Related papers: Measuring the halo mass function in loose groups
We study the use of parallax microlensing to separate the effects of the mass function of dark massive halo objects (MHOs or `machos') on the one hand and their spatial distribution and kinematics on the other. This disentanglement is…
We combine data from a number of N-body simulations to predict the abundance of dark halos in Cold Dark Matter universes over more than 4 orders of magnitude in mass. A comparison of different simulations suggests that the dominant…
We present a new HI mass estimator which relates the HI-to-stellar mass ratio to four galaxy properties: stellar surface mass density, color index $u-r$, stellar mass and concentration index, with the scatter of individual galaxies around…
Using the group crossing time $t_{\rm c}$ as an age indicator for galaxy groups, we have investigated the correlation between $t_{\rm c}$ and the group spiral fraction, as well as between $t_{\rm c}$ and the neutral hydrogen gas fraction of…
Observations show that spiral galaxies in galaxy clusters tend to have on average less neutral hydrogen (HI) than galaxies of the same type and size in the field. There is accumulating evidence that such HI-deficient galaxies are also…
Observations show that galaxies in galaxy clusters are strongly influenced by their environment. There is growing evidence that some galaxies in groups show similar properties to galaxies in clusters, such as redder colours and gas…
We present an improved determination of the total mass distribution of three CLASH/HFF massive clusters, MACS J1206.2-0847 (z=0.44), MACS J0416.1-2403 (z=0.40), Abell S1063 (z=0.35). We specifically reconstruct the sub-halo mass component…
We study the dependence of galaxy clustering on atomic gas mass using a sample of $\sim$16,000 galaxies with redshift in the range of $0.0025<z<0.05$ and HI mass of $M_{\rm HI}>10^8M_{\odot}$, drawn from the 70% complete sample of the…
A robust prediction of $\Lambda{\rm CDM}$ cosmology is the halo circular velocity function (CVF), a dynamical cousin of the halo mass function. The correspondence between theoretical and observed CVFs is uncertain, however: cluster galaxies…
Using a large galaxy group catalogue constructed from the SDSS, we investigate the correlation between various galaxy properties and halo mass. We split the population of galaxies in early types, late types, and intermediate types, based on…
This exploration of solutions for the orbits of Local Group galaxies under the cosmological initial condition of growing peculiar velocities and fitted to measured distances, redshifts, and proper motions reveals a considerable variety of…
We measure the two-point redshift-space correlation function of loose groups of galaxies, xi_GG, for the combined CfA2 and SSRS2 surveys. Our combined group catalog constitutes the largest homogeneous sample available (885 groups). We…
We investigate the relationship between the halo mass, M_200, and concentration, c, for a sample of 26 group- and cluster-scale strong gravitational lenses. In contrast with previous results, we find that these systems are only ~ 0.1 dex…
Recently, we determined a lower bound for the Milky Way mass in a point mass approximation. This result was obtained for most general spherically symmetric phase-space distribution functions consistent with a measured radial velocity…
We investigate the impact of satellites, a potentially important contributor towards the cold gas assembly of a halo, on the cold gas budgets of 197 TNG50 simulated halos with masses of 10$^{10.85}$ $\le$ M$_{200c}$/M$_{\odot}$ $\le$…
We apply a spectral stacking technique to Westerbork Synthesis Radio Telescope observations to measure the neutral atomic hydrogen content (HI) of nearby galaxies in and around galaxy groups at $z < 0.11$. Our sample includes 577…
The Hubble Space Telescope (HST) has proven to be uniquely suited for the measurement of proper motions (PMs) of stars and galaxies in the nearby Universe. Here we summarize the main results and ongoing studies of the HSTPROMO…
We present a method to derive the dynamical mass of face-on galaxy disks using their neutral hydrogen (HI) velocity dispersion. We have applied the method to nearby, gas rich galaxies that have extended HI gas disks and have low…
Strong gravitational lensing can be used to directly measure the mass function of their satellites, thus testing one of the fundamental predictions of cold dark matter cosmological models. Given the importance of this test it is essential…
The local Hubble flow provides a valuable probe of the transition between cosmic expansion and nonlinear gravitational dynamics. On large scales, galaxies follow the linear Hubble law, but within group- and cluster-sized environments,…