2004/05/31 by L. Mancini, S. Calchi Novati, Ph. Jetzer +1 · 47 citations
Mathematics · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Asymmetry #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Gravitational microlensing #Halo #Large Magellanic Cloud #Limit (mathematics) #Line (geometry) #Mathematical analysis #Mathematics #Perspective (graphical) #Physics #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20034535
published in Astronomy and Astrophysics 427(1), 61-77 (EDP Sciences) · revised version (minor changes) Accepted for publication in A&A
arxiv created 2004/07/08 · openalex publication_date 2004/10/25 · arxiv updated 2014/10/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a new analysis of the location of the observed microlensing events in the direction of the Large Magellanic Cloud (LMC). This is carried out starting from a recently drawn coherent picture of the geometrical structure and dynamics of the LMC disk and by considering different configurations for the LMC bar. In this framework it clearly emerges that the spatial distribution of the events observed so far shows a near-far asymmetry. This turns out to be compatible with the optical depth calculated for the LMC halo objects. Our main conclusion, supported by a statistical analysis of the outcome of an evaluation of the microlensing rate, is that self-lensing cannot account for all the observed events. Finally we propose a general inequality to calculate quickly an upper limit to the optical depth along a line of view through the LMC center.