Speaker
Description
In the framework of the standard cosmological model, dark matter halos grow by hierarchical clumping. The spatial distribution of satellite galaxies is closely related to the nature of the halo and its accretion history. Firstly, using SDSS and Millennium simulations we study the spatial distribution of satellites in galaxy clusters. We find that the distribution of satellite galaxies is anisotropic, which is related to the host halo, large-scale structure and the anisotropic accretion history of satellites. Then, in SDSS, we find that the satellite galaxy pairs distributed on the opposite side of the primary galaxy, are more likely to have the same sign direction of motion, which means counter-rotating. We find Millennium and IllustrisTNG show discrepancies with the observations at 4.3𝜎 and 4.0𝜎, respectively. Finally, using the MaNGA integral field spectroscopic data and the SDSS galaxy group catalogue, we investigate the alignment between the angular momentum of the central galaxy and the orbital angular momentum of the satellite galaxy. We find a weak signal of alignment for the overall sample; an enhanced signal of alignment for red satellite galaxies in the intermediate-mass galaxy groups.
