A critical analysis of the recent OGLE limits on stellar mass primordial black holes in the halo of the Milky Way

Abstract

This paper is a response to recent claims that a population of primordial black holes in the Galactic halo has been ruled out by the OGLE collaboration. This claim was based on the latest results from the OGLE microlensing survey towards the Large Magellanic Cloud which failed to detect even the number of events expected from known stellar populations. In particular, their results are completely inconsistent with the results of the MACHO survey which detected a population of compact bodies in the Galactic halo which could not be accounted for by any known stellar population. The discrepancy between the results of these two groups has a long history, and includes problems such as different choice of photometric passbands, quality of light curves, microlensing event selection, detection efficiency, self lensing and halo models. In this paper it is demonstrated that these issues not only account for the discrepancy between the OGLE and MACHO results, but imply that the OGLE observations can put no meaningful constraints on a population of primordial black holes in the Galactic halo.

arXiv comment8 pages, 4 figures

References in corpus (28)

• The MACHO Project: Microlensing Results from 5.7 Years of LMC Observations
• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• Possible Gravitational Microlensing of a Star in the Large Magellanic Cloud
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• The MACHO Project LMC Microlensing Results from the First Two Years and the Nature of the Galactic Dark Halo
• The Circular Velocity Curve of the Milky Way from $5$ to $25$ kpc
• The Milky Way total mass profile as inferred from Gaia DR2
• Cosmic Conundra Explained by Thermal History and Primordial Black Holes
• Stellar Contribution to the Galactic Bulge Microlensing Optical Depth
• Observational Evidence for Primordial Black Holes: A Positivist Perspective
• Rotation Curve and Mass Distribution in the Galactic Center --- From Black Hole to Entire Galaxy ---
• The MACHO Project First Year LMC Results: The Microlensing Rate and the Nature of the Galactic Dark Halo
• Calibration of the MACHO Photometry Database
• Rotation Curve of the Milky Way out to $\sim$ 200 kpc
• The OGLE View of Microlensing towards the Magellanic Clouds. III. Ruling out sub-solar MACHOs with the OGLE-III LMC data
• No massive black holes in the Milky Way halo
• Updating the MACHO fraction of the Milky Way dark halo with improved mass models
• The OGLE View of Microlensing towards the Magellanic Clouds. I. A Trickle of Events in the OGLE-II LMC data
• The signature of primordial black holes in the dark matter halos of galaxies
• Microlensing optical depth and event rate toward the Large Magellanic Cloud based on 20 years of OGLE observations
• A new look at microlensing limits on dark matter in the Galactic halo
• LMC Self-lensing from a new perspective
• The MACHO Project Hubble Space Telescope Follow-Up: Preliminary Results on the Location of the Large Magellanic Cloud Microlensing Source Stars
• LMC self lensing for OGLE-II microlensing observations
• Microlensing towards M31 with MDM data
• SDSS J1004+4112: the case for a galaxy cluster dominated by primordial black holes
• The MEMO project: Combining all microlensing surveys to search for intermediate-mass Galactic black holes
• Fast Computational Convolution Methods For Extended Source Effects In Microlensing Lightcurves

Cited by in corpus (3)

• Primordial black holes: constraints, potential evidence and prospects
• Primordial Black Holes Formation Beyond the Standard Cosmic QCD Transition
• The Dark Side of the Moon: Listening to Scalar-Induced Gravitational Waves