FNWI --- IMAPP Department of Astrophysics
Radboud University > Faculty of Science > Department of Astrophysics

Dark ages EXplorer (DEX) is a low frequency radio interferometer in space or on the Moon, that will probe deep into the early universe and provide an unprecedented detailed view of the evolution of the first structures in the universe. DEX is sensitive in the 1­‐80 MHz regime which allows a study of the Dark Ages and Cosmic Dawn period, with observation of the global neutral hydrogen(21 cm) emission in arcmin scales. This will constrain models on the evolution of the early universe, and the onset of the epoch of reionization which were followed the from the Planck mission. In addition, DEX will open up the last virtually unexplored frequency regime below 30 MHz, extending the view of large ground based radio arrays such as LOFAR and SKA to the ultra long wavelength regime that is not accessible from Earth. Among a wealth of science cases by DEX are also the high resolution low frequency sky maps which constrain models on the jet power in radio galaxies, observe auroral emission from the large planets in our solar system and possibly find Jupiter like exoplanets. DEX requires a large collecting area in the order of 10 km2 (105 individual elements) and a location (preferably the lunar far side) that provides shielding from man made radio interference(RFI), absence of ionospheric distortions, and high temperature and antenna gain stability. The realization of large collecting area interferometers has been achieved on earth already (e.g. LOFAR and in the near future SKA) and the technique behind it is well developed. The realization in space or on the Moon is a very challenging task. However, we are convinced that given the technology developments, especially in the areas of nano satellites, RF technology and low power and high performance computing, the construction of a large low frequency radio array in space or on the Moon is feasible in the 2020- 2030 timeframe. You can find more about DEX in the white paper submitted to the ESA Call for the definition of L2 and L3 missions in the ESA science program.


DEX White Paper