研究成果藝廊

Top: Median sSFR of SF galaxies as a function of redshift in the field (dotted), groups (dashed), and clusters (solid). Bottom: The logarithmic ratio of sSFR for group to field galaxies (dashed), and for cluster to field galaxies (solid). At fixed masses, the decrease level is very similar for cluster galaxies or group galaxies in different redshift ranges, and the reduction offset is seen <0.4 dex for clusters and <0.2 dex for groups. That is, the decrease of sSFRs for the group to field galaxies and for the cluster to field ones is independent of redshift, implying an universal slow quenching mechanism acting in the dense environments since z ~ 1.1.