English
Related papers

Related papers: Microlensing towards LMC and M31

200 papers

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

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

The Andromeda Galaxy (M31) is an important test case for a number of microlensing surveys looking for massive compact halo objects (Machos). A long-standing theoretical prediction is that the high inclination of the M31 disk should induce…

Astrophysics · Physics 2009-11-10 E. Kerins

We report the discovery of a microlensing candidate projected 2'54" from the center of M32, on the side closest to M31. The blue color (R-I= 0.00 +/- 0.14) of the source argues strongly that it lies in the disk of M31, while the proximity…

Results are presented from the MACHO collaboration gravitational microlensing search. The experiment and the nearly 50 microlensing events that have been detected are described. Limits on the baryonic content of the halo are given, as are…

We consider the feasibility of directly observing gravitational microlensing in extra-galactic sources, whose stars are not generally resolved. This precludes use of the simple optical depth to microlensing formulation, which is applicable…

Astrophysics · Physics 2009-10-22 Wesley N. Colley

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

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…

The MACHO project carries out regular photometric monitoring of millions of stars in the Magellanic Clouds and Galactic Bulge, to search for very rare gravitational microlensing events due to compact objects in the galactic halo and disk. A…

Zhao has proposed that the microlensing events observed toward the Large Magellanic Cloud (LMC) could be due to faint stars in a dwarf galaxy or tidal debris lying along the line of sight to the LMC. Zaritsky & Lin claim to have detected…

Astrophysics · Physics 2007-05-23 Andrew Gould

Observations of caustic-crossing galaxies at redshift $0.7<z<1$ show a wealth of transient events. Most of them are believed to be microlensing events of highly magnified stars. Earlier work predicted such events should be common near the…

We propose and evaluate the feasibility of a new strategy to search for planets via microlensing. This new strategy is designed to detect planets in "wide" orbits, i.e., with orbital separation, $a$ greater than $\sim 1.5 R_E$. Planets in…

Astrophysics · Physics 2009-10-30 Rosanne Di Stefano , Richard A. Scalzo

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…

An expression is provided for the self-lensing optical depth of the thin LMC disk surrounded by a shroud of stars at larger scale heights. The formula is written in terms of the vertical velocity dispersion of the thin disk population. If…

Astrophysics · Physics 2009-10-31 N. W. Evans , E. J. Kerins

We analyze the first-year MACHO collaboration observations of microlensing towards the Galactic center using a new direct likelihood technique that is sensitive to the distribution of the events on the sky. We consider the full set of 41…

Astrophysics · Physics 2007-05-23 Geza Gyuk

The Andromeda Galaxy Stellar Robotic Microlensing Project (The Angstrom Project) aims to use stellar microlensing events to trace the structure and composition of the inner regions of the Andromeda Galaxy (M31). We present microlensing rate…

Astrophysics · Physics 2009-11-10 E. Kerins , M. J. Darnley , J. Duke , A. Gould , C. Han , Y. -B. Jeon , A. Newsam , B. -G. Park

By means of extensive galactic modeling we study the implications of the more than eighty microlensing events that have now been observed for the composition of the dark halo of the Galaxy, as well as for other properties of the Galaxy. We…

Astrophysics · Physics 2008-12-18 Evalyn I. Gates , Geza Gyuk , Michael S. Turner

Although a decade of microlensing searches towards the Large Magellanic Cloud (LMC) has detected 13-25 possible microlensing events, the nature and the location of the lenses, being either halo machos or LMC stars, remains a subject of…

Astrophysics · Physics 2009-11-07 HongSheng Zhao , Rodrigo Ibata , Geraint Lewis , Mike Irwin

We use detailed numerical simulations and theoretical estimates to show that, if confirmed, the unusually brief microlensing events observed by Sahu et al. (2001) in the field of the globular cluster M22 might be explained as a result of…

Astrophysics · Physics 2009-11-07 R. de la Fuente Marcos , C. de la Fuente Marcos

In this fourth 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 Small Magellanic…

‹ Prev 1 3 4 5 6 7 10 Next ›