Large Aperture Experiment to Detect the Dark Ages

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Organisation Harvard, UC Berkeley, UNM, Virginia Tech
Location(s) the Long Wavelength Array site, adjacent to the Very Large Array in New Mexico
Coordinates 34°04′08″N 107°37′42″W / 34.06888328°N 107.6283088°W / 34.06888328; -107.6283088Coordinates: 34°04′08″N 107°37′42″W / 34.06888328°N 107.6283088°W / 34.06888328; -107.6283088
Wavelength radio 3.4–10 m (30–88 MHz)
Built in construction
Telescope style dipole antenna array
Diameter 500 m
Angular resolution one to a few deg.
Collecting area ~3000 m²
Mounting fixed

The Large-Aperture Experiment to Detect the Dark Ages (LEDA) is designed to detect the spectrum of the 21 cm Hydrogen line from the Intergalactic Medium (IGM) at redshifts of 15-30, when the Universe was just ~1% of its present age.[1] LEDA principally comprises a "large-N" array correlator (512 inputs over ~ 60 MHz), calibration & imaging system, and instrumentation for measurement of calibrated total-power. These systems will use the station 1 of the Long Wavelength Array as an aperture. LEDA is one of several efforts seeking to study cosmological reionization and the preceding Dark Ages. Others include the Precision Array for Probing the Epoch of Reionization (PAPER), Low Frequency Array (LOFAR), Murchison Widefield Array (MWA), and Giant Metrewave Radio Telescope (GMRT). LEDA will feature array-based calibration to improve the accuracy of foreground subtraction from the total-power signal. The project received funding from the National Science Foundation in August 2011.


  1. ^ Lincoln J. Greenhill and Gianni Bernardi (2012). "HI Epoch of Reionization Arrays". 2011 Asian-Pacific Regional IAU Meeting, NARIT Conference Series 1. arXiv:1201.1700. Bibcode:2012arXiv1201.1700G. 

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