|Galaxy Tricolor Images - 100" DuPont
Telescope, Las Campanas Observatory
Barry, Olga, Bryan and Ryan
These images were taken by Barry Madore and Olga Peranova at the Las
The data were reduced by Olga and Ryan Quadri, who is working with Dr. Bryan Penprase at Pomona College on his Harvey Mudd College senior thesis.
The reduction process includes flat fielding and flux calibration in IRAF, cosmic ray removal and continuum substraction in IDL, and a final tricolor image
was created for each of the three galaxies NGC 1313, NGC 300 and NGC 7793 based on the flux calibrated images. Each image name includes the band which
was used in the RGB images in the order of the R, G, and B channel.
The goal is to determine the inner structure of the galaxies, using
the nebular diagnostics of the lines of H-alpha, H-beta, OIII (502; 437
and 497), SII (674) and
OII (374). The line ratios of H-alpha/H-beta are sensitive to the extinction within the galaxy, OIII(502)/OIII(437) is sensitive to the temperature of the region,
SII(674)/H-alpha traces supernova shock waves, OIII(502)/H-beta is sensitive to the excitation within the nebulae, and
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