The Infall of the Virgo Elliptical Galaxy M60 toward M87 and the Gaseous Structures Produced by Kelvin-Helmholtz Instabilities

Abstract

We present Chandra observations of hot gas structures, characteristic of gas stripping during infall, in the Virgo cluster elliptical galaxy M60 (NGC4649) located $1$ Mpc east of M87. $0.5-2$ keV Chandra X-ray images show a sharp leading edge in the surface brightness $12.4\pm 0.1$ kpc north and west of the galaxy center in the direction of M87 characteristic of a merger cold front due to M60's motion through the Virgo ICM. We measured a temperature of $1.00\pm 0.02$ keV for abundance $0.5Z_{\odot }$ inside the edge and $1.37_{-0.19}^{+0.35}$ keV for abundance $0.1Z_{\odot }$ in the Virgo ICM free stream region. We find that the observed jump in surface brightness yields a density ratio of $6.44_{-0.67}^{+1.04}$ between gas inside the edge and in the cluster free stream region. If the edge is a cold front due solely to the infall of M60 in the direction of M87, we find a pressure ratio of $4.7_{-1.4}^{+1.7}$ and Mach number $1.7\pm 0.3$. For 1.37 keV Virgo gas we find a total infall velocity for M60 of $1030\pm 180$ kms${}^{-1}$. We calculate the motion in the plane of the sky to be $1012_{-192}^{+183}$ km${}^{-1}$ implying an inclination angle $\xi =11\pm 3$ degrees. Surface brightness profiles show the presence of a faint diffuse gaseous tail. We identify filamentary, gaseous wing structures caused by the galaxy's motion through the ICM. The structure and dimensions of these wings are consistent with simulations of Kelvin-Helmholtz instabilities as expected if the gas stripping is close to inviscid.

arXiv comment12 pages, 7 figures, added references, discussion of magnetic fields and other minor text changes to conform to published version, results unchanged

References in corpus (22)

• The Optical and Near-Infrared Properties of Galaxies: I. Luminosity and Stellar Mass Functions
• The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances
• Shocks and cold fronts in galaxy clusters
• The ACS Virgo Cluster Survey. XIII. SBF Distance Catalog and the Three-Dimensional Structure of the Virgo Cluster
• The Stellar Population Histories of Local Early-Type Galaxies. I. Population Parameters
• Chandra temperature profiles for a sample of nearby relaxed galaxy clusters
• A moving cold front in the intergalactic medium of A3667
• Low mass X-ray binaries as a stellar mass indicator for the host galaxy
• X-ray Spectroscopy of the Virgo Cluster out to the Virial Radius
• Magnetic draping of merging cores and radio bubbles in clusters of galaxies
• Chandra's View of the Ram Pressure Stripped Galaxy M86
• Infall of the Elliptical Galaxy NGC 1404 into the Fornax Cluster
• Detecting the orientation of magnetic fields in galaxy clusters
• Universal X-ray emissivity of the stellar population in early-type galaxies: unresolved X-ray sources in NGC 3379
• Chandra Observations of Gas Stripping in the Elliptical Galaxy NGC 4552 in the Virgo Cluster
• Impact of magnetic fields on ram pressure stripping in disk galaxies
• 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
• Unresolved and diffuse components of X-ray emission and X/K luminosity ratios in nearby early-type and late-type galaxies
• X-ray emission from the stellar population in M32
• Irregular sloshing cold fronts in the nearby merging groups NGC 7618 and UGC 12491: evidence for Kelvin-Helmholtz instabilities

Cited by in corpus (11)

• Ram Pressure Stripping in High-Density Environments
• Constraining Gas Motions in the Intra-Cluster Medium
• A New Class of X-Ray Tails of Early-Type Galaxies and Subclusters in Galaxy Clusters - Slingshot Tails vs Ram Pressure Stripped Tails
• Chandra Early-Type Galaxy Atlas
• Probing multiphase gas in local massive elliptical galaxies via multiwavelength observations
• A New Method to Constrain the Appearance and Disappearance of Observed Jellyfish Galaxy Tails
• VLA Radio Study of a Sample of Nearby X-ray and Optically Bright Early-Type Galaxies
• A discrete chemo-dynamical model of M87's globular clusters: Kinematics extending to ~ 400 kpc
• X-ray Constraints on the Hot Gas Content of Early-type Galaxies in Virgo
• The Hot Interstellar Medium
• A Chandra Study of the NGC7618/UGC12491 Major Group Merger at Apogee: Multiple Cold Fronts, Boxy Wings, Filaments, and Arc-shaped Slingshot Tails