The SAMI Galaxy Survey: Mass and Environment as Independent Drivers of Galaxy Dynamics

• Main 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, Harborne, Brent Groves Katherine E., López-Sánchez, Ángel R., McDermid, Richard, Medling, Anne, Owers, Matt S., Richards, Samuel N., Sweet, Sarah M., Vaughan, Sam P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: arXiv 2021
• Subjects: Astrophysics of Galaxies astro-ph.GA; Cosmology and Nongalactic Astrophysics astro-ph.CO; FOS Physical sciences; sami
• Online Access: https://dx.doi.org/10.48550/arxiv.2109.06189; https://arxiv.org/abs/2109.06189

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 $\sim$1800 early and late-type galaxies with $\log(M_*/M_{\odot})>9.5$ as a function of mean environmental overdensity ($Σ_{5}$) and their rank within a group or cluster. By classifying galaxies into fast and slow rotators, at fixed stellar mass above $\log(M_*/M_{\odot})>10.5$, we detect a higher fraction ($\sim3.4σ$) of slow rotators for group and cluster centrals and satellites as compared to isolated-central galaxies. 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 $λ_{R_e}$ values, we find that, at fixed mass, satellite galaxies on average have the lowest $λ_{\,R_e,intr}$, isolated-central galaxies have the highest $λ_{\,R_e,intr}$, and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean $λ_{\,R_e,intr}$ values as compared to galaxies at low environmental density. However, at fixed $Σ_{5}$, the mean $λ_{\,R_e,intr}$ differences for low and high-mass galaxies are of similar magnitude as when varying $Σ_{5}$ {($Δλ_{\,R_e,intr} \sim 0.05$. 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. : 22 pages and 17 figures, accepted for publication in MNRAS. Abstract abridged for Arxiv. The key figures of the paper are: 6, 8, 10, and 12