Characterizing the Background Corona with SDO/AIA

Characterizing the nature of the solar coronal background would enablescientists to more accurately determine plasma parameters, and may lead to abetter understanding of the coronal heating problem. Because scientists studythe 3D structure of the Sun in 2D, any line of sight includes both foreground andbackground material, and thus, the issue of background subtraction arises. Byinvestigating the intensity values in and around an active region, using multiplewavelengths collected from the Atmospheric Imaging Assembly (AIA) on theSolar Dynamics Observatory (SDO) over an eight-hour period, this project aimsto characterize the background as smooth or structured. Different methods wereemployed to measure the true coronal background and create minimumintensity images. These were then investigated for the presence of structure.The background images created were found to contain long-lived structures,including coronal loops, that were still present in all of the wavelengths, 131,171, 193, 211, and 335 Å. The intensity profiles across the active regionindicate that the background is much more structured than previously thought.