Speaker
Description
The Sun is an extended, bright and variable source. Solar radio emission of our interest is often brief and intense, with a typical duration of a few seconds and a flux exceeding $10^7$ Jy. Due to these features, one can only use the brightest calibrators during calibration and cannot benefit from a long integration time for solar observations. This talk presents a new calibration method incorporating a sun model to improve the calibration. Usually, calibration of LOFAR solar data consists of two steps: (1) calibration of the ‘quiet’ Sun without significant radio bursts using a bright calibrator (as a calibration reference); (2) transfer of solutions from the ‘quiet’ Sun to the Sun flares. The new method creates a model of the ‘quiet’ Sun during the first phase. Subsequently, the Sun model is combined with the existing calibrator model, Cassiopeia A, to calibrate the ‘quiet’ Sun. We compare the ‘quiet’ and Sun flare images based on different calibration strategies with or without the Sun model to demonstrate if there is an improvement.
