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EROS has searched for microlensing toward four directions in the Galactic plane away from the Galactic center. The interpretation of the catalog optical depth is complicated by the spread of the source distance distribution. We compare the…

Astrophysics of Galaxies · Physics 2017-08-30 Marc Moniez , Sedighe Sajadian , Mansour Karami , Sohrab Rahvar , Reza Ansari

We present the analysis of the binary-lens microlensing event OGLE-2017-BLG-0537. The light curve of the event exhibits two strong caustic-crossing spikes among which the second caustic crossing was resolved by high-cadence surveys. It is…

Gravitational microlensing of planetary-mass objects (or "nanolensing", as it has been termed) can be used to probe the distribution of mass in a galaxy that is acting as a gravitational lens. Microlensing and nanolensing light curve…

Astrophysics of Galaxies · Physics 2015-06-03 H. Garsden , N. F. Bate , G. F. Lewis

In this paper, we investigate the intrinsic bias in detecting caustic crossings between Galactic halo and self-lensing events in the Magellanic Clouds. For this, we determine the region for optimal caustic-crossing detection in the…

Astrophysics · Physics 2009-10-31 Cheongho Han

With their excellent photometric precision and dramatic increase in monitoring frequency, future microlensing survey experiments are expected to be sensitive to very short time-scale, isolated events caused by free-floating and…

Astrophysics · Physics 2009-11-10 Cheongho Han , B. Scott Gaudi , Jin H. An , Andrew Gould

We present here an analysis of the light curves of 5.3 million stars in the Small Magellanic Cloud observed by EROS (Exp\'erience de Recherche d'Objets Sombres). One star exhibits a variation that is best interpreted as due to gravitational…

Astrophysics · Physics 2007-05-23 EROS collaboration , N. Palanque-Delabrouille et al

A significant fraction of non-baryonic or baryonic dark matter in galactic halos may consist of MASsive Compact Objects (MASCOs) with mass M=10^{1-4}M_{sun}. Possible candidates for such compact objects include primordial black holes or…

Astrophysics · Physics 2009-11-07 Kaiki Taro Inoue , Masashi Chiba

Extreme magnifications of distant objects by factors of several thousand have recently become a reality. Small very luminous compact objects, such as supernovae (SNe), giant stars at z=1-2, Pop III stars at z>7 and even gravitational waves…

Astrophysics of Galaxies · Physics 2019-05-22 Jose M. Diego

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

Current microlensing follow-up observations focus on high-magnification events because of the high efficiency of planet detection. However, central perturbations of high-magnification events caused by a planet can also be produced by a very…

Earth and Planetary Astrophysics · Physics 2015-06-04 Sun-Ju Chung , Kyu-Ha Hwang , Yoon-Hyun Ryu , Chung-Uk Lee

Macroscopic dark matter -- "macros"-- refers to a broad class of alternative candidates to particle dark matter with still unprobed regions of parameter space. These candidates would transfer energy primarily through elastic scattering with…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-17 Jagjit Singh Sidhu , Glenn D. Starkman

The monitoring of the gravitational lens Q2237+0305 carried out by the OGLE group during 1997--1999 is analyzed. The significant light amplifications in the C and A quasar components with maxima in mid- and late 1999, respectively, are…

Astrophysics · Physics 2009-11-06 V. N. Shalyapin

Five years of EROS data towards the Small Magellanic Cloud have been searched for gravitational microlensing events, using a new, more accurate method to assess the impact of stellar blending on the efficiency. Four long-duration candidates…

Astrophysics · Physics 2012-08-27 EROS Collaboration

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

We present photometric observations and analysis of the second microlensing event detected towards the Small Magellanic Cloud (SMC), MACHO Alert 98-SMC-1. This event was detected early enough to allow intensive observation of the…

The dark matter in Galactic halos, or some fraction of it, may be in the form of dark clusters which consist of small mass objects. Carr & Lacey (1987) have derived the permissible properties of such systems, and proposed the existence of…

Astrophysics · Physics 2009-10-22 Eyal Maoz

The four bright images of the gravitationally lensed quasar Q2237+0305 are being monitored from the ground (eg. OGLE collaboration, Apache Point Observatory) in the hope of observing a high magnification event (HME). Over the past three…

Astrophysics · Physics 2009-10-31 J. S. B. Wyithe , E. L. Turner , R. L. Webster

Gravitational microlensing by the stellar population of lensing galaxies provides an important opportunity to spatially resolve the accretion disk structure in strongly lensed quasars. Some of the objects (like Einstein's cross) are…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Nikolai I. Shakura , Pavel Abolmasov

We present novel findings concerning the parameter space of axion stars, extended object forming in dense dark matter environments through gravitational condensation. We emphasize their formation within the dense minihalos that potentially…

High Energy Physics - Phenomenology · Physics 2024-10-04 Ziwen Yin , Luca Visinelli

EROS has been monitoring few million stars in the Magellanic clouds, as well as toward the Galactic bulge and spiral arms since 1996, to search for microlensing events. In this paper, we present briefly the EROS setup and scientific program…

Astrophysics · Physics 2007-05-23 R. Ansari