Related papers: The Case for a Next Generation LMC Microlensing Su…
The aim of this paper is to investigate the claim that stars in the lensing galaxy of a gravitationally lensed quasar system can always account for the observed microlensing of the individual quasar images. A small sample of gravitationally…
I review proposals for explaining the current gravitational microlensing results from the EROS and MACHO surveys towards the Magellanic Clouds. Solutions involving massive compact halo objects (MACHOs), both baryonic and non-baryonic, as…
If the dark halo of our galaxy is made of compact objects as massive as M = 10^6 solar masses, their detection by means of ordinary microlensing searches would take a very long time as the characteristic time scale of such a lensing event,…
Microlensing observations towards M31 are a powerful tool for the study of the dark matter population in the form of MACHOs both in the Galaxy and the M31 halos, a still unresolved issue, as well as for the analysis of the characteristics…
In the context of this paper, microlenses present as oblate clusters of dark matter structures called massive astrophysical compact halo object(MACHO) in the galactic halo are considered. The NFW density profile [1] is derived from the…
The recent suggestion that the microlensing events observed towards the Large Magellanic Cloud are due to an intervening Sgr-like dwarf galaxy is examined. A search for foreground RR Lyrae in the MACHO photometry database yields 20 stars…
Microlensing results towards the LMC strongly depend on the properties of both the luminous and the dark matter distribution in the Galaxy. The two main sources of uncertainty come from the poor knowledge of the rotation curve at large…
In recent years various models for the Galactic distribution of massive compact halo objects (MACHOs) have been proposed for the interpretation of microlensing toward the Large Magellanic Cloud (LMC). A direct way to fit the best model is…
Short version: Zaritsky and Lin (1997, ZL97) have recently presented observations which can be interpreted as evidence for an intervening stellar population along the line-of-sight to the LMC, at a distance of ~34 kpc. They suggest that it…
The Milky Way's dark matter halo is expected to host numerous low-mass subhalos with no detectable associated stellar component. Such subhalos are invisible unless their dark matter annihilates to visible states such as photons. One of the…
Although a decade of microlensing searches towards the Large Magellanic Cloud (LMC) has detected 13-25 possible microlensing events, the nature and the location of the lenses, being either halo machos or LMC stars, remains a subject of…
If compact baryonic objects contribute significantly to the dark matter in our Galaxy, their mass function will present vital clues for galaxy formation theories and star formation processes in the early Universe. Here we discuss what one…
If the microlensing events now being detected toward the Large Magellanic Cloud (LMC) are due to lenses in the Milky Way halo, then the events should typically have asymmetries of order 1% due to parallax from the reflex motion of the…
In the third part of the series presenting the Optical Gravitational Lensing Experiment (OGLE) microlensing studies of the dark matter halo compact objects (MACHOs) we describe results of the OGLE-III monitoring of the Large Magellanic…
Microlensing studies of quasars can reveal dark matter lumps over a broad mass spectrum; we highlight the importance of monitoring quasars which are seen through the halos of low-redshift galaxies. For these configurations microlensing by…
Gravitational microlensing occurs when a foreground star happens to pass very close to our line of sight to a more distant background star. The foreground star acts as a lens, splitting the light from the source star into two images, which…
Some previous studies have suggested that massive and intermediate-mass primordial black holes (PBHs) could comprise a substantial fraction of dark matter in the Universe. Such black holes, if they existed in the Milky Way halo, would give…
I review recent results from gravitational microlensing surveys of the Large Magellanic Cloud. The combined microlensing optical depth of the MACHO and EROS-1 surveys is tau_LMC = 2.1{+1.3/-0.8}* 10^{-7} which is substantially larger than…
It has been proposed that the Galaxy might contain a population of cold clouds in numbers sufficient to account for a substantial fraction of the total mass of the Galaxy. These clouds would have masses of the order of 10^{-3} Solar mass…
Gravitational microlensing constraints on non-standard compact objects are conventionally derived assuming lenses trace the dark matter halo with velocities following a Maxwell-Boltzmann distribution centered around $10^{-3}c$. However, a…