Diffuse ionized regions in the vicinity of active galaxies

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Using a sample of 39 Active Galactic Nuclei (AGN), we investigated the incidence of giant ionized clouds in the vicinity of active galaxies. We carried out remote observations of the sample using the Southeastern Association for Research in Astronomy (SARA) North telescope at Kitt Peak and the SARA South telescope on Cerro Tololo. Frames were taken in continuum V and using a narrowband filter that transmits the redshifted [O III] 5007 Å line. We formed an emission line image by subtracting the combined and scaled V frames from the combined [O III] frames. To reduce uncorrelated noise, the emission line images are median filtered with a 1".9 x 1".9 box size. To bring out large diffuse regions, we convolve the emission line image with a circular Gaussian function of 3".42 FWHM. Emergent structures are determined to be starlight or ionized gas. 21 members of our sample were recently shown to be tidally disrupted in an atomic Hydrogen (HI) study. No extended [O III]-line emission clouds were seen in the vicinity of any from this group. We found one new instance of extended ionized emission clouds near the Seyfert 1 galaxy RX J1103.2-0654.

Electronic Thesis or Dissertation