Publication Date:
2021-09-15
Description:
The kinematic morphology–density relation of galaxies is normally attributed to a changing distribution of galaxy stellar masses with the local environment. However, earlier studies were largely focused on slow rotators; the dynamical properties of the overall population in relation to environment have received less attention. We use the SAMI Galaxy Survey to investigate the dynamical properties of ∼1800 early and late-type galaxies with log (M⋆/M⊙) 〉 9.5 as a function of mean environmental overdensity (Σ5) and their rank within a group or cluster. By classifying galaxies into fast and slow rotators, at fixed stellar mass above log (M⋆/M⊙) 〉 10.5, we detect a higher fraction (∼3.4σ) of slow rotators for group and cluster centrals and satellites as compared to isolated-central galaxies. We find similar results when using Σ5 as a tracer for environment. Focusing on the fast-rotator population, we also detect a significant correlation between galaxy kinematics and their stellar mass as well as the environment they are in. Specifically, by using inclination-corrected or intrinsic $lambda _{R_{
m {e}}}$ values, we find that, at fixed mass, satellite galaxies on average have the lowest $lambda _{, R_{
m {e}},
m {intr}}$, isolated-central galaxies have the highest $lambda _{, R_{
m {e}},
m {intr}}$, and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean $lambda _{, R_{
m {e}},
m {intr}}$ values as compared to galaxies at low environmental density. However, at fixed Σ5, the mean $lambda _{, R_{
m {e}},
m {intr}}$ differences for low and high-mass galaxies are of similar magnitude as when varying Σ5 ($Delta lambda _{, R_{
m {e}},
m {intr}} sim 0.05$, with σrandom = 0.025, and σsyst 〈 0.03). Our results demonstrate that after stellar mass, environment plays a significant role in the creation of slow rotators, while for fast rotators we also detect an independent, albeit smaller, impact of mass and environment on their kinematic properties.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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