpc and mass up to
˜109 M⊙. Here we investigate whether
this H I is related to the presence of a stellar disc within the host
making use of the classification of ETGs in fast and slow rotators
(FR/SR). We find a large diversity of H I masses and morphologies within
both families. Surprisingly, SRs are detected as often, host as much H I
and have a similar rate of H I discs/rings as FRs. Accretion of H I is
therefore not always linked to the growth of an inner stellar disc. The
weak relation between H I and stellar disc is confirmed by their
frequent kinematical misalignment in FRs, including cases of polar and
counterrotating gas. In SRs the H I is usually polar. This complex
picture highlights a diversity of ETG formation histories which may be
lost in the relative simplicity of their inner structure and emerges
when studying their outer regions. We find that Λ CDM
hydrodynamical simulations have difficulties reproducing the H I
properties of ETGs. The gas discs formed in simulations are either too
massive or too small depending on the star formation feedback
implementation. Kinematical misalignments match the observations only
qualitatively. The main point of conflict is that nearly all simulated
FRs and a large fraction of all simulated SRs host corotating H I. This
establishes the H I properties of ETGs as a novel challenge to
simulations.
AB - One quarter of all nearby early-type galaxies (ETGs) outside Virgo host
a disc/ring of H I with size from a few to tens of kpc and mass up to
˜109 M⊙. Here we investigate whether
this H I is related to the presence of a stellar disc within the host
making use of the classification of ETGs in fast and slow rotators
(FR/SR). We find a large diversity of H I masses and morphologies within
both families. Surprisingly, SRs are detected as often, host as much H I
and have a similar rate of H I discs/rings as FRs. Accretion of H I is
therefore not always linked to the growth of an inner stellar disc. The
weak relation between H I and stellar disc is confirmed by their
frequent kinematical misalignment in FRs, including cases of polar and
counterrotating gas. In SRs the H I is usually polar. This complex
picture highlights a diversity of ETG formation histories which may be
lost in the relative simplicity of their inner structure and emerges
when studying their outer regions. We find that Λ CDM
hydrodynamical simulations have difficulties reproducing the H I
properties of ETGs. The gas discs formed in simulations are either too
massive or too small depending on the star formation feedback
implementation. Kinematical misalignments match the observations only
qualitatively. The main point of conflict is that nearly all simulated
FRs and a large fraction of all simulated SRs host corotating H I. This
establishes the H I properties of ETGs as a novel challenge to
simulations.
KW - ISM: kinematics and dynamics
KW - galaxies: elliptical and lenticular
KW - cD
KW - galaxies: evolution
KW - galaxies: formation
KW - galaxies: kinematics and dynamics
UR - http://adsabs.harvard.edu/abs/2014MNRAS.444.3388S
U2 - 10.1093/mnras/stt2496
DO - 10.1093/mnras/stt2496
M3 - Article
VL - 444
SP - 3388
EP - 3407
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
ER -