S20B0095abst
S20B0095
Our recent MOIRCS NB(Hα) imaging survey of a Planck-selected, starbursting cluster candidate at z=2.16 (PHzG237) successfully revealed a strong over-density of Hα emitters (HAEs). This is the first observational evidence reporting the physical association between “normal" star-forming (SF) galaxies and a Planck-selected dusty cluster in the early universe. We here propose MOIRCS (H+K) follow-up spectroscopy to study the nature of these normal galaxies surviving in this extreme environment. By targeting all major rest-optical emission lines (Hβ/[Oiii]/Hα/[Nii]) of ∼30 HAEs, our science goals are: (1) to map the 3-D structures and determine the dynamical mass of the cluster, to quantify the cluster mass normalized SFRs (ΣSFR/Mcl); (2) to measure the dust attenuation levels of HAEs using the Hα/Hβ ratio, to understand the reason behind the surprisingly large difference between the Hα- and IR-based cluster total SFRs; (3) to determine the gas-phase metallicity of HAEs using [Nii]/Hα ratio, and to quantify the AGN contribution in the starbursting cluster by drawing BPT diagram. The proposed MOIRCS spectroscopy will provide us with a pioneering dataset to unveil the nature of young cluster galaxies experiencing accelerated galaxy growth in extreme environments in the early universe.
This document was translated from LATEX by HEVEA.