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Related papers: Microlensing search towards M31

200 papers

We have carried out a survey of the Andromeda galaxy for unresolved microlensing (pixel lensing). We present a subset of four short timescale, high signal-to-noise microlensing candidates found by imposing severe selection criteria: the…

We provide a set of microlensing event rate maps for M31, the Andromeda Galaxy. Rates for M31 microlensing were calculated on the basis of a four component model of the lens and source populations: disk and bulge sources lensed by bulge,…

Astrophysics · Physics 2009-11-07 Edward A. Baltz , Geza Gyuk , Arlin Crotts

POINT-AGAPE is an Anglo-French collaboration which is employing the Isaac Newton Telescope (INT) to conduct a pixel-lensing survey towards M31. In this paper we investigate what we can learn from pixel-lensing observables about the MACHO…

We report the discovery of a short-duration microlensing candidate in the northern field of the POINT-AGAPE pixel lensing survey towards M31. The full-width half-maximum timescale is very short, just 1.8 days. Almost certainly, the source…

We discuss the results of the MEGA microlensing campaign towards M31. Our analysis is based on an analytical evaluation of the microlensing rate, taking into account the observational efficiency as given by the MEGA collaboration. In…

We describe the results of a search for microlensing events affecting stars in the outer bulge and inner disk of M31, due both to masses in M31 and the Galaxy. These observations, from 1994 and 1995 on the Vatican Advanced Technology…

Astrophysics · Physics 2009-10-28 Arlin P. S. Crotts , Austin B. Tomaney

The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way, thus it is an important laboratory for studying massive dark objects in galactic halos (MACHOs) by gravitational microlensing. Such studies strongly complement the…

Astrophysics · Physics 2009-11-10 Edward A. Baltz

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

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

We describe the results and outline the methods used in a search for microlensing events affecting stars in the outer bulge and inner disk of M31, due both to masses in M31 and the Galaxy. These observations, from 1994 and 1995 on the…

Astrophysics · Physics 2007-05-23 Arlin P. S. Crotts

I demonstrate that one can detect pixel gravitational microlensing events at the rate $\sim 180\ {\rm events}\ {\rm yr}^{-1}$ and that some fraction of events ($\sim 15$) will be good enough to measure time scales at the $20\%$ level if the…

Astrophysics · Physics 2009-10-28 Cheongho Han

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2009-11-10 Philippe Jetzer , Sebastiano Calchi Novati

Microlensing is one of the most powerful tools for probing the nature of dark halo objects and the sources they lens. As our nearest massive galaxy, M31 provides a rich source population with many potential lenses in its halo crossing our…

Astrophysics of Galaxies · Physics 2025-09-16 Sophie L. Newman , Matthew J. Middleton , Adam McMaster

We analyse a series of pilot observations in order to study microlensing of (unresolved) stars in M31 with the 1.5m Loiano telescope, including observations on both identified variable source stars and reported microlensing events. We also…

Microlensing observations have now become a useful tool in searching for non--luminous astrophysical compact objects (brown dwarfs, faint stars, neutron stars, black holes and even planets). Originally conceived for establishing whether the…

Astrophysics · Physics 2016-08-30 E. Roulet , S. Mollerach

It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

The Pan-STARRS 1 (PS1) survey of M31 (PAndromeda) is designed to identify gravitational microlensing events, caused by bulge and disk stars (self-lensing) and by compact matter in the halos of M31 and the Milky Way (halo lensing, or lensing…

We apply the pixel method of analysis (sometimes called ``pixel lensing'') to a small subset of the EROS-1 microlensing observations of the bar of the Large Magellanic Cloud (LMC). The pixel method is designed to find microlensing events of…

Astrophysics · Physics 2007-05-23 A. -L. Melchior et al

I discuss current and future applications of pixel lensing: the microlensing of unresolved stars. Pixel lensing is the tool of choice for studying the Macho dark matter content of external galaxies like Andromeda (M31), and is at the heart…

Astrophysics · Physics 2007-05-23 Eamonn Kerins

We provide a set of microlensing optical depth maps for M31. Optical depths towards Andromeda were calculated on the basis of a four component model of the lens and source populations: disk and bulge sources lensed by bulge, M31 halo and…

Astrophysics · Physics 2007-05-23 Geza Gyuk , Arlin Crotts