Discovery of the kinematic alignment of early-type galaxies in the Virgo cluster

Abstract

Using the kinematic position angles (PA_kin), an accurate indicator for the spin axis of a galaxy, obtained from the ATLAS3D integral-field-unit (IFU) spectroscopic data, we discovered that 57 Virgo early-type galaxies tend to prefer the specific PA_kin values of 20 degree and 100 degree, suggesting that they are kinematically aligned with each other. These kinematic alignment angles are further associated with the directions of the two distinct axes of the Virgo cluster extending east-west and north-south, strongly suggesting that the two distinct axes are the filamentary structures within the cluster as a trace of infall patterns of galaxies. Given that the spin axis of a massive early-type galaxy does not change easily even in clusters from the hydrodynamic simulations, Virgo early-type galaxies are likely to fall into the cluster along the filamentary structures while maintaining their angular momentum. This implies that many early-type galaxies in clusters are formed in filaments via major mergers before subsequently falling into the cluster. Investigating the kinematic alignment in other clusters will allow us to understand the formation of galaxy clusters and early-type galaxies.

Accepted at ApJL, 6pages, 3 figure

References in corpus (12)

• The Extended Virgo Cluster Catalog
• From voids to filaments: environmental transformations of galaxies in the SDSS
• Three Different Types of Galaxy Alignment within Dark Matter Halos
• The alignment of satellite galaxies and cosmic filaments: observations and simulations
• Constraints on the Alignment of Galaxies in Galaxy Clusters from $\sim$14,000 Spectroscopic Members
• Spatial and kinematic alignments between central and satellite halos
• Large-scale filamentary structures around the Virgo cluster revisited
• The effect of cosmic web filaments on the properties of groups and their central galaxies
• Intrinsic alignments in redMaPPer clusters -- I. Central galaxy alignments and angular segregation of satellites
• Alignment of galaxies relative to their local environment in SDSS-DR8
• Ten Billion Years of Brightest Cluster Galaxy Alignments
• Galaxy Orientation and Alignment Effects in the SDSS DR6

Cited by in corpus (6)

• Mysterious Coherence in Several-Megaparsec Scales Between Galaxy Rotation and Neighbor Motion
• Galaxy Rotation Coherent with the Motions of Neighbors: Discovery of Observational Evidence
• Wobbling galaxy spin axes in dense environments
• Filaments of Galaxies as a Clue to the Origin of Ultra-High-Energy Cosmic Rays
• Living with Neighbors. IV. Dissecting the Spin$-$Orbit Alignment of Dark Matter Halos: Interacting Neighbors and the Local Large-scale Structure
• Small-Scale Dynamical Coherence Accompanied with Galaxy Conformity