Hunting gravitational wave black holes with microlensing

Abstract

Gravitational microlensing is a powerful tool to search for a population of invisible black holes (BHs) in the Milky Way (MW), including isolated BHs and binary BHs at wide orbits that are complementary to gravitational wave observations. By monitoring highly populated regions of source stars like the MW bulge region, one can pursue microlensing events due to these BHs. We find that if BHs have a Salpeter-like mass function extended beyond $30M_{\odot }$ and a similar velocity and spatial structure to stars in the Galactic bulge and disk regions, the BH population is a dominant source of the microlensing events at long timescales of the microlensing light curve $\gtrsim 100$days. This is due to a boosted sensitivity of the microlensing event rate to lens mass, given as $M^2$, for such long-timescale events. A monitoring observation of $2\times 10^{10}$ stars in the bulge region over 10 years with the Rubin Observatory Legacy Survey of Space and Time (LSST) would enable one to find about $6\times 10^5$ BH microlensing events. We evaluate the efficiency of potential LSST cadences for characterizing the light curves of BH microlensing and find that nearly all events of long timescales can be detected.

arXiv comment16 pages, 8 figures: accepted for publication in ApJ

References in corpus (57)

• Observation of Gravitational Waves from a Binary Black Hole Merger
• Gaia Data Release 2. Summary of the contents and survey properties
• On the variation of the Initial Mass Function
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• GWTC-1: A Gravitational-Wave Transient Catalog of Compact Binary Mergers Observed by LIGO and Virgo during the First and Second Observing Runs
• GW190814: Gravitational Waves from the Coalescence of a 23 M${}_{\odot }$ Black Hole with a 2.6 M${}_{\odot }$ Compact Object
• Mass-loss predictions for O and B stars as a function of metallicity
• GW190425: Observation of a Compact Binary Coalescence with Total Mass $\sim 3.4M_{\odot }$
• Masses, Radii, and Equation of State of Neutron Stars
• GW170608: Observation of a 19-solar-mass Binary Black Hole Coalescence
• Did LIGO detect dark matter?
• The MACHO Project: Microlensing Results from 5.7 Years of LMC Observations
• A Comprehensive Study of Binary Compact Objects as Gravitational Wave Sources: Evolutionary Channels, Rates, and Physical Properties
• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• Primordial Black Hole Scenario for the Gravitational-Wave Event GW150914
• The first gravitational-wave source from the isolated evolution of two 40-100 Msun stars
• Binary Black Hole Population Properties Inferred from the First and Second Observing Runs of Advanced LIGO and Advanced Virgo
• Black hole mergers in the universe
• Discovery of a Cool Planet of 5.5 Earth Masses Through Gravitational Microlensing
• Microlensing constraints on primordial black holes with the Subaru/HSC Andromeda observation
• Unbound or Distant Planetary Mass Population Detected by Gravitational Microlensing
• Secular evolution of compact binaries near massive black holes: gravitational wave sources and other exotica
• Constraints on Earth-mass primordial black holes from OGLE 5-year microlensing events
• Streams, substructures and the early history of the Milky Way
• Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing
• Intermediate mass black holes in AGN disks: I. Production & Growth
• No large population of unbound or wide-orbit Jupiter-mass planets
• The Mass Distribution of Stellar Black Holes
• Evolution of Binary Compact Objects Which Merge
• Hierarchical Black Hole Mergers in Active Galactic Nuclei
• Discovery of a Candidate Black Hole - Giant Star Binary System in the Galactic Field
• A Natural Formalism for Microlensing
• Microlensing optical depth towards the Galactic bulge from MOA observations during 2000 with Difference Image Analysis
• The Milky Way Tomography with SDSS: III. Stellar Kinematics
• Probing The Lower Mass Limit for Supernova Progenitors and the High-Mass End of the Initial-Final Mass Relation from White Dwarfs in the Open Cluster M35 (NGC 2168)
• The Mass Spectrum Of Machos From Parallax Measurements
• Masses and Orbital Constraints for the OGLE-2006-BLG-109Lb,c Jupiter/Saturn Analog Planetary System
• Black Hole, Neutron Star and White Dwarf Candidates from Microlensing with OGLE-III
• Systematic Analysis of 22 Microlensing Parallax Candidates
• Gravitational Microlensing Events Due to Stellar Mass Black Holes
• Exploring Primordial Black Holes from the Multiverse with Optical Telescopes
• Constraining the masses of microlensing black holes and the mass gap with Gaia DR2
• Optical Gravitational Lensing Experiment. OGLE-1999-BUL-32: the Longest Ever Microlensing Event -- Evidence for a Stellar Mass Black Hole?
• OGLE-III Microlensing Events and the Structure of the Galactic Bulge
• Statistical Determination of the MACHO Mass Spectrum
• The Birth Function for Black Holes and Neutron Stars in Close Binaries
• Two new free-floating or wide-orbit planets from microlensing
• Mass Determination With Gravitational Microlensing
• A Search for Stellar-Mass Black Holes via Astrometric Microlensing
• On the wave optics effect on primordial black hole constraints from optical microlensing search
• PopSyCLE: A New Population Synthesis Code for Compact Object Microlensing Events
• On the accuracy of mass measurement for microlensing black holes as seen by Gaia and OGLE
• Optical Depths and Timescale Distributions in Galactic Microlensing
• Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye
• Microlensing optical depth and event rate in the OGLE-IV Galactic plane fields
• A Machine Learning Classifier for Microlensing in Wide-Field Surveys
• Primordial Black Hole Microlensing: The Einstein Crossing Time Distribution

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• Multi-wavelength emission from magnetically arrested disks around isolated black holes
• Lens parameters for Gaia18cbf -- a long gravitational microlensing event in the Galactic plane
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• Detection Prospects of Electromagnetic Signatures from OGLE-2011-BLG-0462