Related papers: Observable consequences of cold clouds as dark mat…
We use 350 mu angular diameter estimates from Planck to test the idea that some galaxies contain exceptionally cold (10-13 K) dust, since colder dust implies a lower surface brightness radiation field illuminating the dust, and hence a…
According to the cold dark matter scenario, a large number of dark subhalos should be located within the halo of each Milky-way sized galaxy. One promising possibility for detecting such subhalos is to try to observe their gravitational…
With future wide and deep cosmological sky surveys, a large number of gravitationally lensed, multiply imaged systems will be found. In addition to multiply imaged galaxies and quasars, sources will include transient events like supernovae…
We investigate the influence of the cooling epoch on the formation of galaxies in a cold dark matter dominated universe. Isolated haloes, with circular speeds typical of spiral galaxies, have been selected from a low resolution numerical…
Several observational lines of evidence imply that a fraction of the dark matter in the Galaxy may be comprised of small cold clouds of molecular hydrogen. Such objects are difficult to detect because of their small size and low…
We have monitored 8.6 million stars in the Large Magellanic Cloud for 1.1 years and have found 3 events consistent with gravitational microlensing. We place strong constraints on the Galactic halo content in the form of compact lensing…
Traditional evidence for large amount of dark matter is based on dynamical consideration for systems with $ t_{dyn} \gg t_{obs} $. Recent observational and theoretical developments in gravitational lensing offer a much more robust…
We study the formation of disks via the cooling flow of gas within galactic haloes using smoothed particle hydrodynamics simulations. These simulations resolve mass scales of a few thousand solar masses in the gas component for the first…
A generic prediction of particle dark matter theories is that a large population of dark matter substructures should reside inside the host haloes of galaxies. In gravitational imaging, strong gravitational lens observations are used to…
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…
The cold dark matter scenario of hierarchical large-scale structure formation predicts the existence of abundant subhalos around large galaxies. However, the number of observed dwarf galaxies is far from this theoretical prediction,…
It is proposed to search for scintillation of extragalactic sources through the last unknown baryonic structures. Appropriate observation of the scintillation process described here should allow one to detect column density stochastic…
Theoretical studies of structure formation find an inverse proportionality between the concentration of dark matter haloes and virial mass. This trend has been recently confirmed for virial masses Mvir > ~6e12 Msun by the observation of the…
The late infall of cold dark matter onto our galaxy produces discrete flows and caustics in its halo. The recently discovered ring of stars near galactocentric distance 20 kpc and a series of sharp rises in the Milky Way rotation curve are…
Major progresses have been made this last year towards a better knowledge of the invisible mass. Michel Spiro will talk in details about the micro-lensing experiments and their promising results; the ROSAT satellite has provided extended…
Gravitational lensing observations of massive X-ray clusters imply a steep characteristic density profile marked by a central concentration of dark matter. The observed mass fraction within a projected radius of 150 kpc is twice that found…
If the massive compact halo object (MACHO) fraction of the Galactic dark halo is f ~ 20% as suggested by some microlensing experiments, then about 1.2% of lensing events toward the Galactic bulge are due to MACHOs. For the 40% of these that…
We have searched for infrared dust emission from subsets of compact, Galactic neutral hydrogen clouds, with the purpose of looking for dust in high-velocity clouds, identifying low-velocity halo clouds, and investigating the cloud…
The French collaboration EROS and the American-Australian collaboration MACHO have reported the observation of altogether $\sim$ 10 microlensing events by monitoring during several years the brightness of millions of stars in the Large…
Models for the formation and growth of structure in a cold dark matter dominated universe predict that galaxy halos should contain significant substructure. Studies of the Milky Way, however, have yet to identify the expected few hundred…