The SAMI galaxy survey: Mass and environment as independent drivers of galaxy dynamics. Issue 2 (15th September 2021)

• Record Type: Journal Article
• Authors: van de Sande, Jesse; Croom, Scott M; Bland-Hawthorn, Joss; Cortese, Luca; Scott, Nicholas; Lagos, Claudia D P; D'Eugenio, Francesco; Bryant, Julia J; Brough, Sarah; Catinella, Barbara; Foster, Caroline; Groves, Brent; Harborne, Katherine E; López-Sánchez, Ángel R; McDermid, Richard; Medling, Anne; Owers, Matt S; Richards, Samuel N; Sweet, Sarah M; Vaughan, Sam P
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 508:Issue 2(2021)
• Page Start: 2307
• Page End: 2328
• Publication Date: 2021-09-15
• Subjects: galaxies: evolution -- galaxies: formation -- galaxies: kinematics and dynamics -- galaxies: stellar content -- galaxies: structure -- cosmology: observations; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab2647
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: 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 $\lambda _{R_{\rm {e}}}$ values, we find that, at fixed mass, satellite galaxies on average have the lowest $\lambda _{\, R_{\rm {e}}, \rm {intr}}$, isolated-central galaxies have the highest $\lambda _{\, R_{\rm {e}}, \rm {intr}}$, and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean $\lambda _{\, R_{\rm {e}}, \rm {intr}}$ values as compared to galaxies at low environmental density. However, at fixed Σ5, the mean $\lambda _{\, R_{\rm {e}}, \rm {intr}}$ differences for low and high-mass galaxies are of similar magnitude as when varying Σ5 ($\Delta \lambda _{\, R_{\rm {e}}, \rm {intr}} \sim 0.05$, with σrandom = 0.025, and σ syst < 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.