Princeton Plasma Physics Laboratory (PPPL) Colloquium

Observations of redshifted 21-cm emission of neutral hydrogen over a wide range of radio frequencies allow us to access redshifts that encompass a vast comoving volume, including the era of dark energy. In this talk, I will present the Hydrogen Intensity Mapping and Real time Analysis eXperiment (HIRAX) project, which is a proposed 21cm intensity mapping experiment operating at 400-800 MHz that will measure the evolution of dark energy over the redshift range z=0.8-2.5 by using the characteristic baryonic acoustic oscillation scale as a standard ruler. The HIRAX radio telescope array will be sited in the radio-quiet Karoo astronomy reserve in South Africa and will ultimately comprise 1024 dishes, each six metres in diameter, placed in a compact configuration. I will discuss the design and project status of HIRAX, its scientific prospects and engineering challenges. This includes dark energy forecasts as well as prospects for interesting cosmological constraints from cross-correlations of HIRAX data with other large-area cosmological surveys in the southern sky. HIRAX will also discover a large number of pulsars and transients, including fast radio bursts (FRBs). I will describe our programme to localise these FRBs using HIRAX outriggers in African partner countries.