Using the Long Wavelength Array to Search for Cosmic Dawn

Abstract

The search for the spectral signature of hydrogen from the formation of the first stars, known as Cosmic Dawn or First Light, is an ongoing effort around the world. The signature should present itself as a decrease in the temperature of the 21-cm transition relative to that of the Cosmic Microwave Background and is believed to reside somewhere below 100 MHz. A potential detection was published by the Experiment to Detect the Global EoR Signal (EDGES) collaboration with a profile centered around 78 MHz of both unexpected depth and width (Bowman et. al 2018; arXiv:1810.05912). If validated, this detection will have profound impacts on the current paradigm of structure formation within $\Lambda$CDM cosmology. We present an attempt to detect the spectral signature reported by the EDGES collaboration with the Long Wavelength Array station located on the Sevilleta National Wildlife Refuge in New Mexico, USA (LWA-SV). LWA-SV differs from other instruments in that it is a 256 element antenna array and offers beamforming capabilities that should help with calibration and detection. We report first limits from LWA-SV and look toward future plans to improve these limits.

16 pages, 12 figures, to be published in Journal of Astronomical Instrumentation

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• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• The Global 21 Centimeter Background from High Redshifts
• BIGHORNS - Broadband Instrument for Global HydrOgen ReioNisation Signal
• Power spectrum extraction for redshifted 21-cm epoch of reionization experiments: the LOFAR case
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Cited by in corpus (10)

• HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
• Mapper of the IGM spin temperature: instrument overview
• Probing Interacting Dark Energy and Scattering of Baryons with Dark Matter in Light of EDGES 21cm Signal
• The All-Sky SignAl Short-Spacing INterferometer (ASSASSIN) I: Global sky measurements with the Engineering Development Array-2
• ETHOS -- An Effective Theory of Structure Formation: Impact of Dark Acoustic Oscillations on Cosmic Dawn
• Transient RFI environment of LOFAR-LBA at 72-75 MHz: Impact on ultra-widefield AARTFAAC Cosmic Explorer observations of the redshifted 21-cm signal
• Scattering Parameter Measurements of the Long Wavelength Array Antenna and Front End Electronics
• Improvements to the Search for Cosmic Dawn Using the Long Wavelength Array
• Design and Commissioning of an LWA Swarm Station: The Long Wavelength Array -- North Arm
• Radio-Frequency Interference at the McGill Arctic Research Station