Related papers: Lopsided Spiral Galaxies
The warps in many spiral galaxies are now known to asymmetric. Recent sensitive observations have revealed that asymmetry of warps may be the norm rather than exception. However there exists no generic mechanism to generate these…
Some 30% of disc galaxies have a pronounced central bar feature in the disc plane and many more have weaker features of a similar kind. Kinematic data indicate that the bar constitutes a major non-axisymmetric component of the mass…
We present results of numerical N-body simulations of a galactic stellar disk embedded into a spherical dark halo. The non-linear dynamics of bending instabilities developing in the disk is studied. The bending modes, axisymmetric and not,…
In the past decade, an asymmetry in the large-scale distribution of galaxy spin directions has been observed in data from all relevant digital sky surveys, all showing a higher number of galaxies rotating in the opposite direction relative…
This article summarizes recent work on the luminosity and mass distribution of the Galactic bulge and disk, and on the mass of the Milky Way's dark halo. A new luminosity model consistent with the COBE NIR data and the apparent magnitude…
The spatial distribution of satellite galaxies around pairs of galaxies in the Sloan Digital Sky Survey (SDSS) have been found to bulge significantly towards the respective partner. Highly anisotropic, planar distributions of satellite…
Deep HI observations of the outer parts of disc galaxies demonstrate the frequent presence of extended, well-developed spiral arms far beyond the optical radius. To understand the nature and the origin of such outer spiral structure, we…
Stars and their kinematics provide one of the tools available for studies of the shapes of galaxies and their halos. In this review I focus on two specific applications: the shape of the Milky Way dark halo and the shape of the LMC disk.…
Recent observations using several different telescopes and sky surveys showed patterns of asymmetry in the distribution of galaxies by their spin directions as observed from Earth. These studies were done with data imaged from the Northern…
The properties and star formation processes in the far-outer disks of nearby spiral and dwarf irregular galaxies are reviewed. The origin and structure of the generally exponential profiles in stellar disks is considered to result from…
We have conducted a study of optical and HI properties of spiral galaxies (size, luminosity, H-alpha flux distribution, circular velocity, HI gas mass) to investigate causes (e.g., nature versus nurture) for variation within the cluster…
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…
The stellar disks of many spiral galaxies are twice as large as generally thought. We use archival data from the Galaxy Evolution Explorer mission (GALEX) to quantify the statistical properties of young stellar clusters in the outer,…
The severity of the mass discrepancy in spiral galaxies is strongly correlated with the central surface brightness of the disk. Progressively lower surface brightness galaxies have ever larger mass discrepancies. No other parameter…
We have considered polar ring galaxy candidates, the images of which can be found in the SDSS. The sample of 78 galaxies includes the most reliable candidates from the SPRC and PRC catalogs, some of which already have kinematic…
We find that satellites of isolated disk galaxies at projected radii between 300 and 500 kpc are distributed asymmetrically about the parent galaxy and aligned preferentially with the disk minor axis. The dynamical timescale at these radii…
We considered five galaxies in the MaNGA survey that show distinct azimuthal asymmetry in the abundance, in the sense that in the inner part (more than half of the optical radius, $R_{25}$) of each galaxy there is a sector-like region where…
Galaxies are not randomly distributed across the universe but showing different kinds of alignment on different scales. On small scales satellite galaxies have a tendency to distribute along the major axis of the central galaxy, with…
We consider seven distant galaxies with clearly evident spiral structure from HST images. Three of these were chosen from Vogt et al. (1996) (VFP) and have measured rotational velocities. Five were chosen from the Medium Deep Survey and are…
Aims: Using a sample of 175 low-inclination galaxies from the S$^{4}$G, we investigate the origins of up-bending (Type III) breaks in the 3.6 $\mu$m surface brightness profiles of disk galaxies. Methods: We re-analyze a sample of previously…