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Related papers: The Case for a Next Generation LMC Microlensing Su…

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If the massive compact halo object (MACHO) fraction of the Galactic dark halo is f ~ 20% as suggested by some microlensing experiments, then about 1.2% of lensing events toward the Galactic bulge are due to MACHOs. For the 40% of these that…

Astrophysics · Physics 2009-11-10 Andrew Gould

I present a new analysis of the MACHO Project 5.7 year Large Magellanic Cloud (LMC) microlensing data set that incorporates the effects of contamination of the microlensing event sample by variable stars. Photometric monitoring of MACHO LMC…

Astrophysics · Physics 2009-11-10 David P. Bennett

The microlensing of background stars by compact objects in globular clusters is analyzed. The main strength of the proposed search is the direct relationship between the lens mass and the time scale of the microlensing event. The main…

Astrophysics · Physics 2007-05-23 Bohdan Paczynski

The historical microlensing surveys MACHO, EROS, MOA and OGLE (hereafter summarized in the MEMO acronym) have searched for microlensing toward the LMC for a total duration of 27 years. We have studied the potential of joining all databases…

Instrumentation and Methods for Astrophysics · Physics 2018-09-10 Marc Moniez , Arash Mirhosseini

If the Dark Matter consists of primordial black holes (PBHs), we show that gravitational lensing of stars being monitored by NASA's Kepler search for extra-solar planets can cause significant numbers of detectable microlensing events. A…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Kim Griest , Matthew J. Lehner , Agnieszka M. Cieplak , Bhuvnesh Jain

We present an update of results from the search for microlensing towards the Large Magellanic Cloud (LMC) by EROS (Experience de Recherche d'Objets Sombres). We have now monitored 25 million stars over three years. Because of the small…

Astrophysics · Physics 2019-08-14 A. Milsztajn , T. Lasserre

If the dark halo matter is primarily composed of MACHOs toward the lower end of the possible detection range ($ < 10^{-3}$ $M_{\odot}$) a fraction of the lens detection events should involve the lens crossing directly in front of the disk…

Astrophysics · Physics 2009-10-22 Robert J. Nemiroff , W. A. D. Thulsi Wickramasinghe

Though stellar-mass black holes (BHs) are likely abundant in the Milky Way (N=10^8-10^9), only ~20 have been detected to date, all in accreting binary systems (Casares 2006). Gravitational microlensing is a proposed technique to search for…

Solar and Stellar Astrophysics · Physics 2021-05-26 Fatima N. Abdurrahman , Haynes F. Stephens , Jessica R. Lu

A particular open problem in cosmology is whether dark matter on small scales is clumpy, forming gravitationally-bound halos distributed within the Galaxy. The practical difficulties inherent in testing this hypothesis stem from the fact…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-13 Francesca von Braun-Bates

A simple interpretation of the more than dozen microlensing events seen in the direction of the LMC is a halo population of MACHOs which accounts for about half of the mass of the Galaxy. Such an interpretation is not without its problems,…

Astrophysics · Physics 2009-10-30 Evalyn I. Gates , Geza Gyuk , Gilbert P. Holder , Michael S. Turner

The primary goal of this paper is to provide the evidence that can either prove or falsify the hypothesis that dark matter in the Galactic halo can clump into stellar-mass compact objects. If such objects existed, they would act as lenses…

The detection of microlensing has opened the way for the development of new methods in galactic astronomy. This series of papers investigates what microlensing can teach us about the structure and shape of the dark halo. In this paper we…

Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy's scale dark matter halos with galaxy-galaxy lensing techniques:…

Astrophysics · Physics 2007-05-23 M. Limousin , J-P. Kneib , P. Natarajan

We describe a project of brown dwarf detection in the dark halo of a galaxy using the microlensing effect. We argue that monitoring pixels instead of stars could provide an enhancement in the number of detectable events. We estimate the…

Gravitational microlensing method is a powerful method to detect isolated black holes in the Milky Way. During a microlensing event brightness of the source increases and this feature is used by many photometric surveys to alert on…

Solar and Stellar Astrophysics · Physics 2024-02-06 I. Gezer , Ł. Wyrzykowski , P. Zieliński , G. Marton , K. Kruszyńska , K. A. Rybicki , N. Ihanec , M. Jabłońska , O. Ziółkowska

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

Within 8 years, the current microlensing surveys of M31 will provide several hundred events affecting unresolved stars. They will thus allow a statistical study of the dark matter in M31's halo. The NGST will resolve these stars and…

Astrophysics · Physics 2007-05-23 S. Bensammar , A. -L. Melchior

The recent binary microlensing event toward the Small Magellanic Cloud MACHO-98-SMC-1 was alerted by the MACHO collaboration and monitored by many microlensing experiments for its complete coverage of the second caustic crossing. The…

Astrophysics · Physics 2007-05-23 Sun Hong Rhie

We conduct gravitational microlensing experiments in a galaxy taken from a cosmological N-body simulation. Hypothetical observers measure the optical depth and event rate toward hypothetical LMCs and compare their results with model…

Astrophysics · Physics 2009-10-30 Lawrence M. Widrow , John Dubinski

Gravitational microlensing finds planets through their gravitational influence on the light coming from a more distant background star. The presence of the planet is then inferred from the tell-tale brightness variations of the background…

Earth and Planetary Astrophysics · Physics 2018-10-15 Yiannis Tsapras
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