Using Artificial Neural Networks to extract the 21-cm Global Signal from the EDGES data

Abstract

The redshifted 21-cm signal of neutral Hydrogen is a promising probe into the period of evolution of our Universe when the first stars were formed (Cosmic Dawn), to the period where the entire Universe changed its state from being completely neutral to completely ionized (Reionization). The most striking feature of this line of neutral Hydrogen is that it can be observed across an entire frequency range as a sky-averaged continuous signature, or its fluctuations can be measured using an interferometer. However, the 21-cm signal is very faint and is dominated by a much brighter Galactic and extra-galactic foregrounds, making it an observational challenge. We have used different physical models to simulate various realizations of the 21-cm Global signals, including an excess radio background to match the amplitude of the EDGES 21-cm signal. First, we have used an artificial neural network (ANN) to extract the astrophysical parameters from these simulated datasets. Then, mock observations were generated by adding a physically motivated foreground model and an ANN was used to extract the astrophysical parameters from such data. The $R^2$ score of our predictions from the mock-observations is in the range of 0.65-0.89. We have used this ANN to predict the signal parameters giving the EDGES data as the input. We find that the reconstructed signal closely mimics the amplitude of the reported detection. The recovered parameters can be used to infer the physical state of the gas at high redshifts.

Submitted to MNRAS

References in corpus (14)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Keeping the Universe ionised: Photo-heating and the clumping factor of the high-redshift intergalactic medium
• The CMBR fluctuations from HI perturbations prior to reionization
• 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
• BIGHORNS - Broadband Instrument for Global HydrOgen ReioNisation Signal
• The Effects of Dark Matter Decay and Annihilation on the High-Redshift 21 cm Background
• 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
• Emulation of reionization simulations for Bayesian inference of astrophysics parameters using neural networks
• The Effects of Population III X-ray and Radio Backgrounds on the Cosmological 21-cm Signal
• Radio background and IGM heating due to Pop III supernovae explosions
• Ruling out 3 keV warm dark matter using 21 cm-EDGES data
• 21cm Global Signal Extraction: Extracting the 21cm Global Signal using Artificial Neural Networks

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• Studying Cosmic Dawn using redshifted HI 21-cm signal: A brief review
• Extracting the 21-cm Power Spectrum and the reionization parameters from mock datasets using Artificial Neural Networks
• Exploring the cosmic dawn and epoch of reionization with 21cm line
• In search of an interaction in the dark sector through Gaussian Process and ANN approaches
• Extracting the Global 21-cm signal from Cosmic Dawn and Epoch of Reionization in the presence of Foreground and Ionosphere
• Detection of Dipole Modulation in CMB Temperature Anisotropy Maps from WMAP and Planck using Artificial Intelligence
• Probing the Epoch of Reionization using synergies of line intensity mapping
• Comparing sampling techniques to chart parameter space of 21 cm Global signal with Artificial Neural Networks
• Synthetic Observations with the Square Kilometre Array (SKA) -- development towards an end-to-end pipeline
• Impact of Calibration and Position Errors on Astrophysical Parameters of the HI 21cm Signal
• Exploring Machine Learning Regression Models for Advancing Foreground Mitigation and Global 21cm Signal Parameter Extraction
• Accelerating reionization constraints: An ANN-emulator framework for the SCRIPT Semi-numerical Model
• Cosmological bounds on dark matter annihilation using dark ages 21-cm signal