HI absorption surveys: ready to start!

© ASTRON

One of the ways to explore gas in the Universe is using HI absorption observations. The new radio telescopes (ASKAP, MeerKAT and Apertif on the WSRT) offer exciting new possibilities for science using HI absorption. Coordinating the groups planning to exploit these data was one of the motives for a small but very lively workshop held at ASTRON 14th to the 16th of June 2017.

HI absorption observations are complementary to those tracing the HI gas in emission because they allow to detect gas much distant objects and to image the gas at very high spatial resolution, i.e. at parsec scales reachable by VLBI.

The workshop covered a number of important topics, from the status of the new (or upgraded) telescopes, and of the tools to exploit the upcoming surveys, to the science we want to do with the data and the complementarity of the various surveys.

The schedule of the workshop included ample time for discussion. Each session had presentations of participants and was followed by a discussion about open issues. A number of action points have been decided, hopefully providing a better coordination among the various groups. The perfect weather also helped in making sure the discussions could continue outside the building. About forty astronomers attended the workshop, coming from eight different countries (with particularly large groups from Australia and India). About 1/3 of the participants were female and about half were young postDocs and PhD students. In short: a very lively community ready to start exploiting the data beginning to appear from all telescopes including Apertif (see Daily Image 14-06-2017).