Members of the ASKAP FLASH team at the FLASH Splash, May 2026.

The First Large Absorption line Survey in HI (FLASH) is a wide-area survey using ASKAP to search for the 21cm neutral hydrogen (HI) line in absorption against background radio continuum sources. FLASH observations are carried out using the lowest ASKAP frequency band (711.5–999.5 MHz) providing information on the HI content of the Universe between redshifts z=0.42 and z=1.0, covering look-back times from 4 to 8 billion years ago. The science goals of the FLASH survey include determining how the cool HI gas in galaxies has evolved since cosmic noon and examining the gas accretion mechanisms that drive the co-evolution of supermassive black holes and their host galaxies over cosmic history. This month, the FLASH team is wrapping up their observing time with ASKAP and entering the next phase of analysing and interpreting the huge amounts of data. To celebrate this event, a “FLASH Splash” was held last week at Marsfield and on-line, with presentations covering ASKAP, the FLASH survey, and examples of FLASH science. The image above shows members of the ASKAP team, both those present in person and those behind them attending on-line.