Investigation of the orientation of galaxies in clusters: the importance, methods and results of research

Abstract

Various models of structure formation can account for various aspects of the galaxy formation process on different scales, as well as for various observational features of structures. Thus, the investigation of galaxies orientation constitute a standard test of galaxies formation scenarios since observed variations in angular momentum represent fundamental constraints for any model of galaxy formation. We have improved the method of analysis of the alignment of galaxies in clusters. Now, the method allowed analysis both position angles of galaxy major axes and two angles describing the spatial orientation of galaxies. The distributions of analyzed angles were tested for isotropy by applying different statistical tests. For sample of analyzed clusters we have computed the mean values of analyzed statistics, checking whether they are the same as expected ones in the case of random distribution of analyzed angles. The detailed discussion of this method has been performed. We have shown how to proceed in many particular cases in order to improve the statistical reasoning when analyzing the distribution of the angles in the observational data. Separately, we have compared these new results with those obtained from numerical simulations. We show the powerful of our method on the example of galaxy orientation analysis in 247 Abell rich galaxy clusters. We have found that the orientations of galaxies in analyzed clusters are not random. It means that we genuinely confirmed an existence of the alignment of galaxies in rich Abells' galaxy clusters. This result is independent from the clusters of Bautz-Morgan types.

JCAP Accepted, longer extended version see v1

References in corpus (14)

• Angular momentum-Large-scale structure alignments in LCDM models and the SDSS
• Galaxy orientation with the cosmic web across cosmic time
• Radial Alignment in Simulated Clusters
• The Formation of Polar Disk Galaxies
• Intrinsic alignments in redMaPPer clusters -- I. Central galaxy alignments and angular segregation of satellites
• Time evolution of intrinsic alignments of galaxies
• Intrinsic Alignment in redMaPPer clusters -- II. Radial alignment of satellites toward cluster centers
• Projected alignment of non-sphericities of stellar, gas, and dark matter distributions in galaxy clusters: analysis of the Horizon-AGN simulation
• Alignment between satellite and central galaxies in the SDSS DR7: dependence on large-scale environment
• The distribution of galaxies gravitational field stemming from their tidal interaction
• Seismic diagnostics of solar-like oscillating stars
• The non-Gaussian distribution of galaxies gravitational fields
• Orientation of galaxies in structures
• Spatial Orientation of Spin Vectors of Blue-shifted Galaxies

Cited by in corpus (6)

• The Three Hundred project: shapes and radial alignment of satellite, infalling, and backsplash galaxies
• Non-parametric reconstruction of cosmological observables using Gaussian Processes Regression
• The shape alignment of satellite galaxies in galaxy pairs in SDSS
• New Evidence of the Azimuthal Alignment of Quasars Spin vector in the LQG U1.28, U1.27, U1.11, Cosmologically Explained
• On the Azimuthal Alignment of Quasars Spin Vector in Large Quasar Groups and Cosmic Strings
• The Limits of Photometric Dynamics: Benchmarking Cluster Relaxation Diagnostics