How the Galaxy Stellar Spins Acquire a Peculiar Tidal Connection?

Abstract

We explore how the galaxy stellar spins acquire a peculiar tendency of being aligned with the major principal axes of the local tidal fields, in contrast to their DM counterparts which tend to be perpendicular to them, regardless of their masses. Analyzing the halo and subhalo catalogs from the IllustrisTNG 300 hydrodynamic simulations at $z\le 1$, we determine the cosines of the alignment angles, $\cos \alpha$, between the galaxy stellar and DM spins. Creating four $\cos \alpha$-selected samples of the galaxies and then controlling them to share the same density and mass distributions, we determine the average strengths of the alignments between the galaxy stellar spins and the tidal tensor major axes over each sample. It is clearly shown that at $z\le 0.5$ the more severely the galaxy stellar spin directions deviate from the DM counterparts, the stronger the peculiar tidal alignments become. Taking the ensemble averages of such galaxy properties as central blackhole to stellar mass ratio, specific star formation rate, formation epoch, stellar-to-total mass ratio, velocity dispersions, average metallicity, and degree of the cosmic web anisotropy over each sample, we also find that all of these properties exhibit either strong correlations or anti-correlations with $\cos \alpha$. Our results imply that the peculiar tidal alignments of the galaxy stellar spins may be caused by anisotropic occurrence of some baryonic process responsible for discharging stellar materials from the galaxies along the tidal major directions at $z<1$.

arXiv commentaccepted for publication in ApJ, 11 figures, 1 tables, minor revision

References in corpus (38)

• Populating a cluster of galaxies - I. Results at z=0
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• Simulating Galaxy Formation with the IllustrisTNG Model
• First results from the IllustrisTNG simulations: matter and galaxy clustering
• First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies
• First results from the IllustrisTNG simulations: the galaxy color bimodality
• First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium
• How Filaments are Woven into the Cosmic Web
• First results from the IllustrisTNG simulations: radio haloes and magnetic fields
• Dancing in the dark: galactic properties trace spin swings along the cosmic web
• The merger rate of galaxies in the Illustris Simulation: a comparison with observations and semi-empirical models
• The spin and shape of dark matter haloes in the Millennium simulation of a LambdaCDM universe
• Smoothed Particle Hydrodynamics in Astrophysics
• Galaxy alignments: An overview
• The Origin of Disks and Spheroids in Simulated Galaxies
• The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology
• Flux- and volume-limited groups/clusters for the SDSS galaxies: catalogues and mass estimation
• Cosmic Shear from Galaxy Spins
• The alignment and shape of dark matter, stellar, and hot gas distributions in the EAGLE and cosmo-OWLS simulations
• The Large-Scale Orientations of Disk Galaxies
• Angular momentum properties of haloes and their baryon content in the Illustris simulation
• Galaxy orientation with the cosmic web across cosmic time
• The Cosmic Ballet II: Spin alignment of galaxies and haloes with large-scale filaments in the EAGLE simulation
• ZOMG-I. How the cosmic web inhibits halo growth and generates assembly bias
• Reconstructing the cosmic density field with the distribution of dark matter halos
• And yet it flips: connecting galactic spin and the cosmic web
• Cosmic web anisotropy is the primary indicator of halo assembly bias
• The spin alignment of galaxies with the large-scale tidal field in hydrodynamic simulations
• Improving geometric and dynamical constraints on cosmology with intrinsic alignments of galaxies
• Probing Primordial Chirality with Galaxy Spins
• Power Spectrum of Intrinsic Alignments of Galaxies in IllustrisTNG
• The impact of AGN feedback on galaxy intrinsic alignments in the Horizon simulations
• Impact of Baryonic Physics on Intrinsic Alignments
• The Effect of Massive Neutrinos on the Halo Spin Flip Phenomenon
• The Halo Spin Transition as a Probe of Dark Energy
• A sea of tides: star formation and the central-satellite dichotomy in a continuum of tidal environments
• Detection of the Mass-Dependent Dual-Type Transition of Galaxy Spins in IllustrisTNG Simulations
• How the Coherent Tides Obstruct the Radial Infalls of Satellite Galaxies onto Clusters

Cited by in corpus (2)

• Merger Effects on the Spin and Shape Alignments of Galaxy Stellar, Cold and Hot Gas, and Dark Matter Components
• The Density Parity Model for the Evolution of the Subhalo Inner Spin Alignments with the Cosmic Web