Poster Abstract

P5.7 Helga Denes (ASTRON)

Theme: Delivering accessible and science-ready radio data

Uncovering the gas content of galaxies with Apertif

Neutral hydrogen (HI) is the most basic building block of galaxies and an excellent tracer of various processes influencing galaxy evolution. So far, large HI surveys were carried out with low-resolution, single-dish telescopes and only a relatively small sample of nearby galaxies was mapped with high spatial resolution. Only recently, the advancement of new technology, such as phased-array feeds on radio telescopes made it possible to efficiently survey large portions of the sky with interferometric arrays and observe thousands of galaxies in high spatial and spectral resolution. This makes it possible to study the gas content, kinematics and evolution of large samples of galaxies in unprecedented detail. One of these new instruments is Apertif on the Westerbork Synthesis Radio Telescope, currently conducting continuum and HI surveys on a quarter of the northern sky. These surveys will provide us with detailed maps of the HI and the continuum emission of thousands of galaxies. However, these surveys also mean new approaches and challenges with handling large data volumes, starting from the raw data up to the final, science ready data products. I will present our experience so far with the Apertif Imaging Survey focusing on the spectral line data. I will describe how we produce the final spectral line data cubes, the quality testing that we do on them and highlight some of our first results from the survey.