Related papers: Are polar rings indeed polar?
We investigate the angular distribution of satellite galaxies in and around pairs of galaxy groups in SDSS and compare the results with the satellite distribution in pairs of dark matter halos by constructing mock catalogs that account for…
We present the first deep photometry of a good candidate for a forming polar ring galaxy at redshift z~0.05. This object, named FCSS J033710.0-354727, is a background galaxy in the VST deep field of the Fornax cluster. The deep exposures…
In this paper we present a statistical study of the environments of 49 galaxies in which there is gas- or stellar- counterrotation. The number of possible companions in the field (to apparent magnitude 22), their size and concentration were…
We study the three-dimensional and projected shapes of galaxy groups in the Sloan Digital Sky Survey Data Release 4, and examine the alignment between the orientation of the central galaxy and the spatial distribution of satellite galaxies.…
In the past years a wealth of observations allowed to unravel the structural properties of the Dark Matter Halos around spirals. First, their rotation curves follow an Universal profile (URC) that can be described in terms of an exponential…
The disks of spiral galaxies are generally elliptical rather than circular. The distribution of ellipticities can be fit with a log-normal distribution. For a sample of 12,764 galaxies from the Sloan Digital Sky Survey Data Release 1 (SDSS…
In the latest ten years, a big effort has given to study the morphology and kinematics of polar ring galaxies: many steps forward and new discoveries on the structure and formation mechanisms for such systems have been made during this time…
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…
In order to verify the existence of coherent orientations of quasars polarization vectors on very large scales, we have obtained new polarization measurements for a sample of quasars located in a given region of the three-dimensional…
We have measured the optical linear polarization of quasars belonging to Gpc-scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar polarization vectors are either parallel…
We present a brief summary of our current results on the stellar distribution and population gradients of the resolved stars in the surroundings of ~50 nearby disk galaxies, observed with space- (Hubble & Spitzer) and ground-based…
Optical polarimeters are typically calibrated using measurements of stars with known and stable polarization parameters. However, there is a lack of such stars available across the sky. Many of the currently available standards are not…
We present a statistical study of the environments of massive galaxies in four redshift bins between z=0.04 and z=1.6, using data from the Sloan Digital Sky Survey (SDSS) and the NEWFIRM Medium Band Survey (NMBS). We measure the projected…
The circular polarization of light that planets reflect is often neglected because it is very small compared to the linear polarization. It could, however, provide information on a planet's atmosphere and surface, and on the presence of…
We have investigated the Tully-Fisher relation for Polar Ring Galaxies (PRGs), based on near infrared, optical and HI data available for a sample of these peculiar objects. Many PRGs show larger HI line-widths than expected for the observed…
Circumbinary gas disks that are misaligned to the binary orbital plane evolve toward either a coplanar or a polar-aligned configuration with respect to the binary host. The preferred alignment depends on the dynamics of the disk: whether it…
Multiple observations made by several different telescopes have shown asymmetry between the number of spiral galaxies rotating in opposite directions in different parts of the sky. One of the immediate questions regarding the possible…
We analyze the orbits of stars and dark matter particles in the halo of a disk galaxy formed in a cosmological hydrodynamical simulation. The halo is oblate within the inner ~20 kpc and triaxial beyond this radius. About 43% of orbits are…
We present an analysis of new observations of a peculiar galaxy PGC 60020, obtained with the 6-m BTA telescope of the SAO RAS with a multimode SCORPIO instrument. The observational data includes direct images in the B, V, Rc photometric…
The 11 known satellite galaxies within 250 kpc of the Milky Way lie close to a great circle on the sky. We use high resolution N-body simulations of galactic dark matter halos to test if this remarkable property can be understood within the…