Related papers: Globular clusters vs dark matter haloes in strong …
Deep images of 10 early-type galaxies in low-density environments have been obtained with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The global properties of the globular cluster (GC) systems of the galaxies have…
One of the frontiers for advancing what is known about dark matter lies in using strong gravitational lenses to characterize the population of the smallest dark matter halos. There is a large volume of information in strong gravitational…
The halo assembly bias, a phenomenon referring to dependencies of the large-scale bias of a dark matter halo other than its mass, is a fundamental property of the standard cosmological model. First discovered in 2005 from the Millennium Run…
We explore the halo structure of four gravitational lenses with well-observed, thin Einstein rings. We find that the gravitational potentials are well described by ellipsoidal density distributions in the sense that the best-fit…
A particular open problem in cosmology is whether dark matter on small scales is clumpy, forming gravitationally-bound halos distributed within the Galaxy. The practical difficulties inherent in testing this hypothesis stem from the fact…
According to the Cold Dark Matter (CDM) hierarchical clustering theory of galaxy and large scale structure formation, there should be numerous low mass dark matter haloes present in the Universe today. If these haloes contain sufficient…
Observations of strong gravitational lensing, stellar kinematics, and larger-scale tracers enable accurate measures of the distribution of dark matter (DM) and baryons in massive early-type galaxies (ETGs). While such techniques have been…
An increasing body of data reveals a one-to-one linear correlation between galaxy halo mass and the total mass in its globular cluster (GC) population, M_{GCS} ~ M_h^{1.03 \pm 0.03}, valid over 5 orders of magnitude. We explore the nature…
The core mass of galaxy clusters is both an important anchor of the radial mass distribution profile and probe of structure formation. With thousands of strong lensing galaxy clusters being discovered by current and upcoming surveys,…
Gravitational waves from binary black holes that are gravitationally lensed can be distorted by small microlenses along the line of sight. Microlenses with masses of a few tens of solar masses, and that are close to a critical curve in the…
Based on deep high resolution JWST images of AS1063, and after a careful masking of artifacts, extended features in the cluster, and background galaxies (including known lensed ones), we have identified tens of thousands of unresolved point…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
Stellar microlensing observations tightly constrain compact object dark matter in the mass range $(10^{-11} - 10^{3}) M_{\odot}$. Primordial Black Holes (PBHs) form clusters, and it has been argued that these microlensing constraints are…
The luminosity distribution of globular clusters shows a dramatic dependence on parent galaxy luminosity. Dwarf galaxies contain far more faint globulars than do luminous galaxies. This difference is significant at the 99.7% level. On the…
Globular cluster systems exhibit a bewildering variety of characteristics. No single scenario appears to be able to account for the wide range of specific globular cluster frequencies that are observed in galaxies of various types. The…
The dark matter content of globular clusters, highly compact gravity-bound stellar systems, is unknown. It is also generally unknow*able*, due to their mass-to-light ratios typically ranging between 1$-$3 in solar units, accommodating a…
Axions are a viable candidate for Cold Dark Matter (CDM) which should generically form minihalos of sub-planetary masses from white-noise isocurvature density fluctuations if the Peccei-Quinn phase transition occurs after inflation. Despite…
It is well known that Globular cluster systems are different among galaxies. Here we test to which degree these differences remain on the scale of galaxy clusters by comparing the globular clusters (GCs) in optical surveys of the Virgo…
We investigate the gravitational lensing properties of dark matter halos with Burkert profiles. We derive an analytic expression for the lens equation and use it to compute the magnification, impact parameter and image separations for…
Deep JWST images of AS1063 reveals tens of thousands of globular clusters in the galaxy cluster AS1063. When compared with the lensing model based on the same JWST data, the distribution of globular clusters traces closely the distribution…