The Decomposition and Analysis of the NGC720 Galaxy

Benjamin Jenkins


In this thesis the relationship between galaxy morphology and the surrounding halo shape is examined. This analysis focused on the nearby elliptical galaxy, NGC720, whose images were acquired through the HERON survey study. By examining the photometry of the galaxy and creating surface brightness profiles of the galaxy and nearby objects, the light model’s accuracy was examined. Using the program GALFIT, the light of the developed model was subtracted from the light of the original image, leaving a residual image to be studied. A good fitting model left only the background sky, whereas any model too bright or too dim left dark and light spots/areas. The NGC720 galaxy received a single and multiple component modeling of the surface brightness profile. The single component model treated the galaxy as a single object whereas the multiple component model allowed for different areas and sections of the galaxy to be modeled separately. While the resulting residual images showed that the multiple component modeling provided a superior fit of the galaxy, neither was effective in establishing any trend or correlation between the NGC720 galaxy and its halo. Further research should skip the single component model and focus on creating a multiple component model where the halo of the galaxy can be isolated. Several other galaxies should also be examined to see if any correlations can be seen.