相关论文: Microlensing by free-floating brown dwarfs

EROS has been monitoring few million stars in the Magellanic clouds, as well as toward the Galactic bulge and spiral arms since 1996, to search for microlensing events. In this paper, we present briefly the EROS setup and scientific program…

It has been shown by Paczy\'nski that gravitational microlensing is a useful method to detect brown dwarfs in the dark halo of our galaxy. At present several experiments are carried out to monitor several million stars in the Large…

At any instant, there are roughly 1000 ongoing microlensing events to sources brighter than 20th magnitude in the Milky Way Galaxy. Large-scale maps of the microlensing optical depth and the mean timescale are constructed for a number of…

We present an analysis of microlensing event OGLE-2016-BLG-0693, based on the survey-only microlensing observations by the OGLE and KMTNet groups. In order to analyze the light curve, we consider the effects of parallax, orbital motion, and…

Galactic bulge microlensing surveys provide a probe of Galactic structure. We present the first field-by-field comparison between microlensing observations and the Besan\c{c}on population synthesis Galactic model. Using an updated version…

One of the most important problems in astrophysics concerns the nature of the dark matter in galactic halos, whose presence is implied mainly by the observed flat rotation curves in spiral galaxies. In the framework of a baryonic scenario…

We analyze the first-year MACHO collaboration observations of microlensing towards the Galactic center using a new direct likelihood technique that is sensitive to the distribution of the events on the sky. We consider the full set of 41…

We present detailed maps of the microlensing optical depth and event density over an area of 195 sq. deg towards the Galactic bulge. The maps are computed from synthetic stellar catalogues generated from the Besancon Galaxy Model, which…

Gravitational microlensing is currently the only technique that helps study the Galactic distribution of planets as a function of distance from the Galactic center. The Galactic location of a lens system can be uniquely determined only when…

Many recent observational and theoretical studies suggest that globular clusters (GCs) host compact object populations large enough to play dominant roles in their overall dynamical evolution. Yet direct detection, particularly of black…

We estimate the rate of near-field microlensing events expected from all-sky surveys and investigate the properties of these events. Under the assumption that all lenses are composed of stars, our estimation of the event rate ranges from…

Results from gravitational microlensing suggested the existence of a large population of free-floating planetary mass objects. The main conclusion from this work was partly based on constraints from a direct imaging survey. This survey…

Microlensing and pixel-lensing surveys play a fundamental role in the searches for galactic dark matter and in the study of the galactic structure. Recent observations suggest the presence of a population of old white dwarfs with high…

We investigate properties of Galactic microlensing events in which a stellar object is lensed by a neutron star. For an all-sky photometric microlensing survey, we determine the number of lensing events caused by $\sim10^{5}$…

Following the suggestion of Gould and Depoy (1998) we investigate the feasibility of studying the brightest microlensing events towards the Galactic bulge using a small aperture (~10 cm) telescope. We used one of the HAT telescopes to…

Although a source star is fainter than the detection limit imposed by crowding, it is still possible to detect an event if the star is located in the seeing disk of a bright star is and gravitationally amplified: amplification bias. Using a…

In this paper, we report the discovery of a binary composed of a brown dwarf and a low-mass M dwarf from the observation of the microlensing event OGLE-2014-BLG-0257. Resolution of the very short-lasting caustic crossing combined with the…

We explore the usefulness of future gravitational microlensing surveys in the study of binary properties such as the binary fraction and the distributions of binary separation and mass ratio by using the binary sample detectable through a…

The EROS microlensing survey has monitored nearly 100 million stars for seven years, to search for halo brown dwarfs and compact objects in the Galactic disk. In this paper, we review the various EROS observation programs and the…

We present measurements of the microlensing optical depth and event rate toward the Galactic Bulge based on two years of the MOA-II survey. This sample contains ~1000 microlensing events, with an Einstein Radius crossing time of t_E < 200…