Related papers: Are polar rings indeed polar?
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 use 666 blue horizontal branch (BHB) stars from the 2Qz redshift survey to map the Galactic halo in four dimensions (position, distance and velocity). We find that the halo extends to at least 100 kpc in Galactocentric distance, and…
We performed an integrated optical polarization survey of 70 nearby galaxies to study the relationship between linear polarization and galaxy properties. To date this is the largest survey of its kind. The data were collected at McDonald…
In this article I extend an earlier study of spiral galaxies in the Sloan Digital Sky Survey (SDSS) to investigate whether the universe has an overall handedness. A preference for spiral galaxies in one sector of the sky to be left-handed…
Using imaging data from the SDSS survey, we present the g' and r' radial stellar light distribution of a complete sample of ~90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness profiles…
Disks of bodies orbiting a much more massive central object are extremely common in astrophysics. When the orbits comprising such disks are eccentric, we show they are susceptible to a new dynamical instability. Gravitational forces between…
Galaxies with polar structures -- of which polar-ring galaxies (PRGs) are a prominent subclass -- contain components that are kinematically decoupled and highly inclined relative to the host galaxy's major axis. Modern deep optical surveys…
AIMS. To check whether the polar angle distribution of QSOs around nearby spiral galaxies is isotropic or not. METHODS. A statistical analysis of the polar angle distribution of large samples of QSOs from the SDSS survey and Monte Carlo…
Based on a new sample of 355 quasars with significant optical polarization and using complementary statistical methods, we confirm that quasar polarization vectors are not randomly oriented over the sky with a probability often in excess of…
Context. The magnetic field in spiral galaxies is known to have a large-scale spiral structure along the galactic disk and is observed as X-shaped in the halo of some galaxies. While the disk field can be well explained by dynamo action,…
While the total interior mass of a galaxy is reasonably well determined by a good rotation curve, the relative contributions from disk, bulge and halo are only weakly constrained by one-dimensional data. Barred galaxies are intrinsically…
We present observations of pseudobulges in S0 and spiral galaxies using imaging data taken with the Spitzer Infra-Red Array Camera. We have used 2-d bulge-disk-bar decomposition to determine structural parameters of 185 S0 galaxies and 31…
We analyzed the distribution of spin parity in spiral galaxies using the HSC DR2 data. The spiral winding parity of disk galaxies, observed as S-spiral or Z-spiral projected onto the sky plane, provides robust information on the sign of the…
Dust is a ubiquitous component in our Galaxy. It accounts for only $1\%$ mass of the ISM but still is an essential part of the Galaxy. It affects our view of the Galaxy by obscuring the starlight at shorter wavelengths and re-emitting in…
The rotation curves of dark matter dominated dwarf galaxies are analysed. The observations show that dark matter halos represent a one-parameter family with self similar density profiles. The global halo parameters, like total mass and…
We report a significant detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies due to gravitational lensing by foreground galaxies. A mean image polarisation of $<p>=0.011\pm 0.006$ is measured for…
According to recent reports there is an excess correlation and an apparent regularity in the galaxy one-dimensional polar distribution with a characteristic scale of 128 $h^{-1}$ Mpc. This aparent spatial periodicity can be naturally…
We considered a vacuum polarization inside a galaxy in the eikonal approximation and found that two possible types of polarization exist. The first type is described by the equation of state $p=\rho/3$, similar to radiation. Using the…
Star counts, obtained from a 2 x 2 degree area centered on NGC 6822 have revealed an optical image of this galaxy composed of two components: in addition to the well-known HI disk with its young stellar component, there is a spheroidal…
The Sun is located inside an extremely low density and quite irregular volume of the interstellar medium, known as the Local Cavity (LC). It has been widely believed that some kind of interaction could be occurring between the LC and Loop…