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Related papers: Microlensing in globular clusters: the first confi…

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It has been suggested that a monitoring program employing the pixel lensing method to search for microlensing events towards galactic globular clusters may increase the statistics and discriminate among different halo models. Stimulated by…

Astrophysics · Physics 2009-11-07 V. F. Cardone , M. Cantiello

Gravitational microlensing is known to be an impressive tool for searching dark, small, and compact objects that are missed by the usual astronomical observations. In this paper, by analysing multiple images acquired by DECam, we present…

Astrophysics of Galaxies · Physics 2023-12-12 A. Franco , A. A. Nucita , F. De Paolis , F. Strafella

We search for microlensing events in fields along the Galactic minor axis, ranging from the Galactic center to -3.7<b< 3.9 deg., using the VVV survey near-IR photometry. The new search is made across VVV tiles b291, b305, b319, b347, b361…

Solar and Stellar Astrophysics · Physics 2020-02-05 Maria Gabriela Navarro , Dante Minniti , Joyce Pullen , Rodrigo Contreras Ramos

In the third part of the series presenting the Optical Gravitational Lensing Experiment (OGLE) microlensing studies of the dark matter halo compact objects (MACHOs) we describe results of the OGLE-III monitoring of the Large Magellanic…

We describe a new method to search for gravitational microlensing toward the Galactic bulge that employs a small camera rather than a conventional telescope and probes new regions of parameter space. The small aperture (~65 mm) permits…

Astrophysics · Physics 2009-10-30 Andrew Gould , D. L. DePoy

Despite consistent progress in numerical simulations, the observable properties of galaxy clusters are difficult to predict ab initio. It is therefore important to compare both theoretical and observational results to a direct measure of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Henk Hoekstra , Matthias Bartelmann , Haakon Dahle , Holger Israel , Marceau Limousin , Massimo Meneghetti

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

We investigate the possible existence of a high-redshift (z=1) cluster of galaxies associated with the QSO lens system MG2016+112. From an ultra-deep R- and less deep V- and I-band Keck images and a K-band mosaic from UKIRT, we detect ten…

Astrophysics · Physics 2009-10-31 D. Clowe , N. Trentham , J. Tonry

The effect of stars on the lensing properties of the supermassive black hole in the Galactic Center is similar to the effect of planets on microlensing by a star. We show that the dense stellar cluster around SgrA* increases by factors of a…

Astrophysics · Physics 2009-10-31 Tal Alexander , Abraham Loeb

Microlensing events can be used to directly measure the masses of single field stars to a precision of $\sim$1-10\%. The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of…

Solar and Stellar Astrophysics · Physics 2018-11-09 M. B. Nielsen , D. M. Bramich

We calculate the optical depth and the number of events due to gravitational microlensing towards the Galactic bulge, the spiral arm directions $\gamma$ Scutum, $\beta$ Scutum, $\gamma$ Normae, $\vartheta$ Muscae and some dwarf galaxies in…

Astrophysics · Physics 2007-05-23 Lukas Grenacher , Philippe Jetzer , Marcus Strässle , Francesco De Paolis

We present the first measurement of the mass function of galaxy clusters based directly on cluster masses derived from observations of weak gravitational lensing. To investigate the degree of sample incompleteness resulting from the X-ray…

Astrophysics · Physics 2009-02-06 H. Dahle

The study of extra-solar planetary systems has emerged as a new discipline of observational astronomy in the past few years with the discovery of a number of extra-solar planets. The properties of most of these extra-solar planets were not…

Microlensing planets occurring on faint source stars can escape detection due to their weak signals. Occasionally, detections of such planets are not reported due to the difficulty of extracting high-profile scientific issues on the…

We present the lightcurves of two microlensing events from the MACHO Project data that are likely to be due to lenses with masses similar to Jupiter's mass. Although the MACHO Project survey data are not sufficient to definitively establish…

We report the discovery of a cluster of galaxies via its weak gravitational lensing effect on background galaxies, the first spectroscopically confirmed cluster to be discovered through its gravitational effects rather than by its…

Astrophysics · Physics 2009-11-06 D. Wittman , J. A. Tyson , V. E. Margoniner , J. G. Cohen , I. P. Dell'Antonio

We investigate the chance of detecting proto-planetary or debris disks in stars that induce microlensing events (lenses). The modification of the light curves shapes due to occultation and extinction by the disks as well as the additional…

Earth and Planetary Astrophysics · Physics 2015-05-13 M. Hundertmark , F. V. Hessman , S. Dreizler

We present a survey of mass profiles and mass-to-light ratios of eight typical galaxy clusters at a common redshift (z ~ 0.2). We use weak gravitational lensing as a probe because it is unique in avoiding any assumptions about the dynamical…