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Characterization of Cosmic Dawn through Observations of the Redshifted 21-cm Line with EDGES

Event Details

Event Dates: 

Friday, September 11, 2015 - 12:00pm

Seminar Location: 

  • JILA 10th Floor - Foothills Room

Speaker Name(s): 

Raul Monsalve

Speaker Affiliation(s): 

Seminar Type/Subject

Scientific Seminar Type: 

  • Astrophysics Lunch Seminar

Event Details & Abstract: 

One way of tracking the formation of the first generations of compact objects in the Universe during the period of Cosmic Dawn and the Epoch of Reionization (EoR) (35 > z > 6) is through observations of the 21-cm line emitted by neutral atomic hydrogen (HI) in the intergalactic medium due to the hyperfine splitting of its ground state. Models have been developed for this observable and precise estimation of their parameters would allow constraining the fundamental physics of structure formation in the early Universe. The cosmological HI signal was emitted at ~ 1.4 GHz but its detection is expected in the VHF range (between 40 and 200 MHz) due to cosmic expansion. The models suggest that the signal is extremely weak, about four orders of magnitude weaker than the relevant foregrounds, making its detection a daunting endeavor. This talk will describe EDGES (Experiment to Detect the Global EoR Signature), an instrument developed by Arizona State University and MIT currently operating in the desert of Western Australia. It attempts to detect the large-scale HI signal from Cosmic Dawn and the EoR following a single-antenna approach and relying on extremely accurate absolute calibration. The talk will present data recently taken, will describe the processing pipeline, and will discuss the status of the science analysis.