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Related papers: Generalized Microlensing Effective Timescale

200 papers

We use the timescale distribution of ~3000 microlensing events measured by the OGLE-III survey, together with accurate new made-to-measure dynamical models of the Galactic bulge/bar region, to measure the IMF in the inner Milky Way. The…

Astrophysics of Galaxies · Physics 2017-07-26 Christopher Wegg , Ortwin Gerhard , Matthieu Portail

Microlensing has a unique advantage for detecting dark objects in the Milky Way, such as free-floating planets, neutron stars, and stellar-mass black holes. Most microlensing surveys focus on the Galactic bulge, where higher stellar density…

Astrophysics of Galaxies · Physics 2024-11-11 Ruocheng Zhai , Antonio C. Rodriguez , Shude Mao , Casey Y. Lam , Eric C. Bellm , Josiah Purdum , Frank J. Masci , Avery Wold

We reexamine the usefulness of fitting blended lightcurve models to microlensing photometric data. We find agreement with previous workers (e.g. Wozniak & Paczynski) that this is a difficult proposition because of the degeneracy of blend…

Astrophysics · Physics 2009-11-13 Christian L. Thomas , Kim Griest

We investigate microlensing in the case where the lens is considered as an extended object. We use a multipolar expansion of the lens potential and show that the time-varying nature of the quadrupole contribution allows to separate it from…

Astrophysics · Physics 2008-11-26 Florian Dubath , Maria Alice Gasparini , Ruth Durrer

Planet detection through microlensing is usually limited by a well-known degeneracy in the Einstein timescale $t_E$, which prevents mass and distance of the lens to be univocally determined. It has been shown that a satellite in…

Earth and Planetary Astrophysics · Physics 2015-12-23 F. Mogavero , J. P. Beaulieu

We show that one can measure the effects of microlens parallax for binary microlensing events with three well-measured peaks -- two caustic crossings plus a cusp approach, and hence derive the projected Einstein radius. Since the angular…

Astrophysics · Physics 2007-05-23 Jin H. An , Andrew Gould

Astrometric microlensing will offer in the next future a new channel for investigating the nature of both lenses and sources involved in a gravitational microlensing event. The effect, corresponding to the shift of the position of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 A. A. Nucita , F. De Paolis , G. Ingrosso , M. Giordano , L. Manni

We estimate the rate of near-field microlensing events expected from all-sky surveys and investigate the properties of these events. Under the assumption that all lenses are composed of stars, our estimation of the event rate ranges from…

Astrophysics · Physics 2009-11-13 Cheongho Han

Gravitational microlensing is a robust tool to detect and directly measure the abundance and mass of any kind of compact objects, either in our galaxy or in the extragalatic domain. On basis to generic, broadly applicable arguments, it is…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 E. Mediavilla , J. Jiménez-Vicente

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

Optimisation of heat engines at the micro-scale has applications in biological and artificial nano-technology, and stimulates theoretical research in non-equilibrium statistical physics. Here we consider non-interacting overdamped particles…

Soft Condensed Matter · Physics 2021-06-02 Giulia Gronchi , Andrea Puglisi

We compute a microlensing map for the Galactic bar. The predicted event rate and event duration distribution are consistent with the $55$ events recently reported by the MACHO and OGLE collaborations. Most of the events are due to lensing…

Astrophysics · Physics 2015-06-24 HongSheng Zhao , R. M. Rich , D. N. Spergel

Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty…

Astrophysics · Physics 2009-11-13 Martin C. Smith , Przemyslaw Wozniak , Shude Mao , Takahiro Sumi

Most transit microlensing events due to very low-mass lens objects suffer from extreme finite-source effects. While modeling their light curves, there is a known continuous degeneracy between their relevant lensing parameters, i.e., the…

Instrumentation and Methods for Astrophysics · Physics 2023-04-20 Sedighe Sajadian

The dependence of microlensing time scale frequency distributions and optical depth toward the galactic center on galactic model parameters is explored in detail for a distribution of stars consisting of the Zhao (1996) bar and nucleus and…

Astrophysics · Physics 2009-10-30 S. J. Peale

We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…

Astrophysics · Physics 2009-11-07 Eric Agol

We estimate the detection efficiency of binary gravitational lensing events through the channel of high-magnification events. From this estimation, we find that binaries in the separations ranges of 0.1 < s < 10, 0.2 < s < 5, and 0.3 < s <…

Solar and Stellar Astrophysics · Physics 2014-11-20 Cheongho Han , Kyu-Ha Hwang

Microlensing is a powerful technique to study the Galactic population of "dark" objects such as exoplanets both bound and unbound, brown dwarfs, low-luminosity stars, old white dwarfs, neutron stars, and almost the only way to study…

Microlensing searches toward the inner galaxy $(|l|,|b|\leq 22.\hskip-2pt'5)$ have several major advantages. First, the event rate is strongly dominated by bulge-bulge lensing events where both the source and lens lie in the bulge. Second,…

Astrophysics · Physics 2009-10-22 Andrew Gould