Testing the rotation versus merger scenario in the galaxy cluster Abell 2107

Abstract

We search for global rotation of the intracluster medium (ICM) in the galaxy cluster Abell 2107, where previous studies have detected rotational motion in the member galaxies with a high significance level. By fitting the centroid of the iron $K_{\alpha }$ line complex at 6.7--6.9 keV rest frame in {\sl Chandra} ACIS-I spectra, we identify the possible rotation axis with the line that maximizes the difference between the emission-weighted spectroscopic redshift measured in the two halves defined by the line itself. Then, we measure the emission-weighted redshift in linear regions parallel to the preferred rotation axis, and find a significant gradient as a function of the projected distance from the rotation axis, compatible with a rotation pattern with maximum tangential velocity ${\mathtt{v}}_{\max }=1380\pm 600$ km/s at a radius ${\lambda }_0\sim 160$ kpc. This result, if interpreted in the framework of hydrostatic equilibrium, as suggested by the regular morphology of Abell 2107, would imply a large mass correction of the order of $\Delta M=(6\pm 4)\times 10^{13}{M}_{\odot }$ at $\sim 160$ kpc, which is incompatible with the cluster morphology itself. A more conservative interpretation may be provided by an unnoticed off-center, head-on collision between two comparable halos. Our analysis confirms the peculiar dynamical nature of the otherwise regular cluster Abell 2107, but is not able to resolve the rotation vs merger scenario, a science case that can be addressed by the next-generation X-ray facilities carrying X-ray bolometers onboard.

arXiv commentTo appear in MNRAS

References in corpus (36)

• On the Absorption of X-rays in the Interstellar Medium
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions
• Chandra sample of nearby relaxed galaxy clusters: mass, gas fraction, and mass-temperature relation
• Cosmological Parameters from Observations of Galaxy Clusters
• Formation of Galaxy Clusters
• The MCXC: a Meta-Catalogue of X-ray detected Clusters of galaxies
• The Quiescent Intracluster Medium in the Core of the Perseus Cluster
• Residual Gas Motions in the Intracluster Medium and Bias in Hydrostatic Measurements of Mass Profiles of Clusters
• A deeper X-ray study of the core of the Perseus galaxy cluster: the power of sound waves and the distribution of metals and cosmic rays
• Cluster Constraints on f(R) Gravity
• On the nature of hydrostatic equilibrium in galaxy clusters
• Non-thermal pressure support in X-COP galaxy clusters
• Every BCG with a strong radio AGN has an X-ray cool core: is the cool core - noncool core dichotomy too simple?
• HeCS-SZ: The Hectospec Survey of Sunyaev-Zeldovich Selected Clusters
• The XMM Cluster Outskirts Project (X-COP): Thermodynamic properties of the Intracluster Medium out to $R_{200}$ in Abell 2319
• X-ray absorption evolution in Gamma-Ray Bursts: intergalactic medium or evolutionary signature of their host galaxies?
• The chemical enrichment of the ICM from hydrodynamical simulations
• Searching for rotating galaxy clusters in SDSS and 2dFGRS
• Morphology parameters: substructure identification in X-ray galaxy clusters
• Constraints on the ICM velocity power spectrum from the X-ray lines width and shift
• Kinetic Sunyaev-Zel'dovich effect from halo rotation
• Kinetic Sunyaev--Zel'dovich effect in rotating galaxy clusters from MUSIC simulations
• Inside a Beehive: the Multiple Merging Processes in the Galaxy Cluster Abell 2142
• A general framework to test gravity using galaxy clusters I: Modelling the dynamical mass of haloes in $f(R)$ gravity
• Measuring redshift through X-ray spectroscopy of galaxy clusters: results from Chandra data and future prospects
• Galaxy cluster's rotation
• Velocity Structure Diagnostics of Simulated Galaxy Clusters
• Rotation of the cluster of galaxies A2107
• Gas rotation in galaxy clusters: signatures and detectability in X-rays
• Searching for bulk motions in the ICM of massive, merging clusters with Chandra CCD data
• A method to search for bulk motions in the ICM with {\sl Chandra} CCD spectra: application to the Bullet cluster
• Chandra Observations of A2670 and A2107: A Comet Galaxy and cDs with Large Peculiar Velocities
• On the coherent rotation of diffuse matter in numerical simulations of galaxy clusters
• A redshift survey of the nearby galaxy cluster Abell 2107: Global rotation of the cluster and its connection to large-scale structures in the universe
• The rotation of Galaxy Clusters

Cited by in corpus (6)

• X-ray analysis of JWST's first galaxy cluster lens SMACS J0723.3-7327
• Constraining the Rotational Kinematic Sunyaev-Zel'dovich Effect in Massive Galaxy Clusters
• Galaxy cluster rotation revealed in the MACSIS simulations with the kinetic Sunyaev-Zeldovich effect
• Dynamics of the galactic component of Abell S1063 and MACS J1206.2$-$0847
• Searching for rotation in X-COP galaxy clusters
• Signatures and bias assessment of rotation in galaxy cluster members