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Related papers: Microlensing towards different Galactic targets

200 papers

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

The MACHO Project is searching for galactic dark matter in the form of massive compact halo objects (Machos). Millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and Galactic bulge are photometrically…

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

The MACHO project is searching for dark matter in the form of massive compact halo objects (Machos), by monitoring the brightness of millions of stars in the Magellanic Clouds to search for gravitational microlensing events. Analysis of our…

After a decade of gravitational microlensing experiments, 13 to 17 events by MACHO (depending on quality) and two events by EROS have been detected. All of those have been observed in the direction of Large Magellanic Cloud. We use Evans…

Astrophysics · Physics 2009-11-07 Sohrab Rahvar

We present the results from the OGLE-II survey (1996-2000) towards the Large Magellanic Cloud (LMC), which has the aim of detecting the microlensing phenomena caused by dark matter compact objects in the Galactic Halo (Machos). We use high…

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 2017-08-23 Alexander F. Zakharov

Microlensing observations have now become a useful tool in searching for non--luminous astrophysical compact objects (brown dwarfs, faint stars, neutron stars, black holes and even planets). Originally conceived for establishing whether the…

Astrophysics · Physics 2016-08-30 E. Roulet , S. Mollerach

If compact baryonic objects contribute significantly to the dark matter in our Galaxy, their mass function will present vital clues for galaxy formation theories and star formation processes in the early Universe. Here we discuss what one…

Astrophysics · Physics 2008-11-26 E. J. Kerins , B. J. Carr

A large number of microlensing events have been observed in the direction of the Galactic bulge, with a measured optical depth in the range 2 - 3 x 10^{-6}. It has been shown that most of these events are due to bulge stars being lensed by…

Astrophysics · Physics 2009-10-30 Vibhat Nair , Jordi Miralda-Escude

Recently the French EROS collaboration and the American-Australian MACHO collaboration have reported the observation of altogether three possible microlensing events by monitoring over several years the brightness of millions of stars in…

Astrophysics · Physics 2009-10-22 Philippe Jetzer , Eduard Masso

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

Microlensing has established itself as a powerful new method for the detection of baryonic dark matter in the Galaxy. The theory of microlensing is sketched and its similarity with the optical effect of twinkling is explained. The bulk of…

Astrophysics · Physics 2007-05-23 Wyn Evans

We study the prospects for the current microlensing searches, which have recently discovered several candidates, to yield useful information about the flattening of the Galaxy dark matter halo. Models of HI warps and N-body simulations of…

Astrophysics · Physics 2009-10-22 Joshua A. Frieman , Román Scoccimarro

We detail how microlensing internal to M31 could be used to test whether a large fraction of the matter in spiral galaxy haloes is composed of dark objects with masses comparable to those of stars, and in the process show how the…

Astrophysics · Physics 2007-05-23 A. P. S. Crotts , R. Uglesich , G. Gyuk

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,…

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 French collaboration EROS and the American-Australian collaboration MACHO have reported the observation of altogether $\sim$ 10 microlensing events by monitoring during several years the brightness of millions of stars in the Large…

Astrophysics · Physics 2011-04-15 Philippe Jetzer

We present the microlensing optical depth towards the Galactic bulge based on the detection of 99 events found in our Difference Image Analysis (DIA) survey. This analysis encompasses three years of data, covering ~ 17 million stars in ~ 4…

Recent determination of the outer rotation curve of the Galaxy suggests that the total Galactic mass is likely to concentrate into a region of radius $\sim2R_0$. If this finding is correct, the previously estimated optical depth of…

Astrophysics · Physics 2016-08-30 Zong-Hong Zhu , Xiang-Ping Wu