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Related papers: The MACHO project: Microlensing Optical Depth towa…

200 papers

We present a systematic search for parallax microlensing events among a total of 512 microlensing candidates in the OGLE II database for the 1997-1999 seasons. We fit each microlensing candidate with both the standard microlensing model and…

Astrophysics · Physics 2009-11-07 M. C. Smith , S. Mao , P. R. Wozniak

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 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…

Astrophysics · Physics 2015-06-24 Yukitoshi Kan-ya , Ryoichi Nishi , Takashi Nakamura

By means of extensive galactic modeling we study the implications of the more than eighty microlensing events that have now been observed for the composition of the dark halo of the Galaxy, as well as for other properties of the Galaxy. We…

Astrophysics · Physics 2008-12-18 Evalyn I. Gates , Geza Gyuk , Michael S. Turner

We present the analysis of the light curves of 8.5 million stars observed during two seasons by EROS (Experience de Recherche d'Objets Sombres), in the galactic plane away from the bulge. Three stars have been found that exhibit luminosity…

Astrophysics · Physics 2008-11-26 F. Derue , C. Afonso , C. Alard , J-N. Albert

We propose to search for MACHOs by observing EAGLE (Extremely Amplified Gravitational LEnsing) events of a majority of dim stars. This search is independent of the usual one. For the detection limit of EAGLE (about 20 mag), about 100 f…

Astrophysics · Physics 2009-10-30 Takashi Nakamura , Ryoichi Nishi

Microlensing events are usually selected among single-peaked non-repeating light curves in order to avoid confusion with variable stars. However, a microlensing event may exhibit a second microlensing brightening episode when the source…

Astrophysics · Physics 2009-11-13 J. Skowron , L. Wyrzykowski , S. Mao , M. Jaroszynski

A high optical depth to gravitational microlensing towards the galactic bulge is consistent with current models of the galactic bar. The low optical depth towards the LMC can probably be accounted for by the ordinary stars in our galaxy and…

Astrophysics · Physics 2016-08-30 Bohdan Paczynski

We investigate whether Gaia can specify the binary fractions of massive stellar populations in the Galactic disk through astrometric microlensing. Furthermore, we study if some information about their mass distributions can be inferred via…

Solar and Stellar Astrophysics · Physics 2015-04-14 Sedighe Sajadian

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…

Astrophysics · Physics 2007-05-23 N. W. Evans , V. Belokurov

Extreme microlensing events, defined as events with maximum magnification $A_\max\gsim 200$ are a potentially powerful probe of the mass spectrum and spatial distribution of objects along lines of sight toward the Galactic bulge. About 75…

Astrophysics · Physics 2007-05-23 Andrew Gould

We have searched for long duration microlensing events originating from intermediate mass Black Holes (BH) in the halo of the Milky Way, using archival data from EROS-2 and MACHO photometric surveys towards the Large Magellanic Cloud. We…

We present a direct detection of the gravitational lens that caused the microlensing event MACHO-95-BLG-37. This is the first fully resolved microlensing system involving a source in the Galactic bulge, and the second such system in…

Astrophysics · Physics 2009-11-13 S. Kozlowski , P. R. Wozniak , S. Mao , A. Wood

We use the timescale distribution of ~3000 microlensing events measured by the OGLE-III survey, together with accurate new made-to-measure dynamical models of the Galactic bulge/bar region, to measure the IMF in the inner Milky Way. The…

Astrophysics of Galaxies · Physics 2017-07-26 Christopher Wegg , Ortwin Gerhard , Matthieu Portail

All current Bulge-Disk models for the inner Galaxy fall short of reproducing self-consistently the observed micro-lensing optical depth by a factor of two ($> 2\sigma$). We show that the least mass-consuming way to increase the optical…

Astrophysics · Physics 2016-08-30 M. Sevenster , A. Kalnajs

We investigate the possibility of determining whether microlensing objects towards the Large Magellanic Cloud (LMC) are in a Galactic thick disc, or are in a Galactic halo, by using parallax measurements with an Earth-radius scale baseline.…

Astrophysics · Physics 2009-11-07 T. Sumi , Y. Kan-ya

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…

Astrophysics · Physics 2009-11-11 Janne Holopainen , Chris Flynn , Alexander Knebe , Stuart P. Gill , Brad K. Gibson

The measurements of the possible gravitational microlensing events are analysed with a simple yet accurate disc--halo model of the Milky Way Galaxy. This comprises a luminous exponential disc embedded in a flattened dark matter halo with…

Astrophysics · Physics 2016-06-08 N. W. Evans , J. Jijina

OGLE III and MOA II are discovering 600-1000 Galactic Bulge microlens events each year. This stretches the resources available for intensive follow-up monitoring of the lightcurves in search of anomalies caused by planets near the lens…

Earth and Planetary Astrophysics · Physics 2015-05-13 Keith Horne , Colin Snodgrass , Yianni Tsapras