Bimodal morphologies of massive galaxies at the core of a protocluster at z = 3.09 and the strong size growth of a brightest cluster galaxy

摘要: We present the near-infrared high resolution imaging of an extremely dense group galaxies at core protocluster $z=3.09$ in SSA22 field by using adaptive optics AO188 and Infrared Camera Spectrograph (IRCS) on Subaru Telescope. Wide morphological variety them suggests their on-going dramatic evolutions. One two quiescent (QGs), most massive one group, is a compact elliptical with effective radius $r_{e} = 1.37\pm0.75$ kpc. It supports two-phase formation scenario giant ellipticals today that formed once evolves size stellar mass series mergers. Since this object plausible progenitor brightest cluster galaxy (BCG) clusters today, it requires strong ($\ga10$) ($\sim$ four times $z=0$) growths. Another QG hosts AGN(s) fitted model composed from nuclear component S\'ersic model. shows spatially extended [O{\footnotesize III}]$\lambda$5007 emission line compared to continuum emission, evidence outflows. Massive star forming (SFGs) are three larger than SFGs similar redshift. Although we obtained $K$-band image deeper previous one, found no candidate new members. This implies physical deficiency low $M_{\star}\la4\times10^{10}~M_{\odot}$ and/or poor detection completeness owing diffuse morphologies.