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Related papers: Galactic Bulge Pixel Lensing Events

200 papers

Modern surveys of gravitational microlensing events have progressed to detecting thousands per year. Surveys are capable of probing Galactic structure, stellar evolution, lens populations, black hole physics, and the nature of dark matter.…

We present preliminary results of the analysis of 5 years of MACHO data on the Galactic bulge microlensing events with clump giants as sources. This class of events allows one to obtain robust conclusions because relatively bright clump…

Four microlensing collaborations are presently searching for compact matter in the Galaxy and all have detected possible candidates. Using the detection efficiencies recently published by the MACHO and OGLE collaborations, we present…

Astrophysics · Physics 2015-06-24 Eamonn J. Kerins

To improve photometric precision by removing blending effect, a newly developed technique of difference image analysis (DIA) is adopted by several gravitational microlensing experiment groups. However, the principal problem of the DIA…

Astrophysics · Physics 2009-10-31 Cheongho Han

In this paper, we investigate the applicability of the astrometric method to the determination of the lens parameters for gravitational microlensing events toward both the LMC and the Galactic bulge. For this analysis, we investigate the…

Astrophysics · Physics 2009-10-30 Cheongho Han , Kyongae Chang

We determine the microlensing event rate distribution, $\Gamma(t_{E})$, that is properly normalized by the first year MACHO group observations (Alcock et al. 1997). By comparing the determined $\Gamma(t_{E})$ with various MF models of lens…

Astrophysics · Physics 2007-05-23 Cheongho Han , Seunghun Lee

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

It has been shown that a flux--weighted full width at half maximum timescale of a microlensing event can be used in an unbiased estimator of the optical depth. For the first time, this allows a physical parameter to be easily estimated from…

Astrophysics · Physics 2009-10-31 Edward A. Baltz , Joseph Silk

A comprehensive new approach is presented for deriving probability densities of physical properties characterizing lens or source that constitute an observed galactic microlensing event. While previously encountered problems are overcome,…

Astrophysics · Physics 2009-11-11 M. Dominik

The parallax effect in ground-based microlensing (ML) observations consists of a distortion to the standard ML light curve arising from the Earth's orbital motion. In most cases, the resolution in current ML surveys is not accurate enough…

Astrophysics · Physics 2009-10-28 Ari Buchalter , Marc Kamionkowski

Perhaps as many as 30 parallax microlensing events are known, thanks to the efforts of the MACHO, OGLE, EROS and MOA experiments monitoring the bulge. Using Galactic models, we construct mock catalogues of microlensing light curves towards…

Astrophysics · Physics 2009-11-11 M. C. Smith , V. Belokurov , N. W. Evans , S. Mao , J. H. An

Tidal disruption events (TDEs) are multi-messenger transients in which a star is tidally destroyed by a supermassive black hole at the center of galaxies. The Rubin Observatory Legacy Survey of Space and Time (LSST) is anticipated to…

High Energy Astrophysical Phenomena · Physics 2024-10-30 K. Szekerczes , T. Ryu , S. H. Suyu , S. Huber , M. Oguri , L. Dai

We present and study the largest and the most comprehensive catalog of microlensing events ever constructed. The sample of standard microlensing events comprises 3718 unique events from years 2001--2009, with 1409 not detected before in…

As the number of detected gravitational wave sources increase with increasing sensitivity of the gravitational wave observatories, observing strongly lensed pair of events will become a real possibility. Lensed GW events will have very…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-29 Anupreeta More , Surhud More

We present the lightcurves of 21 gravitational microlensing events from the first six years of the MACHO Project gravitational microlensing survey which are likely examples of lensing by binary systems. These events were manually selected…

Astrophysics · Physics 2012-08-27 MACHO , GMAN collaborations , : , C. Alcock et al

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 outline a method by which the angular radii of giant and main sequence stars in the Galactic bulge can be measured to a few percent accuracy. The method combines ground-based photometry of caustic-crossing bulge microlensing events, with…

Astrophysics · Physics 2009-11-07 B. Scott Gaudi , David S. Graff , Cheongho Han

Upcoming LSST survey gives an unprecedented opportunity for studying populations of intrinsically faint objects using microlensing technique. Large field of view and aperture allow effective time-series observations of many stars in…

Instrumentation and Methods for Astrophysics · Physics 2019-02-13 Sedighe Sajadian , Radoslaw Poleski

Ongoing microlensing observations by OGLE and MOA regularly identify and conduct high-cadence sampling of lensing events with Einstein diameter crossing time, tau_E, of 16 or fewer days. Events with estimated values of tau_E of one to two…

Earth and Planetary Astrophysics · Physics 2015-05-14 Rosanne Di Stefano

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…

Astrophysics · Physics 2015-05-13 E. Kerins , A. C. Robin , D. J. Marshall