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Related papers: Polarisation as a Tool for Gravitational Microlens…

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The EROS and MACHO collaborations have reported observations of light curves of stars in the Large Magellanic Cloud that are compatible with gravitational microlensing by intervening massive objects, presumably Brown-Dwarf stars. The OGLE…

Astrophysics · Physics 2015-06-24 A. de Rujula , G. Giudice , S. Mollerach , E. Roulet

We present preliminary results of the analysis of 5 years of MACHO data on the Galactic bulge microlensing events with clump giants as sources. In particular, we discuss: 1) the selection of `giant' events, 2) distribution of impact…

EROS (Exp\'erience de Recherche d'Objets Sombres) has been monitoring the luminosity of 4 million stars in the Large Magellanic Cloud in order to search for gravitational microlensing by unseen objects in the galactic halo. We present here…

Astrophysics · Physics 2008-02-03 R. Ansari

The recently reported microlensing events of the LMC have caused much excitement, and have been interpreted as due to `dark objects' (MACHOs) in the halo of our Galaxy. It is shown here that the stars within the LMC play a dominant role as…

Astrophysics · Physics 2009-10-22 Kailash C. Sahu

If the Galaxy contains ~10^{11}M_sol in cold gas clouds of ~Jovian mass and \~AU size, these clouds will act as converging lenses for optical light, magnifying background stars at a detectable rate. The resulting light curves can resemble…

Astrophysics · Physics 2009-10-30 B. T. Draine

We provide a status report on our search for dark matter in our Galaxy in the form of massive compact halo objects (or Machos), using gravitational microlensing of background stars. This search uses a very large format CCD camera on the…

Ongoing microlensing surveys have already yielded more than five hundred microlensing events, most of which have been identified in real-time. In this review I present the basic theory and observational status of these surveys. I highlight…

Astrophysics · Physics 2007-05-23 Shude Mao

Recently Alard\markcite{alard1996} proposed to detect the shift of a star's image centroid, $\delta x$, as a method to identify the lensed source among blended stars. Goldberg & Wo\'zniak\markcite{goldberg1997} actually applied this method…

Astrophysics · Physics 2009-10-30 Cheongho Han , Youngjin Jeong

Microlensing surveys search for the transient brightening of a background star that is the signature of gravitational lensing by a foreground compact object. This technique is an elegant way to search for astrophysical candidates that might…

Astrophysics · Physics 2007-05-23 Christopher W. Stubbs

Measurements of the microlensing optical depth and event rate toward the Large Magellanic Cloud (LMC) can be used to probe the distribution and mass function of compact objects in the direction toward that galaxy - in the Milky Way disk,…

In this work, we present the analysis of the binary microlensing event OGLE-2018-BLG-0022 that is detected toward the Galactic bulge field. The dense and continuous coverage with the high-quality photometry data from ground-based…

We present microlensing calculations for a Galactic model based on Han & Gould (2003), which is empirically normalised by star counts. We find good agreement between this model and data recently published by the MACHO and OGLE…

Astrophysics · Physics 2009-11-13 Alexander Wood , Shude Mao

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Djuna Croon , David McKeen , Nirmal Raj

The measurement of the integrated optical polarization of weakly gravitationally lensed galaxies can provide considerable constraints on lens models. The method outlined depends on fact that the orientation of the direction of optical…

Astrophysics · Physics 2009-10-30 Edouard Audit , John F. L. Simmons

Microlensing surveys have proven to be tremendously fruitful in providing valuable data products for many fields of astrophysics, from eclipse lightcurves for substellar candidates to limb darkening in stellar atmospheres. We report on a…

Astrophysics · Physics 2010-04-08 R. Ignace , J. E. Bjorkman , C. Bunker

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 $\sim10^{5}$…

Astrophysics of Galaxies · Physics 2015-07-03 Shi Dai , Martin C. Smith , Mengxiang Lin , Youling Yue , George Hobbs , Renxin Xu

We investigate the possibility of identifying massive objects (lenses) in the Galactic Center region (GC) by means of pulsar timing. The well known intensity change due to microlensing is found to be less important. For typical stellar…

Astrophysics · Physics 2016-08-30 N. Wex , J. Gil , M. Sendyk

Estimating the number of microlensing events observed in different parts of the Galactic bulge is a crucial point in planning microlensing experiments. Reliable estimates are especially important if observing resources are scarce, as is the…

Astrophysics of Galaxies · Physics 2015-12-09 R. Poleski

Aims. We study the impact of the parallax on the search for very long timescale microlensing events towards the Magellanic Clouds due to dark massive compact objects within the past MACHO and EROS, the ongoing MOA and OGLE, and the future…

Astrophysics of Galaxies · Physics 2020-07-16 T. Blaineau , M. Moniez

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…

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