NOAO >   Observing Info >   Approved Programs >   2014B-0169

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Proposal Information for 2014B-0169


PI: William C. Keel, University of Alabama, wkeel@ua.edu
Address: Physics Department, Box 870324, Tuscaloosa, AL 35487, USA

CoI: Matthew Bershady, University of Wisconsin
CoI: Vardha Bennert, Cal Poly San Luis Obispo
CoI: Kevin Schawinski, ETH Zurich
CoI: Chris Lintott, University of Oxford
CoI: C. Megan Urry, Yale University

Title: Giant Ionized Clouds and Fading AGN

Abstract: The Galaxy Zoo project has found high-ionization gas 10-40 kpc from the nuclei of 19 local Seyfert galaxies, with 6 new candidates. In 8 of these, the observed bolometric output of the nucleus falls far short of that needed to ionize the extended gas, suggesting rapid fading of the AGN's radiation over timescales up to 100,000 years. We propose Hexpak spectroscopic mapping of these objects. We learn not only velocity fields, but ionization structure via line ratios, a step that Hexpak is ideally designed for with its high surface-brightness sensitivity in the outer fibers. This can provide, if the geometry is favorable, a time history of the fading AGN on otherwise inaccessible spans. These AGN are preferentially associated with nuclear outflows, making them of special interest in probing AGN feedback; these data address the ionization and velocity structure across a wide range of radii. From the results, we can begin to estimate the energy in outflows, showing whether the fading of the AGN is associated more correctly with switching nodes of accretion output.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2014B-0169

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