Implication of the Shape of the EDGES Signal for the 21 cm Power Spectrum

Abstract

We revisit the 21 cm power spectrum from the epoch of cosmic dawn in light of the recent EDGES detection of the 21 cm global signal at frequencies corresponding to $z\sim 20$. The shape of the signal suggests that the spin temperature of neutral hydrogen was coupled to the kinetic temperature of the gas relatively rapidly ($19\lesssim z\lesssim 21$). We therefore consider models in which the UV photons were dominantly produced in the rarest and most massive halos ($M\gtrsim 10^9{M}_{\odot }$), since their abundance grows fast enough at those redshifts to account for this feature of the signal. We show that these models predict large power spectrum amplitudes during the inhomogeneous coupling, and then inhomogeneous heating by CMB and Lyman-$\alpha$ photons due to the large shot noise associated with the rare sources. The power spectrum is enhanced by more than an order of magnitude compared to previous models which did not include the shot noise contribution, making it a promising target for upcoming radio interferometers that aim to detect high-redshift 21 cm fluctuations.

arXiv comment6 pages, 5 figures

References in corpus (20)

• Planck 2015 results. XIII. Cosmological parameters
• Ellipsoidal collapse and an improved model for the number and spatial distribution of dark matter haloes
• An absorption profile centred at 78 megahertz in the sky-averaged spectrum
• 21-cm cosmology
• Possible interaction between baryons and dark-matter particles revealed by the first stars
• Formation of the First Stars
• Insights on Dark Matter from Hydrogen during Cosmic Dawn
• Detecting the Earliest Galaxies Through Two New Sources of 21cm Fluctuations
• Enhanced global signal of neutral hydrogen due to excess radiation at cosmic dawn
• Severely Constraining Dark Matter Interpretations of the 21-cm Anomaly
• Charting the Parameter Space of the Global 21-cm Signal
• The signature of the first stars in atomic hydrogen at redshift 20
• New Physics in the Rayleigh-Jeans Tail of the CMB
• Too Hot, Too Cold or Just Right? Implications of a 21-cm Signal for Dark Matter Annihilation and Decay
• 21 cm signal from cosmic dawn: Imprints of spin temperature fluctuations and peculiar velocities
• Constraining Primordial Black Holes with the EDGES 21-cm Absorption Signal
• The simulated 21 cm signal during the epoch of reionization : full modeling of the Ly-alpha pumping
• Complete history of the observable 21-cm signal from the first stars during the pre-reionization era
• Light cone anisotropy in 21 cm signal from the epoch of reionization
• Distinctive rings in the 21 cm signal of the epoch of reionization

Cited by in corpus (23)

• Modeling the Radio Background from the First Black Holes at Cosmic Dawn: Implications for the 21 cm Absorption Amplitude
• Signature of Excess Radio Background in the 21-cm Global Signal and Power Spectrum
• Tighter Limits on Dark Matter Explanations of the Anomalous EDGES 21cm Signal
• Testing for calibration systematics in the EDGES low-band data using Bayesian model selection
• The redshifted 21-cm signal in the EDGES low-band spectrum
• The 21 cm Power Spectrum from the Cosmic Dawn: First Results from the OVRO-LWA
• An Introductory Review on Cosmic Reionization
• Dark Matter microphysics and 21 cm observations
• Bounds on Ultra-Light Hidden-Photon Dark Matter from 21cm at Cosmic Dawn
• A hint on the metal-free star formation rate density from 21cm-EDGES data
• Structure Formation and the Global 21-cm Signal in the Presence of Coulomb-like Dark Matter-Baryon Interactions
• Shot noise and scatter in the star formation efficiency as a source of 21-cm fluctuations
• The importance of stochasticity in determining galaxy emissivities and UV LFs during cosmic dawn and reionization
• Cosmic Variance of the 21-cm Global Signal
• Impact of EDGES 21cm Global Signal on Primordial Power Spectrum
• Edges and Endpoints in 21-cm Observations from Resonant Photon Production
• Constraining structure formation using EDGES
• The EDGES measurement disfavors an excess radio background during the cosmic dawn
• Mapping discrete galaxies at cosmic dawn with 21-centimeter observations
• Rapid onset of the 21-cm signal suggests a preferred mass range for dark matter particle
• Black holes at cosmic dawn in the redshifted 21cm signal of HI
• Global 21cm Absorption Signal from Superconducting Cosmic Strings
• Implications of the cosmological 21-cm absorption profile for high-redshift star formation and deep JWST surveys