Related papers: Towards a higher mass for NGC1052-DF2: an analysis…
NGC1052-DF2 and NGC1052-DF4 are ultra-diffuse galaxies (UDGs) that were found to have extremely low velocity dispersions, indicating that they have little or no dark matter. Both galaxies host anomalously luminous globular cluster (GC)…
We present new J=1-0 12-CO observations along the northern spiral arm of the grand-design spiral galaxy M100 (NGC 4321), and study the distribution of molecular hydrogen as derived from these observations, comparing the new data with a set…
We present a study of the dynamical properties of 125 compact stellar systems (CSSs) in the nearby giant elliptical galaxy NGC5128, using high-resolution spectra (R 26,000) obtained with VLT/FLAMES. Our results provide evidence for a new…
We construct a mass model for the spiral lens galaxy 2237+0305, at redshift z_l=0.04, based on gravitational-lensing constraints, HI rotation, and new stellar-kinematic information, based on data taken with the ESI spectrograph on the 10m…
An overall analysis of the structure and stellar content of M11 is presented, thanks to the wide-angle 2MASS spatial coverage. We derive photometric and structural parameters and discuss the spatial dependance of the luminosity and mass…
We use the distribution of maximum circular velocities, $V_{max}$, of satellites in the Milky Way (MW) to constrain the virial mass, $M_{200}$, of the Galactic halo under an assumed prior of a $\Lambda$CDM universe. This is done by…
We calculate the non-linear virialization density, $\Delta_c$, of halos under spherical collapse from peaks with an arbitrary initial and final density profile. This is in contrast to the standard calculation of $\Delta_c$ which assumes…
Low-mass dwarf galaxies ($M_{\rm vir} \lesssim 10^9\rm\ M_\odot$) are fundamental cosmological building blocks, yet the physical processes driving their structural diversity remain poorly understood. Recent numerical simulations have…
We present a theoretical analysis of galaxy-galaxy lensing in the context of halo models with CDM motivated dark matter profiles. The model enables us to separate between the central galactic and noncentral group/cluster contributions. We…
We study the radial distribution of subhalos and galaxies using high-resolution cosmological simulations of galaxy clusters formed in the concordance LCDM cosmology. In agreement with previous studies, we find that the radial distribution…
Studying the kinematics and mass modelling of galaxies from HI 21 cm data provides valuable insights into the properties of both the baryonic components and the dark matter halo in nearby galaxies. Despite many observational studies, mass…
We show that DM halos, in n--body simulations, have a boundary layer (BL), separating bound from unbound mass. Let T(r) and W(r) be the kinetic and potential energies in shells of halos. We find that, in almost all halos: (i) The virial…
Mass estimators are a key tool to infer the dark matter content in pressure-supported systems like dwarf spheroidal galaxies (dSphs). We construct an estimator for enclosed masses based on the virial theorem which is insensitive to…
We present a comprehensive analysis of the observed Stellar-to-Halo mass relationship (SHMR) spanning redshifts from 0.2 to 4.5. This was enabled through galaxy clustering and abundance measurements from two large (effective area ~ 1.61…
High mass galaxies, with halo masses $M_{200} \ge 10^{10} M_{\odot}$, reveal a remarkable near-linear relation between their globular cluster (GC) system mass and their host galaxy halo mass. Extending this relation to the mass range of…
When dark matter halos are accreted by massive host clusters, strong gravitational tidal forces begin stripping mass from the accreted subhalos. This stripping eventually removes all mass beyond a subhalo's tidal radius, but the unbound…
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 study relation between stellar mass and halo mass for high-mass halos using a sample of galaxy clusters with accurate measurements of stellar masses from optical and IR data and total masses from X-ray observations. We find that stellar…
We use 85 pairs of high resolution LCDM cosmological simulations from the NIHAO project to investigate why in dwarf galaxies neutral hydrogen (HI) linewidths measured at 50% of the peak flux W_50 /2 (from the hydrodynamical simulations)…
We study the stellar mass content of massive haloes in the redshift range 0.86<z<1.34, by measuring: (1) The stellar mass in the central galaxy versus total dynamical halo mass. (2) The total stellar mass (including satellites) versus total…