相关论文: Only marginal alignment of disc galaxies
Intrinsic alignments are believed to be a major source of systematics for future generation of weak gravitational lensing surveys like Euclid or LSST. Direct measurements of the alignment of the projected light distribution of galaxies in…
We have investigated the pitch angle ($\psi$) of the spiral arms of galaxies in the Hubble Space Telescope COSMOS field. The sample consists of 102 face-on galaxies with a two-armed pattern at a mean redshift $\langle z \rangle \approx…
We describe ongoing work on a new method that allows one to determine the mass and relative position (in galactocentric radius and azimuth) of galactic companions purely from analysis of observed disturbances in gas disks. Here, we…
Galaxy spins are believed to retain the initially acquired tendency of being aligned with the intermediate principal axes of the linear tidal field, which disseminates a prospect of using them as a probe of early universe physics. This…
It has been shown, both in simulations and observationally, that the tidal field of a large galaxy can torque its satellites such that the major axis of satellite galaxies points towards their hosts. This so-called `shape alignment' has…
We demonstrate numerical techniques for automatic identification of individual spiral arms in hydrodynamic simulations of astrophysical discs. Building on our earlier work, which used tensor classification to identify regions that were…
Several recent observations using large datasets of galaxies showed non-random distribution of the spin directions of spiral galaxies, even when the galaxies are too far from each other to have gravitational interaction. Here, a dataset of…
Predicting the local flux of dark matter particles is vital for dark matter direct detection experiments. To date, such predictions have been based on simulations that model the dark matter alone. Here we include the influence of the…
We investigate two possible effects of the tidal field induced by a spherical cluster on its elliptical galaxy members: the modification of the ellipticity of a spherical galaxy and the isophotal alignment in the cluster radial direction of…
This work investigates the alignment of galactic spins with the cosmic web across cosmic time using the cosmological hydrodynamical simulation Horizon-AGN. The cosmic web structure is extracted via the persistent skeleton as implemented in…
It has recently been argued that the observed ellipticities of galaxies may be determined at least in part by the primordial tidal gravitational field in which the galaxy formed. Long-range correlations in the tidal field could thus lead to…
The formation of galactic discs and the efficiency of star formation within them are issues central to our understanding of galaxy formation. We have developed a detailed and versatile model of disc formation which combines the strengths of…
The density-wave theory of galactic spiral-arm structure makes a striking prediction that the pitch angle of spiral arms should vary with the wavelength of the galaxy's image. The reason is that stars are born in the density wave but move…
A significant fraction of galaxies show warps in their discs, usually noticeable at its periphery. The exact origin of this phenomenon is not fully established, although multiple warp formation mechanisms are proposed. In this study, we…
Accurate measurements of the cosmic shear signal require a separation of the true weak gravitational lensing signal from intrinsic shape correlations of galaxies. These `intrinsic alignments' of galaxies originate from galaxy formation…
Spatial correlations between spiral arms and other galactic components such as giant molecular clouds and massive OB stars suggest that spiral arms can play vital roles in various aspects of disk galaxy evolution. Segmentation of spiral…
Stellar radial migration has predominantly been examined in isolated disc galaxies where non-axisymmetric structures drive the process. By contrast, while tidal interactions are known for having an influence, their contribution remains…
We have tested the applicability of the global modal approach in the density wave theory of spiral structure for a sample of spiral galaxies with measured axisymmetric background properties. We report here the results of the simulations for…
The importance of angular momentum in regulating the sizes of galactic disks and by this their star formation history is highlighted. Tidal torques and accretion of satellites in principle provide enough angular momentum to form disks with…
Stars in disks of spiral galaxies are usually assumed to remain roughly at their birth radii. This assumption is built into decades of modelling of the evolution of stellar populations in our own Galaxy and in external systems. We present…