Star Formation Activity in Confirmed Clusters and Proto-Clusters at 1.4 < z < 2.8
| Main Author: | Noirot, Gaël |
|---|---|
| Format: | info Proceeding |
| Terbitan: |
, 2019
|
| Online Access: |
https://zenodo.org/record/3523016 |
Daftar Isi:
- Radio-loud AGN (RLAGN) tend to reside in the most massive dark matter halos, and have a long history of being used to efficiently identify rich, high-redshift structures (i.e., clusters and proto-clusters). Our team led the “Clusters Around Radio-Loud AGN” (CARLA) survey, which was a 400-hr Spitzer program surveying 420 RLAGN (radio-loud quasars and high-redshift radio galaxies) at 1.3 < z < 3.2 across the full sky. CARLA identified 200 cluster candidates as significant overdensities of red color-selected Spitzer/IRAC galaxies around the RLAGN, which samples the previously largely unexplored transition epoch between proto-cluster and cluster environments (Wylezalek et al. 2013, 2014). I will introduce this high-redshift cluster survey and present results from our follow-up 40-orbit Hubble Space Telescope program of the 20 densest CARLA cluster candidates. We spectroscopically confirm 16 of the 20 distant structures associated with the RLAGN, out to z=2.8 (Noirot et al. 2016, 2018). For the first time at these redshifts, we statistically investigate the star-formation content of a large sample of confirmed members in dense structures. I will show that, by z ~ 2, (proto)cluster environments are already strongly influencing galaxy evolution. Particularly, I will show that 1.4 < z < 2.0 massive member galaxies already followed an accelerated evolution in dense environments at these early epochs. I will also show that at 1.4 < z < 2.0, CARLA cores are the main sites of star formation, consistent with the onset of the reversal in the star formation rate - density relation at z ~ 1.4. This survey represents a unique and large homogenous sample of spectroscopically confirmed structures at high redshifts, ideal to further study galaxy cluster physics, star-formation, quenching mechanisms, and AGN feedback.