The imprint of the cosmic supermassive black hole growth history on the 21 cm background radiation

Abstract

The redshifted 21 cm transition line of hydrogen tracks the thermal evolution of the neutral intergalactic medium (IGM) at "cosmic dawn," during the emergence of the first luminous astrophysical objects (~100 Myr after the Big Bang) but before these objects ionized the IGM (~400-800 Myr after the Big Bang). Because X-rays, in particular, are likely to be the chief energy courier for heating the IGM, measurements of the 21 cm signature can be used to infer knowledge about the first astrophysical X-ray sources. Using analytic arguments and a numerical population synthesis algorithm, we argue that the progenitors of supermassive black holes (SMBHs) should be the dominant source of hard astrophysical X-rays---and thus the primary driver of IGM heating and the 21 cm signature---at redshifts $z<20$, if (i) they grow readily from the remnants of Population III stars and (ii) produce X-rays in quantities comparable to what is observed from active galactic nuclei and high-mass X-ray binaries. We show that models satisfying these assumptions dominate over contributions to IGM heating from stellar populations, and cause the 21 cm brightness temperature to rise at $z>20$. An absence of such a signature in the forthcoming observational data would imply that SMBH formation occurred later (e.g. via so-called direct collapse scenarios), that it was not a common occurrence in early galaxies and protogalaxies, or that it produced far fewer X-rays than empirical trends at lower redshifts, either due to intrinsic dimness (radiative inefficiency) or Compton-thick obscuration close to the source.

9 pages, 2 figures, submitted to MNRAS

References in corpus (28)

• A luminous quasar at a redshift of z = 7.085
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• An Observational Determination of the Bolometric Quasar Luminosity Function
• Formation of Supermassive Black Holes by Direct Collapse in Pregalactic Halos
• Supermassive black hole formation during the assembly of pre-galactic discs
• Protostar Formation in the Early Universe
• Primordial Star Formation under the Influence of Far Ultraviolet Radiation: 1540 Cosmological Halos and the Stellar Mass Distribution
• Formation of z ~ 6 quasars from hierarchical galaxy mergers
• Discovery of three z>6.5 quasars in the VISTA Kilo-degree Infrared Galaxy (VIKING) survey
• The Global 21 Centimeter Background from High Redshifts
• Accretion onto the First Stellar Mass Black Holes
• Super-Critical Growth of Massive Black Holes from Stellar-Mass Seeds
• Evolution of the 21 cm signal throughout cosmic history
• The case for super-critical accretion onto massive black holes at high redshift
• Feedback-regulated Super Massive Black Hole Seed Formation
• The X-ray spectra of the first galaxies: 21cm signatures
• Toward Empirical Constraints on the Global Redshifted 21 cm Brightness Temperature During the Epoch of Reionization
• How realistic UV spectra and X-rays suppress the abundance of direct collapse black holes
• Decoding the X-ray Properties of Pre-Reionization Era Sources
• Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged λ21 cm Signal at z~20
• The Scattering of Lyman-series Photons in the Intergalactic Medium
• The formation and gas content of high redshift galaxies and minihalos
• The suppression of direct collapse black hole formation by soft X-ray irradiation
• Star Clusters Around Recoiled Black Holes in the Milky Way Halo
• The First Stars: formation under X-ray feedback
• Radiation from early black holes - I: effects on the neutral inter-galactic medium
• Driving the Growth of the Earliest Supermassive Black Holes with Major Mergers of Host Galaxies
• Can the 21 cm signal probe Population III and II star formation?

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• The Assembly of the First Massive Black Holes
• Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries
• Modeling the Radio Background from the First Black Holes at Cosmic Dawn: Implications for the 21 cm Absorption Amplitude
• Titans of the Early Universe: The Prato Statement on the Origin of the First Supermassive Black Holes
• What does the first highly-redshifted 21-cm detection tell us about early galaxies?
• The Global 21-cm Signal in the Context of the High-z Galaxy Luminosity Function
• Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
• Results from EDGES High-Band: I. Constraints on Phenomenological Models for the Global $21$ cm Signal
• Constraining primordial black holes as dark matter using the global 21-cm signal with X-ray heating and excess radio background
• Unique Signatures of Population III Stars in the Global 21-cm Signal
• Signatures of primordial black holes as seeds of supermassive black holes
• The Radio Scream from Black Holes at Cosmic Dawn: A Semi-Analytic Model for the Impact of Radio Loud Black-Holes on the 21 cm Global Signal
• Formation of the first star clusters and massive star binaries by fragmentation of filamentary primordial gas clouds
• Intermediate-mass black holes from Population III remnants in the first galactic nuclei
• Primordial Black Hole Dark Matter in the Context of Extra Dimensions
• Cosmological 21cm line observations to test scenarios of super-Eddington accretion on to black holes being seeds of high-redshifted supermassive black holes