Physics and Astronomy
We explore how the group environment may affect the evolution of star-forming galaxies. We select 1197 Galaxy And Mass Assembly groups at 0.05 ≤ z ≤ 0.2 and analyze the projected phase space (PPS) diagram, i.e., the galaxy velocity as a function of projected group-centric radius, as a local environmental metric in the low-mass halo regime 1012 ≤ (M 200/M o) < 1014. We study the properties of star-forming group galaxies, exploring the correlation of star formation rate (SFR) with radial distance and stellar mass. We find that the fraction of star-forming group members is higher in the PPS regions dominated by recently accreted galaxies, whereas passive galaxies dominate the virialized regions. We observe a small decline in specific SFR of star-forming galaxies toward the group center by a factor ∼1.2 with respect to field galaxies. Similar to cluster studies, we conclude for low-mass halos that star-forming group galaxies represent an infalling population from the field to the halo and show suppressed star formation.
Barsanti, S.; Owers, M. S.; Brough, S.; Davies, L. J.M.; Driver, S. P.; Gunawardhana, M. L.P.; Holwerda, Benne W.; Liske, J.; Loveday, J.; Pimbblet, K. A.; Robotham, A. S.G.; and Taylor, E. N., "Galaxy and mass assembly (gama): Impact of the group environment on galaxy star formation" (2018). Faculty Scholarship. 505.