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Related papers: Galactic Bulge Microlensing Events with Clump Gian…

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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

We find that significant incompleteness in stellar number counts results in a significant overestimate of the microlensing optical depth $\tau$ and event rate per star per year $\Gamma$ toward the Galactic bulge from the first two years of…

Astrophysics of Galaxies · Physics 2016-08-31 T. Sumi , M. T. Penny

The number and properties of observed gravitational microlensing events depend on the distribution and kinematics of stars and other compact objects along the line of sight. In particular, precise measurements of the microlensing optical…

The MACHO project has been monitoring about ten million stars in the Large Magellanic Cloud in the search for gravitational microlensing events caused by massive compact halo objects (Machos) in the halo of the Milky Way. In our standard…

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

It has been proposed that the MACHOs in our galaxy could be clumped in globular cluster--like associations or RAMBOs (robust associations of massive baryonic objects) (Moore \& Silk 1995). Here we investigate the effect such clustering has…

Astrophysics · Physics 2015-06-24 R Benton Metcalf , Joseph Silk

Searches for gravitational microlensing events are traditionally concentrated on the central regions of the Galactic bulge but many microlensing events are expected to occur in the Galactic plane, far from the Galactic Center. Owing to the…

By means of extensive galactic modeling we study the implications of the more than 100 microlensing events that have now been observed for the composition of the dark halo of the Galaxy. Based on the currently published data, including the…

Astrophysics · Physics 2007-05-23 Evalyn Gates , Geza Gyuk , Michael S. Turner

Foundations of standard theory of microlensing are described, namely we consider microlensing stars in Galactic bulge, the Magellanic Clouds or other nearby galaxies. We suppose that gravitational microlenses lie between an Earth observer…

Astrophysics · Physics 2007-05-23 A. F. Zakharov

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2007-05-23 Philippe Jetzer

The MACHO collaboration reports on the analysis of our first year LMC data, 9.5 million light curves with an average of 235 observations each. Automated selection procedures give 3 events consistent with microlensing. We evaluate our…

Microlensing campaigns have a long history of observations covering the Galactic bulge, where thousands of detections have been obtained, including many exoplanetary systems. The Euclid Galactic Bulge Survey represents a unique opportunity…

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

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2009-11-10 Philippe Jetzer , Sebastiano Calchi Novati

The microlensing surveys MACHO, EROS, MOA and OGLE (hereafter called MEMO) have searched for microlensing toward the Large Magellanic Cloud for a cumulated duration of 27 years. We study the potential of joining these databases to search…

Astrophysics of Galaxies · Physics 2018-10-19 Arash Mirhosseini , Marc Moniez

The analysis of the first three years of the OGLE data revealed 12 microlensing events of the Galactic bulge stars, with the characteristic time scales in the range $ 8.6 < t_0 < 80 $ days, where $ t_0 = R_E / V $. A complete sample of nine…

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…

The MACHO collaboration has recently analyzed 2.1 years of photometric data for about 8.5 million stars in the Large Magellanic Cloud (LMC). This analysis has revealed 8 candidate microlensing events and a total microlensing optical depth…

We completed the search for microlensing events in the zero latitude area of the Galactic bulge using the VVV Survey near-IR data obtained between 2010 and 2015. We have now a total sample of N = 630 events Using the near-IR Color-Magnitude…

Astrophysics of Galaxies · Physics 2018-09-26 María Gabriela Navarro , Dante Minniti , Rodrigo Contreras Ramos

The observations of microlensing events in the Large Magellanic Cloud suggest that a sizable fraction ($\sim$ 50%) of the galactic halo is in the form of MACHOs (Massive Astrophysical Compact Halo Objects) with an average mass $\sim 0.27…

Astrophysics · Physics 2007-05-23 F. De Paolis , Ph. Jetzer , G. Ingrosso , M. Roncadelli