Merger Dynamics of the Pair of Galaxy Clusters -- A399 and A401

Abstract

Convincing evidence of a past interaction between two rich clusters A399 and A401 was recently found by the X-ray imaging observations. In this paper we examine the structure and dynamics of this pair of galaxy clusters. A mixture-modeling algorithm has been applied to obtain a robust partition into two clusters, which allows us to discuss the virial mass and velocity distribution for each cluster. Assuming that these two clusters follow a linear orbit and they have once experienced a close encounter, we model the binary cluster as a two-body system. As a result, four gravitationally bound solutions are obtained. The recent X-ray observations seem to favor a scenario in which the two clusters with a true separation of $5.4h^{-1}$ Mpc are currently expanding at 583 km/s along the direction with a projection angle of 67.5 degree, and they will reach a maximum extent of $5.65h^{-1}$ Mpc in about $1.0h^{-1}$ Gyr.

arXiv comment11 pages, including 6 EPS figures and 4 tables, uses chjaa.cls, Accepted by the ChJAA

References in corpus (6)

• Detecting Bimodality in Astronomical Datasets
• The Temperature Structure of 30 Nearby Clusters Observed with ASCA. Similarity of Temperature Profiles
• Structure and Dynamics of the Coma Cluster
• XMM-Newton observations of the binary cluster system Abell 399/401
• The X-ray Structure of A399 and A401: A Pre-Merging Cluster Pair
• XMM-Newton observation of the interacting cluster Abell 3528

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• The dynamical status of the galaxy cluster Abell 115
• On the Origin of Cool Core Galaxy Clusters: Comparing X-Ray Observations with Numerical Simulations
• The Double Galaxy Cluster Abell 2465 I. Basic Properties: Optical Imaging and Spectroscopy
• A high-resolution view of the filament of gas between Abell 399 and Abell 401 from the Atacama Cosmology Telescope and MUSTANG-2