Intrinsic Alignment in redMaPPer clusters -- II. Radial alignment of satellites toward cluster centers

Understand

We study the orientations of satellite galaxies in redMaPPer clusters constructed from the Sloan Digital Sky Survey at $0.1<z<0.35$ to determine whether there is any preferential tendency for satellites to point radially toward cluster centers.

• We analyze the satellite alignment (SA) signal based on three shape measurement methods (re-Gaussianization, de Vaucouleurs, and isophotal shapes), which trace galaxy light profiles at different radii.
• The measured SA signal depends on these shape measurement methods.
• We detect the strongest SA signal in isophotal shapes, followed by de Vaucouleurs shapes.