We investigate how environment affects satellite galaxies using their location within the projected phase space of their host haloes from the Wang et al.'s group catalogue. Using the Yonsei Zoom-in Cluster Simulations, we derive zones of constant mean infall time Tinf in projected phase space, and catalogue in which zone each observed galaxy falls. Within each zone, we compute the mean observed galaxy properties including specific star formation rate, luminosity-weighted age, stellar metallicity, and [α/Fe] abundance ratio. By comparing galaxies in different zones, we inspect how shifting the mean infall time from recent infallers (Tinf < 3 Gyr) to ancient infallers (Tinf > 5 Gyr) impacts galaxy properties at fixed stellar and halo mass. Ancient infallers are more quenched, and the impact of environmental quenching is visible down to low host masses (≤group masses). Meanwhile, the quenching of recent infallers is weakly dependent on host mass, indicating they have yet to respond strongly to their current environment. [α/Fe] and especially metallicity are less dependent on host mass, but show a dependence on Tinf. We discuss these results in the context of longer exposure times for ancient infallers to environmental effects, which grow more efficient in hosts with a deeper potential well and a denser intracluster medium. We also compare our satellites with a control field sample, and find that even the most recent infallers (Tinf < 2 Gyr) are more quenched than field galaxies, in particular for cluster mass hosts. This supports the role of pre-processing and/or faster quenching in satellites.
Bibliographical noteFunding Information:
AP and GDL acknowledge support by Sonderforschungsbereich SFB 881 ‘The Milky Way System’ (subproject B5 and visitor programme) of the German Research Foundation. AG and SZ acknowledge support by the Istituto Nazionale di Astrofisica (PRIN-SKA 2017 program 1.05.01.88.04). SKY acknowledges support from the Korean National Research Foundation (NRF-2017R1A2A05001116). This study was performed under the umbrella of the joint collaboration between Yonsei University Observatory and the Korean Astronomy and Space Science Institute. The supercomputing time for numerical simulation was kindly provided by Korea Institute of Science and Technology Information (KISTI) (KSC-2014-G2-003), and large data transfer was supported by Korea Research Environment Open Network (KREONET), which is managed and operated by KISTI. We thank the referee and Quan Guo for valuable comments that helped improve this paper.
© 2019 The Author(s).
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science