A Chandra Study of the NGC7618/UGC12491 Major Group Merger at Apogee: Multiple Cold Fronts, Boxy Wings, Filaments, and Arc-shaped Slingshot Tails

Abstract

Analyses of major group mergers are key to understanding the evolution of large-scale structure in the Universe and the microphysical properties of the hot gas in these systems. We present imaging and spectral analyses of deep Chandra observations of hot gas structures formed in the major merger of the NGC 7618 and UGC 12491 galaxy groups and compare the observed hot gas morphology, temperatures, and abundances with recent simulations. The morphology of the observed multiple cold front edges and boxy wings are consistent with those expected to be formed by Kelvin-Helmholtz instabilities and gas sloshing in inviscid gas. The arc-shaped slingshot tail morphologies seen in each galaxy suggest that the dominant galaxies are near their orbital apogee after having experienced at least one core passage at a large impact parameter.

arXiv comment30 pages, 8 figures

References in corpus (47)

• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• Shocks and cold fronts in galaxy clusters
• The 2MASS Redshift Survey - Description and Data Release
• A Textbook Example of a Bow Shock in the Merging Galaxy Cluster 1E0657-56
• A moving cold front in the intergalactic medium of A3667
• The impact of mergers on relaxed X-ray clusters - I. Dynamical evolution and emergent transient structures
• Groups of Galaxies in the Two Micron All-Sky Redshift Survey
• Stirring Up the Pot: Can Cooling Flows In Galaxy Clusters Be Quenched By Gas Sloshing?
• A Sample of 669 Ultra Steep Spectrum Radio Sources to Find High Redshift Radio Galaxies
• Sloshing of the Magnetized Cool Gas in the Cores of Galaxy Clusters
• The MASSIVE Survey IV.: The X-ray halos of the most massive early-type galaxies in the nearby Universe
• The Optical and Near-Infrared Morphologies of Isolated Early Type Galaxies
• Shock heating of the merging galaxy cluster A521
• Infall of the Elliptical Galaxy NGC 1404 into the Fornax Cluster
• Universal X-ray emissivity of the stellar population in early-type galaxies: unresolved X-ray sources in NGC 3379
• A shock at the radio relic position in Abell 115
• Isotropic AGN Heating with Small Radio Quiet Bubbles in the NGC 5044 Group
• Gas sloshing, cold fronts, Kelvin-Helmholtz instabilities and the merger history of the cluster of galaxies Abell 496
• Cold Fronts and Gas Sloshing in Galaxy Clusters with Anisotropic Thermal Conduction
• Chandra Observations of Gas Stripping in the Elliptical Galaxy NGC 4552 in the Virgo Cluster
• Deep Chandra Observations of the Extended Gas Sloshing Spiral in A2029
• The X-ray cavities, filaments and cold fronts in the core of the galaxy group NGC 5044
• Chandra Observation of the Merging Cluster A168: A Late Stage in the Evolution of a Cold Front
• Stripped elliptical galaxies as probes of ICM physics: II. Stirred, but mixed? Viscous and inviscid gas stripping of the Virgo elliptical M89
• The Chandra Fornax Survey - I: The Cluster Environment
• Stripped elliptical galaxies as probes of ICM physics: I. Tails, wakes, and flow patterns in and around stripped ellipticals
• Deep Chandra Observations of Edges and Bubbles in the NGC 5846 Galaxy Group
• Deep Chandra observations of NGC 1404: cluster plasma physics revealed by an infalling early-type galaxy
• Viscous Kelvin-Helmholtz instabilities in highly ionised plasmas
• The Recent Growth History of the Fornax Cluster Derived from Simultaneous Sloshing and Gas Stripping: Simulating the Infall of NGC 1404
• Deep Chandra observations of the stripped galaxy group falling into Abell 2142
• A textbook example of ram-pressure stripping in the Hydra A/A780 cluster
• A Strong Merger Shock in Abell 665
• Sloshing Gas in the Core of the Most Luminous Galaxy Cluster RXJ1347.5-1145
• The impact of sloshing on the intra-group medium and old radio lobe of NGC 5044
• Sloshing cold fronts in galaxy groups and their perturbing disk galaxies: an X-ray, Optical and Radio Case Study
• Irregular sloshing cold fronts in the nearby merging groups NGC 7618 and UGC 12491: evidence for Kelvin-Helmholtz instabilities
• A New Class of X-Ray Tails of Early-Type Galaxies and Subclusters in Galaxy Clusters - Slingshot Tails vs Ram Pressure Stripped Tails
• The Mysterious Merger of NGC6868 and NGC6861 in the Telescopium Group
• The bow shock, cold fronts and disintegrating cool core in the merging galaxy group RXJ0751.3+5012
• Probing the Curious Case of a Galaxy Cluster Merger in Abell 115 with High Fidelity Chandra X-ray Temperature and Radio Maps
• The complex X-ray morphology of NGC 7618: A major group-group merger in the local Universe?
• Stripped elliptical galaxies as probes of ICM physics: III. Deep Chandra Observation of NGC 4552 - Measuring the Viscosity of the Intracluster Medium
• Capturing the 3D Motion of an Infalling Galaxy via Fluid Dynamics
• Building a cluster: shocks, cavities, and cooling filaments in the group-group merger NGC 6338
• The Infall of the Virgo Elliptical Galaxy M60 toward M87 and the Gaseous Structures Produced by Kelvin-Helmholtz Instabilities
• Merger Hydrodynamics of the Luminous Cluster RXJ1347.5-1145

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• Imaging-spectroscopy diagnosis of the giant sloshing spiral in the Virgo cluster with the Einstein Probe Follow-up X-ray Telescope