An azimuthally resolved study of the cold front in Abell 3667

Abstract

The microphysical properties, such as effective viscosity and conductivity, of the weakly magnetized intergalactic plasma are not yet well known. We investigate the constraints that can be placed by an azimuthally resolved study of the cold front in Abell 3667 using $\sim$500 ksec archival Chandra data. We find that the radius of the interface fluctuates with position angle and the morphology of the interface is strikingly similar to recent numerical simulations of inviscid gas-stripping. We find multiple edges in the surface brightness profiles across the cold front as well as azimuthal variations, which are consistent with the presence of Kelvin-Helmholtz Instabilities (KHI) developing along the cold front. They indicate that the characteristic length scale of KHI rolls is around 20-80 kpc. This is the first observational indication of developing KHIs along a merger cold front in a galaxy cluster. Based on the KHI scenario, we estimated the upper limit of the ICM effective viscosity. The estimated value of $\mu \lesssim 200g/cm/s$ is at most 5% of the isotropic Spitzer-like viscosity. The observed apparent mixing towards the outer edges away from the tip of the front provides an additional evidence for suppressed viscosity.

accepted for publication in MNRAS

References in corpus (11)

• Shocks and cold fronts in galaxy clusters
• Draping of Cluster Magnetic Fields over Bullets and Bubbles -- Morphology and Dynamic Effects
• Contour binning: a new technique for spatially-resolved X-ray spectroscopy applied to Cassiopeia A
• Magnetic draping of merging cores and radio bubbles in clusters of galaxies
• The growth of the galaxy cluster Abell 85: mergers, shocks, stripping and seeding of clumping
• Stripped elliptical galaxies as probes of ICM physics: II. Stirred, but mixed? Viscous and inviscid gas stripping of the Virgo elliptical M89
• Stripped elliptical galaxies as probes of ICM physics: I. Tails, wakes, and flow patterns in and around stripped ellipticals
• Deep Chandra observations of NGC 1404: cluster plasma physics revealed by an infalling early-type galaxy
• The first Murchison Widefield Array low frequency radio observations of cluster scale non-thermal emission: the case of Abell 3667
• Early Science with the Karoo Array Telescope: a Mini-Halo Candidate in Galaxy Cluster Abell 3667
• How Much Can We Learn From A Merging Cold Front Cluster? : Insights From X-ray Temperature and Radio Maps of Abell 3667

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• Discovery of a >13 Mpc long X-ray filament between two galaxy clusters beyond three times their virial radii
• Indications of an offset merger in Abell 3667
• The Advanced X-ray Imaging Satellite
• Spatio-temporal characterization of Cassiopeia A
• Physics of cosmic plasmas from high angular resolution X-ray imaging of galaxy clusters