Large-Scale Structure in C-BASS Data

UoM administered thesis: Master of Science by Research

  • Authors:
  • Saarah Nakhuda


This thesis describes the study of large-scale structure in data from the 5 GHz C-Band All Sky Survey (C-BASS) North telescope at Owens Valley, California, which observed from late 2012 to April 2015. Solar flux variations at 6 cm are investigated and solar data for the CBASS-N observation period are obtained from United States Air Force archives. This archived data is cleaned and used to scale the solar model used in C-BASS maps, in an attempt to improve sidelobe mapping. Although beam maps with flux scaling applied have so far not shown an improvement, the solar flux data will be used when correcting for sidelobes in C-BASS time-ordered data. Galactic loops in CBASS-N data are identified and analysed in total inten- sity and polarised intensity, with spectral index values consistent with previous findings. Little to no variation is found between the temperature spectral in- dices of Galactic loops and that of the surrounding diffuse synchrotron radiation. C-BASS temperature data confirms the existence of the hard spectrum haze re- gion, although this is not visible in C-BASS polarisation data. Four candidates for new Galactic loops from C-BASS polarisation data are proposed, with two candidates having the expected effect on polarisation angle and all candidates displaying spectral index values consistent with expected values for synchrotron emission.


Original languageEnglish
Awarding Institution
Award date1 Aug 2017