Related papers: The dark matter density problem in massive disk ga…
In its first part, this paper summarizes recent work on the mass and shape of the Galactic dark halo. The second part presents a review of the large-scale structure of the Milky Way, and of the evidence that the inner Galaxy is dominated by…
We study massive disk galaxies (total stellar mass$>=10^{11}$ $\mathrm{M_{\odot}}$) from IllustrisTNG50 simulation, and perform 2-D structural decomposition of the galaxies using their idealised, synthetic SDSS images for z=0. We find an…
I show that the predicted densities of the inner dark matter halos in LCDM models of structure formation appear to be higher than estimates from real galaxies and constraints from dynamical friction on bars. This inconsistency would not be…
Cosmological simulations indicate that cold dark matter (CDM) halos should be triaxial. Verifying observationally this theoretical prediction is, however, less than straightforward because the assembly of galaxies is expected to modify the…
I review what we currently do and do not know about the masses of disk galaxies and their dark matter halos. The prognosis for disks is good: the asymptotic rotation velocity provides a good indicator of total disk mass. The prognosis for…
Galaxies are composed of baryonic stars and gas embedded in dark matter halos. Here I briefly review two aspects of the connection between baryons and their halos. (1) The observed baryon content of galaxies falls short of the cosmic baryon…
We consider the possibility that the dark matter in the halos of galaxies may be in the form of clusters of \macho s within which are embedded cold, dense gas clouds. Microlensing experiments have found evidence that the Galactic halo…
The very careful Event Horizon Telescope estimate of the mass of the supermassive black hole at the center of the Giant CD galaxy M87, allied with recent high quality photometric and spectroscopic measurements, yields a proper dark/luminous…
We present results of numerical modeling made for the galactic stellar disk embedded in the spherical halo. The non-linear dynamics of bending instabilities developed in the disk is studied. The axisymmetrical bending mode is considered as…
The radial distribution of mass in a disk galaxy is strongly constrained by its rotation curve. The separate contributions from the individual stellar populations and dark matter (DM) are not easily disentangled, however, especially since…
The formation of disk galaxies is one of the most outstanding problems in modern astrophysics and cosmology. We review the progress made by numerical simulations carried out on large parallel supercomputers. Recent progress stems from a…
We consider the key problems related to measuring the mass of stellar disks and dark halos in galaxies and to explaining the observed properties of disks formed in massive dark halos.
A fine balance between dark and baryonic mass is observed in spiral galaxies. As the contribution of the baryons to the total rotation velocity increases, the contribution of the dark matter decreases by a compensating amount. This poses a…
N-body simulations and analytical calculations of the gravitational collapse in an expanding universe predict that halos should form with a diverging inner density profile, the cusp. There are some observational indications that the dark…
We use fully self-consistent N-body simulations of barred galaxies to show that dynamical friction from a dense dark matter halo dramatically slows the rotation rate of bars. Our result supports previous theoretical predictions for a bar…
The `maximum' disk hypothesis of galactic disks imbedded in dark matter halos is examined. First, decompositions of the rotation curves of NGC 2613, 3198, 6503, and 7184 are analyzed. For these galaxies the radial velocity dispersions of…
In this work we extend the study on the mass distribution of the spiral galaxy NGC 5278, performing 1D and 2D bulge-disk decomposition to determine which components constitute the baryonic mass in this galaxy. Our analysis does not detect…
We present stellar and ionized-gas velocity curves and velocity dispersion profiles for the Sa galaxies NGC 2179 and NGC 2775. Using their luminosity profiles and modeling both their stellar and gaseous kinematics, we have derived the mass…
The predicted central densities of dark matter halos in LCDM models exceed those observed in some galaxies. Weinberg & Katz argue that angular momentum transfer from a rotating bar in the baryonic disk can lower the halo density, but they…
The central part of a dark matter halo reacts to the presence and evolution of a bar. Not only does the halo absorb angular momentum from the disk, it can also be compressed and have its shape modified. We study these issues in a series of…