The Massively Accreting Cluster A2029

Abstract

We explore the structure of galaxy cluster Abell 2029 and its surroundings based on intensive spectroscopy along with X-ray and weak lensing observations. The redshift survey includes 4376 galaxies (1215 spectroscopic cluster members) within 40 arcmin of the cluster center; the redshifts are included here. Two subsystems, A2033 and a Southern Infalling Group (SIG) appear in the infall region based on the spectroscopy as well as on the weak lensing and X-ray maps. The complete redshift survey of A2029 also identifies at least 12 foreground and background systems (10 are extended X-ray sources) in the A2029 field; we include a census of their properties. The X-ray luminosities $L_{X}$ - velocity dispersions ($\\sigma_{cl}$) scaling relations for A2029, A2033, SIG, and the foreground/background systems are consistent with the known cluster scaling relations. The combined spectroscopy, weak lensing, and X-ray observations provide a robust measure of the masses of A2029, A2033, and SIG. The total mass of the infalling groups (A2033 and SIG) is $\\sim 60\\%$ of the M200 of the primary cluster, A2029. Simple dynamical consid- erations suggest that A2029 will accrete these subsystems in next few Gyr. In agreement with simulations and with other clusters observed in a similar redshift range, the total mass in the A2029 infall region is comparable with the A2029 M200 and will mostly be accreted in the long-term future.