Related papers: Gravitational Microlensing Results from MACHO
We perform an analytical study and a Monte Carlo (MC) analysis of the main features for microlensing events in pixel lensing observations towards M31. Our main aim is to investigate the lens nature and location of the 14 candidate events…
In a previous study it was proposed that the Galactic dark matter being detected by gravitational microlensing experiments such as MACHO may reside in a population of dim halo globular clusters comprising mostly or entirely low-mass stars…
We investigated the dependence of the optical depth $\tau$ of the microlensing events on model parameters of the Galactic halo. We only consider Galactic mass models in which the rotation curve inside the Sun is compatible with the…
The light curves of the two images of the double quasar Q0957+561 as obtained by Kundic et al. (1997) are almost identical, except for an overall time delay and scaling factor. This allows us to put limits on the amount of microlensing that…
We explore a novel search strategy for dark matter in the form of massive compact halo objects (MACHOs) such as primordial black holes or dense mini-halos in the mass range from $10^{-4}$ to 0.1 solar masses. These objects can…
We will review some results based on the EROS and the on going EROS-2 microlensing surveys to search for dark matter in the Galactic halo via microlensing effects on LMC/SMC stars. Microlensing surveys provide systematic observations for…
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…
The only microlensing events towards the Magellanic Clouds for which the location of the lens is strongly constrained are the two binary caustic crossing events. In at least one and possibly both cases, the lens lies at, or close to, the…
We present follow-up observations of a gravitational microlensing candidate found by the MACHO collaboration in the Galactic bulge. The photometric data cover a period near the maximum of the event and may be used to construct complete…
We present the final analysis of the observational campaign carried out by the PLAN (Pixel Lensing Andromeda) collaboration to detect a dark matter signal in form of MACHOs through the microlensing effect. The campaign consists of about 1…
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…
Zhao has proposed that the microlensing events observed toward the Large Magellanic Cloud (LMC) could be due to faint stars in a dwarf galaxy or tidal debris lying along the line of sight to the LMC. Zaritsky & Lin claim to have detected…
The discoveries of 17 microlensing event candidates have been reported over the last year by three teams conducting unprecedented mass photometric searches in the direction of the Galactic bulge and the Magellanic Clouds. These include 10…
Compact dark matter has been efficiently constrained in the M <~ 10 M_sun mass range by null searches for microlensing of stars in nearby galaxies. Here we propose to probe the mass range M >~ 10 M_sun by seeking echoes in gamma-ray-burst…
We present the analysis of the first two years of the OGLE search for gravitational lenses towards the Galactic bulge. We detected 9 microlensing events in an algorithmic search of $ \sim 10^8 $ measurements of $ \sim 10^6 $ stars. The…
We investigate the implications of a very thick (scale height 1.5 - 3.0 kpc) disk population of MACHOs. Such a population represents a reasonable alternative to standard halo configurations of a lensing population. We find that very thick…
Dark matter may be in the form of non-baryonic structures such as compact subhalos and boson stars. Structures weighing between asteroid and solar masses may be discovered via gravitational microlensing, an astronomical probe that has in…
We report the first discovery of a gravitational microlensing candidate towards a new population of source stars, the Small Magellanic Cloud (SMC). The candidate event's light curve shows no variation for 3 years before an upward excursion…
(Abridged Abstract) A favored interpretation of recent microlensing measurements towards the Large Magellanic Cloud implies that a large fraction (i.e. 10--50%) of the mass of the galactic halo is composed of white dwarfs. We compare model…
It is widely believed that dark matter halos are flattened, that is closer to oblate than prolate. The evidence cited is based largely on observations of galaxies which do not look anything like our own and on numerical simulations which…