1 Scientific Motivation

This workshop brought together 43 astronomers within the LOw Frequency ARray (LOFAR) survey team to exchange expertise and ideas on how to reduce and analyse LOFAR data. LOFAR is a new interferometric array based in the Netherlands, but with international stations, that operates between 10 and 250 MHz, opening a new frequency regime to astronomers. The main challenge with LOFAR imaging 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. This requires resolution of serious issues that were being addressed by working groups of 4-8 people. The workshop started with a review of the entire status of the system and associated software before breaking into working groups. The entire body of participants reconvened each day for a status update.


2 Scientific Outcome

The topics of the working groups are listed here along with the results from the work conducted within the scope of this workshop.

-       Long Baseline Observations: Developed a complete method for how to process long baseline observations.

-       Ionospheric Effects: Methods of measuring ionospheric effects and subtract its imprint from the scientific data were demonstrated. Possible software implementation of these methods in the data reduction pipeline have been tested.

-       Large Scale Galactic Structures: Structured a method to effectively test the demixing (removal) of strong sources in the sidebands of observations.

-       Source Flux Recovery: Tested the new imaging software against the old, and also tested two different types of source extractors. LOFAR appears to be recovering source fluxes very well within the central _2 degrees of the field of view.

-       Cookbook Tutorial: Wrote a tutorial to help new users to the instrument.

-       Deep Field XMM-LSS: Produced the first images from LOFAR of the XMM-LSS field, showing that low-elevation observations are possible with the High Band Antenna (HBA) component of LOFAR.


Overall, the workshop was a success not only for the individual working groups but for the larger group as well, with discussions on how to proceed and work more effectively towards creating the best images possible of the low frequency radio sky with LOFAR.


3 Organization/Format

The space provided in the Snellius Building worked exceptionally well for the program. The large space for lectures held everyone, yet there were enough offices and smaller working areas for the splinter groups to gather and be productive. Every group utilized (and loved!) the chalkboard/whiteboard walls. In addition, the way the program coordinators responded to an evacuation of the building was wonderful. Within half an hour they had found another venue for the day and arranged lunch and then snacks and drinks for later on. Many participants commented on how well the workshop recovered from being evacuated.


Emanuela Orru' (Dwingeloo, Netherlands)  

Leah Morabito (Leiden, Netherlands)  

Neal Jackson (Manchester, United Kingdom)  

Huub Röttgering (Leiden, Netherlands)  

Michael Wise (Dwingeloo, Netherlands)