On the detection of free-floating planets through microlensing towards the Magellanic Clouds

Abstract

In this work, we study detecting free-floating planets (FFPs) by microlensing observations towards the Magellanic Clouds (MCs). In comparison to similar events toward the Galactic bulge, an FFP in the Galactic halo produces on average longer microlensing events with smaller projected source radii toward these clouds. For these microlensing events, the relative lens-source velocities are on average smaller. The MC self-lensing events due to FFPs suffer from severe finite-source effects. We first simulate microlensing events due to FFPs towards MCs and assume a log-uniform step function for their mass. The efficiencies for capturing their lensing signatures (with signal-to-noise greater than $50$) are found to be $0.1$-$0.6\%$ and $3$-$6\%$ through ground-based optical surveys and space-based near-infrared surveys, respectively. We then promote these simulations and assume the \wfirst~telescope continuously observes each MC during one $72$-day season with the $15$min observing cadence. From simulated microlensing events with the resolvable source stars at the baseline due to FFPs with the masses $\sim 0.01$-$10^4{M}_{\oplus }$, \wfirst~discovers their lensing effects with the efficiencies $\sim 10$-$80\%$, respectively. By adopting $5\%$ as halos fraction from FFPs we estimate the expected number of events. The highest number of detectable FFPs which is $\sim 1700$-$2200$ per season per square degree happens for ones with masses $\sim 0.01M_{\oplus }$. Our simulations show that \wfirst~potentially extends the mass range of detectable FFPs in halos down to $5.9\times 10^{-7}{M}_{\oplus }$ with continuous observations during one observing season from the Large Magellanic Cloud.

arXiv comment15 pages, 5 tables, 8 figures

References in corpus (80)

• The Dartmouth Stellar Evolution Database
• The MACHO Project: Microlensing Results from 5.7 Years of LMC Observations
• Towards a Deterministic Model of Planetary Formation I: a Desert in the Mass and Semi Major Axis Distributions of Extra Solar Planets
• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Reddening and Extinction Toward the Galactic Bulge from OGLE-III: The Inner Milky Way's Rv ~ 2.5 Extinction Curve
• New Understanding of Large Magellanic Cloud Structure, Dynamics and Orbit from Carbon Star Kinematics
• The MACHO Project LMC Microlensing Results from the First Two Years and the Nature of the Galactic Dark Halo
• Extrasolar planet population synthesis I: Method, formation tracks and mass-distance distribution
• Microlensing constraints on primordial black holes with the Subaru/HSC Andromeda observation
• Unbound or Distant Planetary Mass Population Detected by Gravitational Microlensing
• Third-Epoch Magellanic Cloud Proper Motions I: HST/WFC3 data and Orbit Implications
• OGLE-2003-BLG-262: Finite-Source Effects from a Point-Mass Lens
• Magellanic Cloud Structure from Near-IR Surveys I: The Viewing Angles of the LMC
• No large population of unbound or wide-orbit Jupiter-mass planets
• Predictions of the WFIRST Microlensing Survey I: Bound Planet Detection Rates
• Stellar populations in the Milky Way bulge region : Towards solving the Galactic bulge and bar shapes using 2MASS data
• Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects
• The Extremely Red, Young L Dwarf PSO J318-22: A Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets
• Dynamical heating across the Milky Way disc using APOGEE and $Gaia$
• Toward a Deterministic Model of Planetary Formation VII: Eccentricity Distribution of Gas Giants
• Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. IV. Two bulge populations
• The OGLE View of Microlensing towards the Magellanic Clouds. IV. OGLE-III SMC Data and Final Conclusions on MACHOs
• New Optical Reddening Maps of the Large and Small Magellanic Clouds
• The Bar and Spiral Structure Legacy (BeSSeL) Survey: Mapping the Milky Way with VLBI Astrometry
• Magellanic Cloud Structure from Near-IR Surveys II: Star Count Maps and the Intrinsic Elongation of the LMC
• Experimental Limits on Primordial Black Hole Dark Matter from the First Two Years of Kepler Data
• Finite Source Sizes and the Information Content of MACHO-Type Lens Search Light Curves
• MOA-cam3: a wide-field mosaic CCD camera for a gravitational microlensing survey in New Zealand
• Microlensing with advanced contour integration algorithm: Green's theorem to third order, error control, optimal sampling and limb darkening
• The 3D structure of the Small Magellanic Cloud
• Planet-Planet Scattering Alone Cannot Explain the Free-Floating Planet Population
• Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey II: Free-Floating Planet Detection Rates
• A synthetic view on structure and evolution of the Milky Way
• Structure of the Large Magellanic Cloud from 2MASS
• Astrophysical Applications of Gravitational Microlensing
• Planetary and Other Short Binary Microlensing Events from the MOA Short Event Analysis
• VBBinaryLensing: a public package for microlensing light curve computation
• The mass-radius relationship from solar-type stars to terrestrial planets: a review
• A Neptune-mass Free-floating Planet Candidate Discovered by Microlensing Surveys
• The age-velocity dispersion relation of the Galactic discs from LAMOST-Gaia data
• CFBDSIR2149-0403: a 4-7 Jupiter-mass free-floating planet in the young moving group AB Doradus ?
• Self-Lensing Models of the LMC
• BANYAN. IX. The Initial Mass Function and Planetary-Mass Object Space Density of the TW Hya Association
• Two new free-floating or wide-orbit planets from microlensing
• Candidate free-floating super-Jupiters in the young sigma Orionis open cluster
• Microlensing of Large Sources
• Rapid Formation of Super-Earths around M Dwarf Stars
• Occultation and Microlensing
• The Ultracool SpeXtroscopic Survey. I. Volume-Limited Spectroscopic Sample and Luminosity Function of M7$-$L5 Ultracool Dwarfs
• Microlensing Characterization of Wide-Separation Planets
• Microlensing towards the SMC: a new analysis of OGLE and EROS results
• Free-floating planets from core accretion theory: microlensing predictions
• Gravitational Microlensing: A Tool for Detecting and Characterizing Free-Floating Planets
• The Demographics of Rocky Free-Floating Planets and their Detectability by WFIRST
• LMC Self-lensing from a new perspective
• Measuring the Galactic Distribution of Transiting Planets with WFIRST
• Prediction on detection and characterization of Galactic disk microlensing events by LSST
• KMT-2017-BLG-2820 and the Nature of the Free-Floating Planet Population
• The EROS2 search for microlensing events towards the spiral arms: the complete seven season results
• Reddening map and recent star formation in the Magellanic Clouds based on OGLE IV Cepheids
• A free-floating or wide-orbit planet in the microlensing event OGLE-2019-BLG-0551
• The Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE): The Dust Extinction Curve from Red Clump Stars
• Understanding EROS2 observations toward the spiral arms within a classical Galactic model framework
• Theoretical models of planetary system formation. II. Post-formation evolution
• Estimating Finite Source Effects in Microlensing Events due to Free-Floating Planets with the Euclid Survey
• On the Feasibility of Characterizing Free-floating Planets with Current and Future Space-based Microlensing Surveys
• Microlensing by Compact Objects associated to Gas Clouds
• OGLE-2016-BLG-1227L: A Wide-separation Planet from a Very Short-timescale Microlensing Event
• JVLA Observations of Young Brown Dwarfs
• Short-duration lensing events: I. wide-orbit planets? free-floating low-mass objects? or high-velocity stars?
• The microlensing rate and distribution of free-floating planets towards the Galactic bulge
• ROME/REA: A gravitational microlensing search for exo-planets beyond the snow-line on a global network of robotic telescopes
• OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
• Microlensing in the Small Magellanic Cloud: Lessons from an N-body Simulation
• New Self-lensing Models of the Small Magellanic Cloud: Can Gravitational Microlensing Detect Extragalactic Exoplanets?
• Microlensing of radially pulsating stars
• The advantages of using a Lucky Imaging camera for observations of microlensing events
• Parallax in microlensing toward the Magellanic Clouds: effect on detection efficiency and detectability
• Simulation of a strategy for the pixel lensing of M87 using the Hubble Space Telescope

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• Improved Aberth-Ehrlich root-finding algorithm and its further application for Binary Microlensing
• Numerically studying the degeneracy problem in extreme finite-source microlensing events
• Identifying low-amplitude pulsating stars through microlensing observations
• Variation of the stellar color in high-magnification and caustic-crossing microlensing events
• Mass-velocity dispersion relation by using the \textit{Gaia} data and its effect on interpreting short-duration and degenerate microlensing events