TY - JOUR
T1 - The ATLAS(3D) 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 - 2014/3/19
Y1 - 2014/3/19
N2 - One quarter of all nearby early-type galaxies (ETGs) outside Virgo host a disc/ring of HI with size from a few to tens of kpc and mass up to 109M{N-ary circled plus operator} . Here we investigate whether this HI 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 HI masses and morphologies within both families. Surprisingly, SRs are detected as often, host as much HI and have a similar rate of HI discs/rings as FRs. Accretion of HI is therefore not always linked to the growth of an inner stellar disc. The weak relation between HI and stellar disc is confirmed by their frequent kinematical misalignment in FRs, including cases of polar and counterrotating gas. In SRs theHI is usually polar.This complex picture highlights a diversity ofETGformation histories which may be lost in the relative simplicity of their inner structure and emerges when studying their outer regions.We find that CDMhydrodynamical simulations have difficulties reproducing the HI 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 HI. This establishes the HI 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 HI with size from a few to tens of kpc and mass up to 109M{N-ary circled plus operator} . Here we investigate whether this HI 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 HI masses and morphologies within both families. Surprisingly, SRs are detected as often, host as much HI and have a similar rate of HI discs/rings as FRs. Accretion of HI is therefore not always linked to the growth of an inner stellar disc. The weak relation between HI and stellar disc is confirmed by their frequent kinematical misalignment in FRs, including cases of polar and counterrotating gas. In SRs theHI is usually polar.This complex picture highlights a diversity ofETGformation histories which may be lost in the relative simplicity of their inner structure and emerges when studying their outer regions.We find that CDMhydrodynamical simulations have difficulties reproducing the HI 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 HI. This establishes the HI properties of ETGs as a novel challenge to simulations.
KW - cD- galaxies
KW - Elliptical and lenticular
KW - Evolution - galaxies
KW - Formation - galaxies
KW - ISM
KW - Kinematics and dynamics
KW - Kinematics and dynamics - galaxies
UR - http://www.scopus.com/inward/record.url?scp=84922493075&partnerID=8YFLogxK
U2 - 10.1093/mnras/stt2496
DO - 10.1093/mnras/stt2496
M3 - Article
SN - 0035-8711
VL - 444
SP - 3388
EP - 3407
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -