Subaru/MOIRCS Near-Infrared Imaging in the Proto-Cluster Region at z=3.1

TL;DR

This study uses deep near-infrared imaging to explore galaxy distribution and properties around Ly alpha blobs in a z=3.1 proto-cluster, revealing correlations between stellar mass, galaxy density, and LAB luminosity.

Contribution

It provides new insights into the spatial distribution and stellar mass of galaxies near LABs in a high-redshift proto-cluster using near-infrared imaging.

Findings

Marginal density excess of DRGs and photo-z selected objects around LABs.

Presence of galaxies with stellar mass 10^9-10^11 M_solar near LABs.

Most LABs have plausible K-band counterparts, with stellar mass correlating with LAB luminosity.

Abstract

We present the results of deep near-infrared imaging observations of the z=3.1 proto-cluster region in the SSA22a field taken by MOIRCS mounted on the Subaru Telescope. We observed a 21.7 arcmin^2 field to the depths of J=24.5, H=24.3, and K=23.9 (5 sigma). We examine the distribution of the K-selected galaxies at z~3 by using the simple color cut for distant red galaxies (DRGs) as well as the photometric-redshift selection technique. The marginal density excess of DRGs and the photo-z selected objects are found around the two most luminous Ly alpha blobs (LABs). We investigate the correlation between the K-selected objects and the LABs, and find that several galaxies with stellar mass M_* = 10^9-10^11 M_solar exist in vicinity of LABs, especially around the two most luminous ones. We also find that 7 of the 8 LABs in the field have plausible K_s-band counterparts and the sum of the stellar mass possibly associated with LABs correlates with the luminosity and surface brightness of them, which implies that the origin of Ly alpha emission may be closely correlated with their stellar mass or their previous star formation phenomena.