English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

We compare the star formation (SF) activity in cluster galaxies to the fieldfrom z=0.3-1.5 using $Herschel$ SPIRE 250$\mu$m imaging. We utilize 274clusters from the IRAC Shallow Cluster Survey (ISCS) selected as rest-framenear-infrared overdensities over the 9 square degree Bootes field . Thisanalysis allows us to quantify the evolution of SF in clusters over a longredshift baseline without bias against active cluster systems. Using a stackinganalysis, we determine the average star formation rates (SFRs) andspecific-SFRs (SSFR=SFR/M$_{\star}$) of stellar mass-limited (M>1.3x10$^{10}$M$_{\odot}$), statistical samples of cluster and field galaxies, probing boththe star forming and quiescent populations. We find a clear indication that theaverage SF in cluster galaxies is evolving more rapidly than in the field, withfield SF levels at z>1.2 in the cluster cores (r<0.5 Mpc), in good agreementwith previous ISCS studies. By quantifying the SF in cluster and field galaxiesas an exponential function of cosmic time, we determine that cluster galaxiesare evolving ~2 times faster than the field. Additionally, we see enhanced SFabove the field level at z~1.4 in the cluster outskirts (r>0.5 Mpc). Thesegeneral trends in the cluster cores and outskirts are driven by the lower massgalaxies in our sample. Blue cluster galaxies have systematically lower SSFRsthan blue field galaxies, but otherwise show no strong differential evolutionwith respect to the field over our redshift range. This suggests that thecluster environment is both suppressing the star formation in blue galaxies onlong time-scales and rapidly transitioning some fraction of blue galaxies tothe quiescent galaxy population on short time-scales. We argue that our resultsare consistent with both strangulation and ram pressure stripping acting inthese clusters, with merger activity occurring in the cluster outskirts.

The evolution of dust-obscured star formation activity in galaxy clusters relative to the field over the last 9 billion years