2024/08/21 by Tonegawa, Motonari, Okumura, Teppei, Hayashi, Masao · 1 citation
#Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2408.11462
Galaxies are known to be aligned toward specific directions within the large-scale structure. Such alignment signals become important for controlling the systematics of weak lensing surveys and for constraining galaxy formation and evolution scenarios. We measure the galaxy-ellipticity and ellipticity-ellipticity correlation functions for blue star-forming galaxies at z=1.19 and z=1.47 that are selected by detecting [OII] emission lines in narrow-band filters of the Hyper Suprime-Cam on the Subaru Telescope. Assuming that disk galaxies are thin and rotation-supported, we also measure the spin correlation function by estimating spin directions with ellipticities and position angles. Above 1 h-1\rm Mpc, we do not find significant signals for galaxy-ellipticity, ellipticity-ellipticity, or spin correlations at both redshifts. Below 1 h-1\rm Mpc, a weak deviation from zero is seen at z=1.47, implying weak spin-filament correlations, but it is not verified by the direct comparison between angles of spins and filaments. The linear alignment model fit yields the amplitude parameter A\rm NLA=1.38±2.32 at z=1.19 and 0.45±2.09 at z=1.47 (95% confidence levels). We discuss various observational and physical origins that affect the search for alignments of disk galaxies at high redshifts.