Center for Astrophysics Research and Technologies Seminar Series
Searching for the 21 cm Cosmic Dawn Signal with the Long Wavelength Array
Presented by Chris DiLullo (UNM)
The hunt is on around the world to detect the signature from the 21 cm hyperfine transition of neutral hydrogen during the formation of the first stars. This period in the Universe's history, known as Cosmic Dawn, marks the end of the Dark Ages and the beginning of the Epoch of Reionization. The signature should show in absorption against the Cosmic Microwave Background and is expected to be redshifted to frequencies below 100 MHz. In 2018, the Experiment to Detect the Global EoR Signature (EDGES) collaboration reported a potential detection of an absorption feature in the sky averaged spectrum centered at 78 MHz. In this talk, I will discuss an ongoing effort to validate this finding using the Long Wavelength Array station located on the Sevilleta National Wildlife Refuge (LWA-SV). LWA-SV offers beamforming capabilities that set it apart from other experiments searching for Cosmic Dawn. I will review previous work and system limits and then discuss new methods that have led to improved limits. I will conclude by discussing a new achromatic beamforming technique for LWA-SV that has been developed and is currently in testing.
2:00 pm, Thursday, October 1, 2020
Zoom,
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