Workweek: Towards understanding imaging data from LOFAR
LOFAR, the Low Frequency Array, is a next-generation radio telescope that is being built in the Netherlands and neighboring countries. It will carry out a broad range of fundamental astrophysical studies. An important goal of LOFAR is to explore the low-frequency radio sky by means of a series of unique surveys. The main aim of these surveys is to advance our understanding of the formation of galaxies, clusters and active galactic nuclei. These surveys will be carried out and scientifically exploited by a large international science team, consisting of 75 staff astronomers, 20 postdocs and 25 PhD students. Currently LOFAR is in its role-out and commissioning phase. In the middle of February, 32 stations were operational, and with the current projected rate of building, the complete LOFAR facility with 36 Dutch stations and 8 international stations should be ready at the end of 2011. Also the main software pipeline that is capable of delivering maps of the radio sky from the basic data is advancing rapidly. The main challenge for the survey project is to ensure that high dynamic range thermal noise limited images with a stable point-spread function can be made over the entire accessible sky and over LOFAR's full frequency range. The serious issues that need to be tackled before deep and scientifically useful maps can be made include
(i) an efficient usage of the computational resources,
(ii) an effective removal of radio frequency interference (RFI),
(iii) dealing with the corrupting influence of the ionosphere, and,
(iv) properly correcting for the station beams.
To deal with all these issues, the survey team has been and is organizing a series of ‘busy weeks’. The idea is that a team of astronomers from the survey team attempt to tackle a number of issues related to the challenges just mentioned. During these busy weeks functionalities of the system were tested.