New evidence for a cosmological distribution of stellar mass primordial black holes

Abstract

In this paper we show that to explain the observed distribution of amplitudes in a large sample of quasar lightcurves, a significant contribution from microlensing is required. This implies the existence of a cosmologically distributed population of stellar mass compact bodies making up a large fraction of the dark matter. Our analysis is based on the lightcurves of a sample of over 1000 quasars, photometrically monitored over a period of 26 years. The intrinsic variations in quasar luminosity are derived from luminous quasars where the quasar accretion disc is too large to be microlensed by stellar mass bodies, and then synthetic lightcurves for the whole sample are constructed with the same statistical properties. We then run microlensing simulations for each quasar with convergence in compact bodies appropriate to the quasar redshift assuming a $\Lambda$CDM cosmology. The synthetic lightcurve is then superimposed on the amplification pattern to incorporate the effects of microlensing. The distribution of the resulting amplitudes can then be compared with observation, giving a very close match. This procedure does not involve optimising parameters or fitting to the data, as all inputs such as lens mass and quasar disc size come from independent observations in the literature. The overall conclusion of the paper is that to account for the distribution of quasar lightcurve amplitudes it is necessary to include the microlensing effects of a cosmologically distributed population of stellar mass compact bodies, most plausibly identified as stellar mass primordial black holes.

9 pages, 9 figures, published in MNRAS

References in corpus (7)

• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
• Timescale of variation and the size of the accretion disc in active galactic nuclei
• The signature of primordial black holes in the dark matter halos of galaxies
• Is there a concordance value for $H_0$?
• A new look at microlensing limits on dark matter in the Galactic halo
• The case for primordial black holes as dark matter
• SDSS J1004+4112: the case for a galaxy cluster dominated by primordial black holes

Cited by in corpus (12)

• Observational Evidence for Primordial Black Holes: A Positivist Perspective
• Primordial Black Holes
• Simulations of PBH formation at the QCD epoch and comparison with the GWTC-3 catalog
• Effects of stellar-mass primordial black holes on first star formation
• Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO
• Primordial black holes: constraints, potential evidence and prospects
• Testing the Cosmological Principle: On the Time Dilation of Distant Sources
• Evidence for microlensing by primordial black holes in quasar broad emission lines
• Multifractality Signatures in Lensed Quasars
• Accurate modelling of extragalactic microlensing by compact objects
• Primordial black holes in the main lensing galaxy of FBQ 0951+2635
• The Dark Side of the Moon: Listening to Scalar-Induced Gravitational Waves