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Related papers: Is There a Microlensing Puzzle?

200 papers

Microlensing is the tool of choice for the search and the analysis of compact halo objects ("MACHOs"), a still viable class of dark matter candidates at the galactic scale. Different analyses point towards an agreement in excluding dark…

Astrophysics of Galaxies · Physics 2015-06-03 S. Calchi Novati

In the framework of microlensing searches towards the Large Magellanic Cloud (LMC), we discuss the results presented by the OGLE collaboration for their OGLE-II campaign \citep{lukas09}. We evaluate the optical depth, the duration and the…

Astrophysics of Galaxies · Physics 2015-05-14 S. Calchi Novati , L. Mancini , G. Scarpetta , L. Wyrzykowski

Some previous studies have suggested that massive and intermediate-mass primordial black holes (PBHs) could comprise a substantial fraction of dark matter in the Universe. Such black holes, if they existed in the Milky Way halo, would give…

The simplest interpretation of the microlensing events towards the Large Magellanic Cloud detected by the MACHO and EROS collaborations is that about one third of the halo of our own Milky Way galaxy exists in the form of objects of around…

Astrophysics · Physics 2009-10-30 N. W. Evans , G. Gyuk , M. S. Turner , J. J. Binney

The EROS-2 project was designed to test the hypothesis that massive compact halo objects (the so-called ``machos'') could be a major component of the dark matter halo of the Milky Way galaxy. To this end, EROS-2 monitored over 6.7 years…

Microlensing results towards the LMC strongly depend on the properties of both the luminous and the dark matter distribution in the Galaxy. The two main sources of uncertainty come from the poor knowledge of the rotation curve at large…

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

The microlensing probability (optical depth $\tau$) toward the Galactic center carries information about the mass distribution of the Galactic bulge/bar, so can be used to constrain the very uncertain shape parameters of the bar. We find…

Astrophysics · Physics 2015-06-24 HongSheng Zhao , Shude Mao

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

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

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 off-centered "bar" of the Large Magellanic Cloud (LMC) is commonly assumed, for simplicity's sake, to lie in the same plane as the LMC disk. Relaxing this assumption to the extent allowed by the observations, we can drastically change…

Astrophysics · Physics 2009-10-31 H. S. Zhao , N. W. Evans

Aims. We study the impact of the parallax on the search for very long timescale microlensing events towards the Magellanic Clouds due to dark massive compact objects within the past MACHO and EROS, the ongoing MOA and OGLE, and the future…

Astrophysics of Galaxies · Physics 2020-07-16 T. Blaineau , M. Moniez

The suggestion by Zaritsky & Lin that a vertical extension of the red clump feature in color-magnitude diagrams of the Large Magellanic Cloud (LMC) is consistent with a significant population of foreground stars to the LMC that could…

Astrophysics · Physics 2009-10-31 Dennis Zaritsky , Stephen A. Shectman , Ian Thompson , Jason Harris , D. N. C. Lin

Microlensing surveys search for the transient brightening of a background star that is the signature of gravitational lensing by a foreground compact object. This technique is an elegant way to search for astrophysical candidates that might…

Astrophysics · Physics 2007-05-23 Christopher W. Stubbs

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

Source blending in microlensing experiments is known to modify the Einstein time of the observed events. In this paper, we have conducted Monte-Carlo calculations, using the analytical relationships derived by Han (1999) to quantify the…

Astrophysics · Physics 2009-11-11 Yann Alibert , Gilles Chabrier , Gerard Massacrier

It is shown that a significant amount of detectable gravitational microlensing events that could potentially be found by MAssively Parallel Photometry (MAPP) projects (such as the MACHO, EROS and OGLE collaborations) will occur for stars…

Astrophysics · Physics 2009-10-22 Robert J. Nemiroff

We estimate the fraction of mass that is composed of compact objects in gravitational lens galaxies. This study is based on microlensing measurements (obtained from the literature) of a sample of 29 quasar image pairs seen through 20 lens…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 E. Mediavilla , J. A. Munoz , E. Falco , V. Motta , E. Guerras , H. Canovas , C. Jean , A. Oscoz , A. M. Mosquera

Increasing evidences suggest that the Galactic halo is lumpy on kpc scales due to the accretion of at least a dozen small galaxies (LMC/SMC, Sgr, Fornax etc.). Faint stars in such lumpy structures can significant microlense a background…

Astrophysics · Physics 2009-10-30 HongSheng Zhao

We present a systematic comparison of three independent machine learning (ML)-based searches for strong gravitational lenses applied to the Dark Energy Survey (Jacobs et al. 2019a,b; Rojas et al. 2022; Gonzalez et al. 2025). Each search…