The Ruder Bošković Institute in Zagreb, Croatia, formed the venue for a meeting of the Cosmic Dawn / Epoch of Reionization Science Working Group on 28th and 29th September. About 30 members of the group participated. Many of them would meet again at the IAU Symposium 333 “Peering towards the Cosmic Dawn” which was held in Dubrovnik the week after.
The first day of the meeting was dedicated to presentations of recent developments in SKA, as well in theory and observations with precursors. The second day was used to further develop the Blind Challenge for 21-cm power spectrum extraction codes. The idea is to release a small number of “corrupted” 21-cm image cubes and ask the different teams to report back the 21-cm power spectrum which will then be compared to the chosen input signal, which will be unknown to those submitting results. In this first phase the corruptions will only be noise and foreground signals but in the future they will include instrumental effects, RFI, as well as the ionosphere. This challenge is one of the steps of arriving at a complete end-to-end pipeline for the future measurements with SKA-low.
The meeting was organised by Vibor Jelić and the statue seen in the picture is of professor Balthasar, a cartoon character from the seventies, created in Zagreb. Those of us who know the cartoons surely wish that some of his magic could be applied to our endeavours.