Related papers: Microlensing results and the galactic models
Gravitational microlensing is known to be an impressive tool for searching dark, small, and compact objects that are missed by the usual astronomical observations. In this paper, by analysing multiple images acquired by DECam, we present…
Using neural networks, Belokurov, Evans & Le Du (2003, 2004) showed that 7 out of the 29 microlensing candidates towards the Large Magellanic Cloud (LMC) of the MACHO collaboration are consistent with blended microlensing and added Gaussian…
We describe a project of brown dwarf detection in the dark halo of a galaxy using the microlensing effect. We argue that monitoring pixels instead of stars could provide an enhancement in the number of detectable events. We estimate the…
We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M31), aimed to the detection of gravitational microlensing…
The longest microlensing events provide enough information to estimate the mass and distance of the lens. Among hundreds of millions of stars which were monitored for many years by the OGLE project we selected those with clear parallax…
Fifteen years or so ago, it was commonly argued; ``If we want to believe the observations rather than our prejudice, we should take as our best bet that dark haloes are baryonic.'' Such a viewpoint is not often heard today. This…
Using eight dark matter haloes extracted from fully-self consistent cosmological N-body simulations, we perform microlensing experiments. A hypothetical observer is placed at a distance of 8.5 kpc from the centre of the halo measuring…
Microlensing of distant stars in the Milky Way by the nearby high proper motion stars offers a direct way to precisely measure the masses of single lower main sequence stars and brown dwarfs.
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…
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…
We describe the results of a search for microlensing events affecting stars in the outer bulge and inner disk of M31, due both to masses in M31 and the Galaxy. These observations, from 1994 and 1995 on the Vatican Advanced Technology…
In microlensing of a Galactic star by a brown dwarf or other compact object, the amplified image really consists of two unresolved images with slightly different light-travel times. The difference (of order a microsecond) is GM/c^3 times a…
Four ongoing microlensing experiments have produced important new results but also big puzzles, the major one being that the expected classes of lenses cannot account for the observed distribution of time scales. I discuss future…
The primary goal of this paper is to provide the evidence that can either prove or falsify the hypothesis that dark matter in the Galactic halo can clump into stellar-mass compact objects. If such objects existed, they would act as lenses…
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…
It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6}<M/M_\odot<10^{-1}$.…
We present Hubble Space Telescope (HST) WFPC2 photometry of 13 microlensed source stars from the 5.7 year Large Magellanic Cloud (LMC) survey conducted by the MACHO Project. The microlensing source stars are identified by deriving accurate…
We consider a contribution of microlensing to the X-ray variability of high-redshifted QSOs. Such an effect could be caused by stellar mass objects (SMO) located in a bulge or/and in a halo of this quasar as well as at cosmological…
In the self--lensing framework, we estimate the modal values of the mass of the gravitational lenses found by the MACHO collaboration towards the Large Magellanic Cloud (LMC). Our results suggest that only the events located near the center…
Gravitational microlensing has been employed to identify massive halo objects by their amplification of distant sources; MACHO searches have studied event times $2 h \lesssim t_0 \lesssim 2 y$ corresponding masses in the range $10^{-6}…