Classification of Radio Backgrounds at Cosmic Dawn and 21 cm Signal Confirmation Using Neural Networks

Abstract

Several ongoing and upcoming radio telescopes aim to detect either the global 21 cm signal or the 21 cm power spectrum. The extragalactic radio background, as detected by ARCADE-2 and LWA-1, suggests a strong radio background from cosmic dawn, which can significantly alter the cosmological 21 cm signal, enhancing both the global signal amplitude and the 21 cm power spectrum. In this paper, we employ an artificial neural network (ANN) to check if there is a radio excess over the cosmic microwave background in mock data, and if present, we classify its type into one of two categories, a background from high-redshift radio galaxies or a uniform exotic background from the early Universe. Based on clean data (without observational noise), the ANN can predict the background radiation type with $96\%$ accuracy for the power spectrum and $90\%$ for the global signal. Although observational noise reduces the accuracy, the results remain quite useful. We also apply ANNs to map the relation between the 21 cm power spectrum and the global signal. By reconstructing the global signal using the 21 cm power spectrum, an ANN can estimate the global signal range consistent with an observed power spectrum from SKA-like experiments. Conversely, we show that an ANN can reconstruct the 21 cm power spectrum over a wide range of redshifts and wavenumbers given the global signal over the same redshifts. Such trained networks can potentially serve as a valuable tool for cross-confirmation of the 21 cm signal.

Revision to match the published version

References in corpus (27)

• Array Programming with NumPy
• 21CMMC: an MCMC analysis tool enabling astrophysical parameter studies of the cosmic 21 cm signal
• Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
• First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
• Signature of Excess Radio Background in the 21-cm Global Signal and Power Spectrum
• LOFAR/H-ATLAS: The low-frequency radio luminosity - star-formation rate relation
• Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
• HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
• The REACH radiometer for detecting the 21-cm hydrogen signal from redshift 7.5 to 28
• Emulation of reionization simulations for Bayesian inference of astrophysics parameters using neural networks
• Tight Constraints on the Excess Radio Background at $z=9.1$ from LOFAR
• High-redshift radio galaxies: a potential new source of 21-cm fluctuations
• The subtlety of Ly-a photons: changing the expected range of the 21-cm signal
• The rich complexity of 21-cm fluctuations produced by the first stars
• The Impact of Foregrounds on Redshift Space Distortion Measurements With the Highly-Redshifted 21 cm Line
• The trispectrum of 21-cm background anisotropies as a probe of primordial non-Gaussianity
• Astrophysical Constraints from the SARAS3 non-detection of the Cosmic Dawn Sky-Averaged 21-cm Signal
• GLOBALEMU: A novel and robust approach for emulating the sky-averaged 21-cm signal from the cosmic dawn and epoch of reionisation
• Radio background and IGM heating due to Pop III supernovae explosions
• Mapper of the IGM spin temperature: instrument overview
• A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
• Cosmic backgrounds due to the formation of the first generation of supermassive black holes
• 21cmVAE: A Very Accurate Emulator of the 21-cm Global Signal
• The Second Radio Synchrotron Background Workshop: Conference Summary and Report
• The role of soft photon injection and heating in 21 cm cosmology
• Emulation of the Cosmic Dawn 21-cm Power Spectrum and Classification of Excess Radio Models Using an Artificial Neural Network
• Mapping discrete galaxies at cosmic dawn with 21-centimeter observations