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Paper: Activity in the Extended 12 Micron Galaxy Sample
Volume: 31, Relationships Between Active Galactic Nuclei and Starburst Galaxies
Page: 21
Authors: Rush, Brian; Malkan, Matthew A.
Abstract: We have used the IRAS Faint Source Catalog, version 2, to extend the 12-micron selected galaxy sample of Spinoglio and Malkan (1989) down to a flux limit of 0.2 Jy. Our new sample is complete all the way down to this fainter limit, giving virtually twice the number of galaxies, for a total of 798 (over all the sky with |b| > 25). Of these, 136 are already known active galaxies, and our spectroscopy is turning up several new ones. The numbers of Seyfert 1s, Seyfert 2s, LINERs, and BL Lac objects are 48, 53, 34, and 1, respectively. As anticipated, 12-micron selection is an efficient way to construct an unbiased (complete) sample of AGN, and the remaining "normal" galaxies tend to have unusually high rates of star formation - making the sample ideal for studying the connection between starburst and nuclear "activity." Since the mean redshift is low (cz = 3800 km/s), the galaxies are bright, and most have known redshifts. With CCD spectroscopy from Lick Observatory, we have nearly finished the redshift measurements. 12-micron, 60-micron, and far-IR luminosity functions have been derived. Our 60$\mu$m luminosity function for the entire sample is shown to be very similar to that of the IRAS bright galaxy sample (Soifer et al. 1987). Special attention is also being paid to the numerous interacting systems.
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