A theoretical calculation of microlensing signatures caused by free-floating planets towards the Galactic bulge

Abstract

Free-floating planets are recently drawing a special interest of the scientific community. Gravitational microlensing is up to now the exclusive method for the investigation of free-floating planets, including their spatial distribution function and mass function. In this work, we examine the possibility that the future Euclid space-based observatory may allow to discover a substantial number of microlensing events caused by free-floating planets. Based on latest results about the free-floating planet mass function in the mass range $[10^{-5},10^{-2}]M_{\odot }$, we calculate the optical depth towards the Galactic bulge as well as the expected microlensing rate and find that Euclid may be able to detect hundreds to thousands of these events per month. Making use of a synthetic population, we also investigate the possibility of detecting parallax effect in simulated microlensing events due to free-floating planets and find a significant efficiency for the parallax detection that turns out to be around 30%.

arXiv commentPaper published in IJMPD 22, 1350072, 2013; 14 pages, 3 tables, 3 figures

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Cited by in corpus (5)

• Estimating Finite Source Effects in Microlensing Events due to Free-Floating Planets with the Euclid Survey
• Probability of simultaneous parallax detection for free-floating planet microlensing events near Galactic Centre
• The impact of the free-floating planet (FFP) mass function on the event rate for the accurate microlensing parallax determination: application to Euclid and Roman parallax observation
• The astrometric signal of microlensing events caused by free floating planets
• Gravitational microlensing constraints on primordial black holes by Euclid