Primordial black holes in the Dark Ages: Observational prospects for future 21cm surveys

Abstract

We consider the signatures of a population of primordial black holes (PBHs) in future observations of 21cm radiation from neutral hydrogen at high redshift. We focus on PBHs in the mass range $5\times 10^{10}kg\lesssim M_{PBH}\lesssim 10^{14}kg$, which primarily influence the intergalactic medium (IGM) by heating from direct Hawking radiation. Our computation takes into account the black hole graybody factors and the detailed energy dependence of photon and e+/- absorption by the IGM. We find that for black holes with initial masses between $5\times 10^{11}kg\lesssim M_{PBH}\lesssim 10^{14}kg$, the signal mimics that of a decaying dark matter species. For black holes in the range $5\times 10^{10}kg\lesssim M_{PBH}\lesssim 5\times 10^{11}kg$, the late stages of evaporation produce a characteristic feature in the 21cm brightness temperature that provides a unique signature of the black hole population. If no signal is observed, then 21cm observations will provide significantly better constraints on PBHs in the mass range $5\times 10^{10}kg\lesssim M_{PBH}\lesssim 10^{12}kg$ than are currently available from the diffuse $\gamma$-ray background.

arXiv comment15 pages, 8 figures v2: references added, typos corrected, minor changes

References in corpus (9)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• 21-cm Tomography of the Intergalactic Medium at High Redshift
• A New Calculation of the Recombination Epoch
• Particle decays during the cosmic dark ages
• Measuring the Small-Scale Power Spectrum of Cosmic Density Fluctuations Through 21 cm Tomography Prior to the Epoch of Structure Formation
• 21 cm fluctuations from inhomogeneous X-ray heating before reionization
• The 21cm angular-power spectrum from the dark ages
• The Effects of Dark Matter Decay and Annihilation on the High-Redshift 21 cm Background
• The Physics and Early History of the Intergalactic Medium

Cited by in corpus (26)

• Fundamental Physics with the Square Kilometre Array
• The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
• Cosmological constraints on exotic injection of electromagnetic energy
• Probing the First Stars and Black Holes in the Early Universe with the Dark Ages Radio Explorer (DARE)
• Observing Neutral Hydrogen Above Redshift 6: The "Global" Perspective
• The Effects of Dark Matter-Baryon Scattering on Redshifted 21 cm Signals
• Constraining primordial black holes as dark matter using the global 21-cm signal with X-ray heating and excess radio background
• Primordial black hole constraints with Hawking radiation -- a review
• Signatures of primordial black holes as seeds of supermassive black holes
• The effect of primordial black holes on 21 cm fluctuations
• 21-cm constraints on spinning primordial black holes
• Probing the effects of primordial black holes on 21-cm EDGES signal along with interacting dark energy and dark matter - baryon scattering
• Constraints on the curvature power spectrum from primordial black hole evaporation
• Bounds on abundance of primordial black hole and dark matter from EDGES 21-cm signal
• Evaporating Primordial Black Holes in Gamma Ray and Neutrino Telescopes
• Press-Schechter primordial black hole mass functions and their observational constraints
• Prospects of Future CMB Anisotropy Probes for Primordial Black Holes
• The 21-cm signals from ultracompact minihalos as a probe of primordial small-scale fluctuations
• Distribution of primordial black holes and 21cm signature
• Exploring multimessenger signals from heavy dark matter decay with EDGES 21-cm result and IceCube
• Global 21-cm brightness temperature in viscous dark energy models
• Quantum coherence of photons at cosmological distances
• Constraining PBH mass distributions from 21cm brightness temperature results and an analytical mapping between probability distribution of 21cm signal and PBH masses
• The Hydrogen Mixing Portal, Its Origins, and Its Cosmological Effects
• Primordial Black Holes in non-linear perturbation theory
• It's Always Darkest Before the Cosmic Dawn: Early Results from Novel Tools and Telescopes for 21 cm Cosmology