Related papers: 'Scraggy' dark halos around bulge-less spiral gala…
Rapid advance has been made recently in accurate distance measurements for nearby ($D < 11$ Mpc) galaxies based on the magnitude of the tip of red giant branch stars resolved with the Hubble Space Telescope. We use observational properties…
We present a list of 220 face-on, almost bulgeless galaxies assumed to be counterparts to the objects from the Reference Flat Galaxy Catalog (RFGC). We selected the Sc, Scd and Sd-type galaxies according to their apparent axial ratio…
We consider dark masses measured from kinematic tracers at discrete radii in galaxies for which baryonic contributions to overall potentials are either subtracted or negligible. Recent work indicates that rotation curves due to dark matter…
We used the Revised Flat Galaxy Catalog (RFGC) to select 817 ultra-flat (UF) edge-on disk galaxies with blue and red apparent axial ratios of $(a/b)_B > 10.0$ and $(a/b)_R > 8.5$. The sample covering the whole sky, except the Milky Way…
Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…
We use a hybrid approach that combines high-resolution simulations of the formation of a Milky Way-like halo with a semi-analytic model of galaxy formation to study the mass content of dwarf galaxies in the concordance $\Lambda$CDM…
We present a revised and expanded catalog of satellite galaxies of a set of isolated spiral galaxies similar in luminosity to the Milky Way. This sample of 115 satellites, 69 of which were discovered in our multifiber redshift survey, is…
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…
We model the mass distributions of 40 high surface brightness spiral galaxies inside their optical radii, deriving parameters of mass models by matching the predicted velocities to observed velocity maps. We use constant mass-to-light disk…
We study the neutral hydrogen properties of a sample of 20 bulgeless disk galaxies (Sd - Sdm Hubble types), an interesting class that can be used to constrain galaxy formation and evolution, especially the role of mergers versus internal…
Using the Sloan Digital Sky Survey (SDSS), we probe the halo mass distribution by studying the velocities of satellites orbiting isolated galaxies. In a subsample that covers 2500 sq. degrees on the sky, we detect about 3000 satellites with…
We compiled an all-sky catalog of 451 nearby galaxies, each having an individual distance estimate $D \la 10$ Mpc or the radial velocity $V_{LG} < 550$ km s$^{-1}$. The catalog contains data on basic optical and HI properties of the…
We present a deep (50 hours exposed) image of the nearby spiral galaxy M 63 (NGC 5055), taken with a 0.14-m aperture telescope. The galaxy halo exhibits the known very faint system of stellar streams extending across 110 kpc. We found 5…
Studies of galaxy surveys in the context of the cold dark matter paradigm have shown that the mass of the dark matter halo and the total stellar mass are coupled through a function that varies smoothly with mass. Their average ratio…
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…
We have updated the classification of late-type galaxies presented in the Catalog of Isolated Galaxies (KIG) using the advanced digital sky surveys. Our search for companions around 959 KIG galaxies revealed 141 neighbors associated with…
We present dynamically-determined rotation-curve mass decompositions of 30 spiral galaxies, which were carried out to test the maximum-disk hypothesis and to quantify properties of their dark-matter (DM) halos. We used measured vertical…
We show that a significant correlation (up to 5sigma) emerges between the bulge index, defined to be larger for larger bulge/disk ratio, in spiral galaxies with similar luminosities in the Galaxy Zoo 2 of SDSS and the number of tidal-dwarf…
We construct self-consistent light and mass distribution models for 4 distant spiral galaxies. The models include a bulge, a disk and an isothermal dark matter. We find the luminosity profiles to have much steeper cut-off than that of a…
The relationship between galaxies and dark matter can be characterized by the halo mass of the central galaxy and the fraction of galaxies that are satellites. Here we present observational constraints from the SDSS on these quantities as a…