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The astrometric signal of microlensing events caused by free floating planets

  • Lindita Hamolli
  • Mimoza Hafizi
  • Francesco De Paolis
  • Achille A. Nucita
Original Article

Abstract

Astrometric observations of microlensing events can be used to obtain important information about lenses. During these events, the shift of the position of the multiple image centroid with respect to the source star location can be measured. This effect, which is expected to occur on scales from micro-arcseconds to milli-arcseconds, depends on the lens-source-observer system physical parameters. Here, we consider the astrometric and photometric observations by space and ground-based telescopes of microlensing events towards the Galactic bulge caused by free floating planets (FFPs). We show that the efficiency of astrometric signal on photometrically detected microlensing events tends to increase for higher FFP masses in our Galaxy. In addition, we estimate that during five years of the Gaia observations, about a dozen of microlensing events caused by FFPs are expected to be detectable.

Keywords

Free floating planets, gravitational microlensing Astrometry 

Notes

Acknowledgements

FDP and AN acknowledge the support by the INFN projects TAsP and Euclid, respectively.

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Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.Department of PhysicsUniversity of TiranaTiranaAlbania
  2. 2.Department of Mathematics and Physics “Ennio De Giorgi” and INFNUniversity of SalentoLecceItaly

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