Related papers: Observing molecular hydrogen clouds and dark massi…
In the cold dark matter scenario, dark matter halos are assembled hierarchically from smaller subunits. Some of these subunits are disrupted during the merging process, whereas others survive temporarily in the form of subhalos. A…
High-resolution N-body simulations of dark matter halos indicate that the Milky Way contains numerous subhalos. When a dark matter subhalo passes in front of a star, the light from that star will be deflected by gravitational lensing,…
Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy's scale dark matter halos with galaxy-galaxy lensing techniques:…
I discuss the prospects for detecting the dark matter via the proper motion of sub-solar mass dark matter halos in the vicinity of the solar neighbourhood. Microhalos that survive tidal disruption could exhibit proper motion of order few…
The MACHO Project is searching for galactic dark matter in the form of massive compact halo objects (Machos). Millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and Galactic bulge are photometrically…
Hot gas trapped in a dark matter halo will produce a decrement in the surface brightness of the microwave background, the Sunyaev-Zel'dovich (SZ) effect. While massive clusters produce the strongest central SZ decrements, we point out that…
Circumgalactic gas around massive galaxies generally has a volume-filling component -- an atmosphere -- with a temperature determined by the potential-well depth of the galaxy's halo. If the atmosphere is near hydrostatic equilibrium and is…
Numerous microlensing survey programs have constrained the possibility of dark matter existing in the form of compact objects within the Galactic halo. These constraints on the dark matter fraction were derived under the assumption of…
We use the framework of microlensing to show that observations of binary systems, such as those made by {\it Gaia}, combined with follow-up weak lensing measurements, can provide a means to probe halos of exotic matter, possibly clumped…
Disk-halo models of the Galaxy and LMC are constructed and used to analyse the microlensing data-set. Deflectors in the LMC bar, disk and halo provide an optical depth to microlensing of $\sim 2 \times 10^{-7}$. Deflectors in the Galactic…
If the Dark Matter consists of primordial black holes (PBHs), we show that gravitational lensing of stars being monitored by NASA's Kepler search for extra-solar planets can cause significant numbers of detectable microlensing events. A…
We make use of a high-resolution zoom-in hydrodynamical simulation to investigate the impact of filaments on galaxy formation in their residing dark matter haloes. A method based on the density field and the Hoshen-Kopelman algorithm is…
We present the first M31 candidate microlensing events from the Microlensing Exploration of the Galaxy and Andromeda (MEGA) survey. MEGA uses several telescopes to detect microlensing towards the nearby Andromeda galaxy, M31, in order to…
The emission from dark ages halos in the lines of transitions between lowest rotational levels of hydrogen and hydrogen deuteride molecules is analyzed. It is assumed molecules to be excited by CMB and collisions with hydrogen atoms. The…
Within 8 years, the current microlensing surveys of M31 will provide several hundred events affecting unresolved stars. They will thus allow a statistical study of the dark matter in M31's halo. The NGST will resolve these stars and…
Current theories of structure formation predict specific density profiles of galaxy dark matter haloes, and with weak gravitational lensing we can probe these profiles on several scales. On small scales, higher-order shape distortions known…
If the halo of the lensing galaxy 0957+561 is made of massive compact objects (MACHOs), they must affect the lightcurves of the quasar images Q0957+561 A and B differently. We search for this microlensing effect in the double quasar by…
In the CDM scenario, dark matter halos are assembled hierarchically from smaller subunits. A long-standing problem with this picture is that the number of sub-halos predicted by CDM simulations is orders of magnitudes higher than the known…
The defining characteristic of the cold dark matter (CDM) hypothesis is the presence of a very large number of low-mass haloes, too small to have made a visible galaxy. Other hypotheses for the nature of the dark matter, such as warm dark…
The MACHO Project monitors millions of stars in the Large Magellanic Cloud, the Small Magellanic Cloud and the bulge of the Milky Way searching for the gravitational microlensing signature of baryonic dark matter. This Project has yielded…