The Variation of Galaxy Morphological Type with the Shear of Environment

Abstract

Recent N-body simulations have shown that the assembly history of galactic halos depend on the density of large-scale environment. It implies that the galaxy properties like age and size of bulge may also vary with the surrounding large-scale structures, which are characterized by the tidal shear as well as the density. By using a sample of 15,882 well-resolved nearby galaxies from the Tully Catalog and the real space tidal field reconstructed from the 2Mass Redshift Survey (2MRS), we investigate the dependence of galaxy morphological type on the shear of large-scale environment where the galaxies are embedded. We first calculate the large scale dimensionless overdensities (d) and the large-scale ellipticities (e) of the regions where the Tully galaxies are located and classify the Tully galaxies according to their morphological types and create subsamples selected at similar value of d but span different ranges in e. We calculate the mean ellipticity, <e>, averaged over each subsample and find a signal of variation of <e> with galaxy morphological type: For the case of 0.5<=d<=1.0, the ellipticals are found to be preferentially located in the regions with low ellipticity. For the case of -0.3<=d<=0.1, the latest-type spirals are found to be preferentially located in the regions with high ellipticity. The null hypothesis that the mean ellipticities of the regions where the ellipticals and the latest type spirals are located are same as the global mean ellipticity averaged over all types is rejected at 3 sigma level when -0.3<=d<=0.1. Yet, no signal of galaxy-shear correlation is found in the highly overdense/underdense regions. The observed trend suggests that the formation epochs of galactic halos might be a function not only of halo mass and large-scale density but also of large-scale shear.

arXiv commentApJ in press, accepted version, analysis improved, new discussion added

References in corpus (21)

• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• How Filaments are Woven into the Cosmic Web
• Galaxy Star-Formation as a Function of Environment in the Early Data Release of the Sloan Digital Sky Survey
• The 2dF Galaxy Redshift Survey: The environmental dependence of galaxy star formation rates near clusters
• The age dependence of halo clustering
• Relationship between environment and the broad-band optical properties of galaxies in the SDSS
• The Morphology-Density Relation in the Sloan Digital Sky Survey
• Halo assembly bias and its effects on galaxy clustering
• Environmental Dependence of Properties of Galaxies in the Sloan Digital Sky Survey
• Internal and Collective Properties of Galaxies in the Sloan Digital Sky Survey
• Evolution and environment of early-type galaxies
• Reconstructed Density and Velocity Fields from the 2MASS Redshift Survey
• Spectroscopic Properties of Void Galaxies in the Sloan Digital Sky Survey
• Tidal Torques and the Orientation of Nearby Disk Galaxies
• Detection of the effect of cosmological large-scale structure on the orientation of galaxies
• The Alignments of the Galaxy Spins with the Real-Space Tidal Field Reconstructed from the Two Mass Redshift Survey
• Empirical distributions of galactic $\lambda$ spin parameters from the SDSS
• The Luminosity, Colour and Morphology dependence of galaxy filaments in the Sloan Digital Sky Survey Data Release Four
• A Dimensional study of Disk Galaxies
• Dependence of Galaxy Shape on Environment in the Sloan Digital Sky Survey
• Exploring star formation using the filaments in the Sloan Digital Sky Survey Data Release Five (SDSS DR5)

Cited by in corpus (18)

• Detecting filamentary pattern in the cosmic web: a catalogue of filaments for the SDSS
• A kinematic classification of the cosmic web
• The velocity shear tensor: tracer of halo alignment
• The density field of the 10k zCOSMOS galaxies
• SDSS-IV MaNGA: environmental dependence of stellar age and metallicity gradients in nearby galaxies
• Past and present cosmic structure in the SDSS DR7 main sample
• Bayesian non-linear large scale structure inference of the Sloan Digital Sky Survey data release 7
• Cosmic Cartography of the Large-Scale Structure with Sloan Digital Sky Survey Data Release 6
• Bayesian analysis of the dynamic cosmic web in the SDSS galaxy survey
• The cosmic web of the Local Universe: cosmic variance, matter content and its relation to galaxy morphology
• Orientation of cosmic web filaments with respect to the underlying velocity field
• Excursion Sets and Non-Gaussian Void Statistics
• Crawling the Cosmic Network: Exploring the Morphology of Structure in the Galaxy Distribution
• Galaxy alignment as a probe of large-scale filaments
• The cosmic web connection to the dark matter halo distribution through gravity
• The Bridge Effect of Void Filaments
• Gravitational Potential Environment of Galaxies: I. Simulation
• A New Perspective on the Large-Scale Tidal Effect on the Galaxy Luminosity and Morphology