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We construct a multiparametric Tully–Fisher (TF) relation for a large sample of edge-on galaxies from the Revised Flat Galaxy Catalog using H  i data from the Extragalactic Distance Database and parameters from the edge-on disc galaxies catalogue. We incorporate a variety of additional parameters including structural parameters of edge-on galaxies in different bandpasses. Besides the rotation curve maximum, only the H  i -to-optical luminosity ratio and optical colours play a statistically significant role in the multiparametric TF relation. We are able to decrease the standard deviation of the multiparametric TF relation down to 0.32 mag, which is at the level of best modern samples of galaxies used for studies of the matter motion in the Universe via the TF relation. [ABSTRACT FROM AUTHOR]

We present a detailed photometric study of a sample of 22 edge-on galaxies with clearly visible X-shaped structures. We propose a novel method to derive geometrical parameters of these features, along with the parameters of their host galaxies based on the multi-component photometric decomposition of galactic images. To include the X-shaped structure into our photometric model, we use the IMFIT package, in which we implement a new component describing the X-shaped structure. This method is applied for a sample of galaxies with available Sloan Digital Sky Survey and Spitzer IRAC 3.6 μm observations. In order to explain our results, we perform realistic N-body simulations of aMilkyWay-type galaxy and compare the observed and the model X-shaped structures. Our main conclusions are as follows: (1) galaxies with strong X-shaped structures reside in approximately the same local environments as field galaxies; (2) the characteristic size of the X-shaped structures is about 2/3 of the bar size; (3) there is a correlation between the X-shaped structure size and its observed flatness: the larger structures are more flattened; (4) our N-body simulations qualitatively confirm the observational results and support the bar-driven scenario for the X-shaped structure formation. [ABSTRACT FROM AUTHOR]

We study the properties of galaxies with very thin discs (VTDs) using a sample of 85 objects whose stellar disc radial-to-vertical scale ratio determined from photometric decomposition, exceeds 9. We present evidences of similarities between the VTD galaxies and low surface brightness (LSB) disc galaxies, and conclude that both small and giant LSB galaxies may reveal themselves as VTD, edge-on galaxies. Our VTD galaxies are mostly bulgeless, and those with large radial scalelength tend to have redder colours. We performed spectral observations of 22 VTD galaxies with the Dual Imaging Spectrograph on the 3.5 m telescope at the Apache Point Observatory. The spectra with good resolution (R ~ 5000) allow us to determine the distance and the ionized gas rotation curve maximum for the galaxies. Our VTD galaxies have low dust content, in contrast to regular disc galaxies. Apparently, VTD galaxies reside in specific cosmological low-density environments and tend to have less connection with filaments. Comparing a toy model that assumes marginally low star formation in galactic discs with obtained gas kinematics data, we conclude that there is a threshold central surface density of about 88 Mʘ?pc-2, which we observe in the case of very thin, rotationally supported galactic discs. [ABSTRACT FROM AUTHOR]

Using N-body simulations (N ∼ 106–107), we examine how a non-axisymmetric dark halo affects the dynamical evolution of the structure in collisionless (stellar) discs. We demonstrate how the model parameters such as mass of the halo, initial conditions in the disc and the halo axis ratio affect morphology and kinematics of the stellar discs. We show that a non-axisymmetric halo can generate a large-scale spiral density pattern in the embedded stellar disc. The pattern is observed in the disc for many periods of its revolution, even if the disc is gravitationally overstable. The growth of the spiral arms is not accompanied by significant dynamical heating of the disc, irrelevant to its initial parameters. We also investigate transformation of the dark halo’s shape driven by the long-lived spiral pattern in the disc. We show that the analysis of the velocity field in the stellar disc and in the spiral pattern gives us a possibility to figure out the spatial orientation of the triaxial dark halo and to measure the triaxiality. [ABSTRACT FROM AUTHOR]

We present a catalog of true edge-on disk galaxies automatically selected from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS). A visual inspection of the g, r, and i images of about 15,000 galaxies allowed us to split the initial sample of edge-on galaxy candidates into 4768 (31.8% of the initial sample) genuine edge-on galaxies, 8350 (55.7%) non-edge-on galaxies, and 1865 (12.5%) edge-on galaxies not suitable for simple automatic analysis because these objects either show signs of interaction and warps, or nearby bright stars project on it. We added more candidate galaxies from RFGC, EFIGI, RC3, and Galaxy Zoo catalogs found in the SDSS footprints. Our final sample consists of 5747 genuine edge-on galaxies. We estimate the structural parameters of the stellar disks (the stellar disk thickness, radial scale length, and central surface brightness) in the galaxies by analyzing photometric profiles in each of the g, r, and i images. We also perform simplified three-dimensional modeling of the light distribution in the stellar disks of edge-on galaxies from our sample. Our large sample is intended to be used for studying scaling relations in the stellar disks and bulges and for estimating parameters of the thick disks in different types of galaxies via the image stacking. In this paper, we present the sample selection procedure and general description of the sample. [ABSTRACT FROM AUTHOR]

We carried out the multicolor surface photometry in BVR and griz filters parallel with stellar kinematic measurements from the long slit spectra for the low surface brightness galaxy Malin 2. The use of the multicolor surface photometry as well as the available HI rotation curve allowed us to construct the mass distribution model of the galaxy. Photometrical and dynamical mass estimates agree with the dark halo mass fraction of about 70% within four disc radial scalelengths (~ 70 kpc). We used our dynamical model to obtain radial profiles of the equilibrium disc volume density and gas pressure in the galaxy midplane based on the available HI and CO data. The observed molecular gas fraction appears to be much higher than in the high surface brightness galaxies for a similar gas pressure. [ABSTRACT FROM PUBLISHER]