Due to the challenging nature of high frequency radio surveys, few have been performed, resulting in a poor knowledge of the high frequency radio source population. The Arcminute MicroKelvin Imager Small Array (AMI-SA) is now conducting a legacy survey of the complete Northern hemisphere at 15 GHz. This is the highest frequency survey conducted to date of the whole Northern hemisphere to a source detection level of 10 mJy. This project involved understanding of the calibration and imaging process of the AMI-SA drift scan data which were used to combine the different scans into a continuous map. The continuous maps were stitched together to generated larger maps of the Northern hemisphere and these maps were searched for sources and when the survey is completed a catalogue will be compiled. Modifications of the data pipeline were investigated with the aim to improved image quality through implementing self-calibration techniques to remove artefacts round bright sources. It was discovered that self-calibration significantly improved the image quality over what could be achieved with interleaved observations of a bright calibrator source, and the data reduction pipeline will be changed to include such a self-calibration step as standard. In future, identified sources will be followed up by observations with the AMI-LA to match NVSS resolution. A comparison of these results with NVSS will allow calculation of the radio spectral index distribution between 1.4 and 15 GHz and identification of any currently undiscovered inverted spectrum sources.
|Date of Award||1 Aug 2022|
- The University of Manchester
|Supervisor||Keith Grainge (Supervisor) & Anna Scaife (Supervisor)|