A spectroscopic survey of Abell 1703: is it a rare relaxed cluster hosting a radio halo or a usual merging system?
arXiv:2001.04707 · doi:10.1093/mnras/staa015
Abstract
We present the study of the internal dynamics of the intriguing galaxy cluster Abell 1703, a system hosting a probable giant radio halo whose dynamical status is still controversial. Our analysis is based on unpublished spectroscopic data acquired at the Italian Telescopio Nazionale Galileo and data publicly available in the literature. We also use photometric data from the Sloan Digital Sky Survey. We select 147 cluster members and compute the cluster redshift and the global line-of-sight velocity dispersion km/s. We infer that Abell 1703 is a massive cluster: . The results of our study disagree with the picture of an unimodal, relaxed cluster as suggested by previous studies based on the gravitational lensing analysis and support the view of a perturbed dynamics proposed by recent works based on Chandra X-ray data. The first strong evidence of a dynamically disturbed cluster comes from the peculiarity of the BCG velocity with respect to the first moment of the velocity distribution of member galaxies. Moreover, several statistical tests employed to study the cluster galaxies kinematics find significant evidence of substructure, being Abell 1703 composed by at least two or three subclumps probably caught after the core-core passage. In this observational scenario, the suspected existence of a radio halo in the centre of this cluster is not surprising and well agrees with the theoretical models describing diffuse radio sources in clusters.
15 pages, 13 figures, 5 tables. In press on MNRAS
References in corpus (14)
- Diffuse Radio Emission from Galaxy Clusters
- On the connection between giant radio halos and cluster mergers
- The relation between velocity dispersion and mass in simulated clusters of galaxies: dependence on the tracer and the baryonic physics
- Brightest Cluster Galaxies at the Present Epoch
- Cosmology and Astrophysics from Relaxed Galaxy Clusters I: Sample Selection
- A New Survey for Giant Arcs
- Strong Lensing in Abell 1703: Constraints on the Slope of the Inner Dark Matter Distribution
- The extended ROSAT-ESO Flux Limited X-ray Galaxy Cluster Survey (REFLEX II) IV. X-ray Luminosity Function and First Constraints on Cosmological Parameters
- A giant radio halo in the cool core cluster CL1821+643
- Keck spectroscopic survey of strongly lensed galaxies in Abell 1703: further evidence for a relaxed, unimodal cluster
- Full Lensing Analysis of Abell 1703: Comparison of Independent Lens-Modelling Techniques
- Mpc-scale diffuse radio emission in two massive cool-core clusters of galaxies
- Major Cluster Mergers and the Location of the Brightest Cluster Galaxy
- Studying the late evolution of a radio-loud AGN in a galaxy group with LOFAR