Properties of high-redshift passive galaxies: Number density and contribution to the cosmic star formation history
| Main Author: | Emiliano Merlin |
|---|---|
| Format: | info Proceeding |
| Terbitan: |
, 2019
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/3555287 |
Daftar Isi:
- I analyze the properties of the CANDELS passive galaxies at z>3, selected and discussed in Merlin 2018, Santini 2019 and Merlin 2019. The selection on the five CANDELS fields yields a minimal number density of 1.73 - 0.17 x10^-5 Mpc-3 for 3<z<5. I compare these value with those from four hydrodynamical cosmological simulations from the Illustris and Eagle projects, finding a reasonable agreement at z<4; tension arises at earlier epochs. Then, I use the SFHs from the SED-fitting best models to estimate the contribution of the passive candidates to the global Star Formation Rate Density during their previous phase of activity, finding that they account for ~5-10% of the total star formation at 3<z<8, despite being only ~0.5% of the total in number. The resulting overall picture is that early and strong star formation activity, building massive galaxies on short timescales and followed by a quick and abrupt quenching, is a rare but crucial phenomenon in the early Universe.