NOAO >   Observing Info >   Approved Programs >   2011A-0247

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Proposal Information for 2011A-0247


PI: Karen M. Leighly, University of Oklahoma, leighly@nhn.ou.edu
Address: Homer L. Dodge Department of Physics and Astronomy, 440 W. Brooks St., Norman, OK 73019, USA

CoI: Donald Terndrup, National Science Foundation
CoI: Matthias Dietrich, Ohio State University
CoI: Sarah Gallagher, University of Western Ontario
CoI: Sara Barber, University of Oklahoma

Title: Metastable HeI Absorption: The First Systematic Study of Column Density and Covering Fraction in BALQSOs

Abstract: Outflows are an essential part of quasars, but their physical properties still pose significant puzzles. Some observational parameters, such as the maximum outflow velocity and the velocity width, are well studied and yield clues about the acceleration mechanism and viewing angle. Other parameters, including column density and covering fraction, are much less well understood. Yet these parameters are essential for understanding quasar outflows and constraining their physical properties. Our recent discovery of blue-shifted broad absorption from HeI*(lambda) 10830 in spectra of several quasars, and our analysis along with HeI*(lambda) 3889, led us to realize that these two lines are supremely suitable for measuring the column density and covering fraction. We propose observations of HeI*(lambda) 3889 in a carefully- chosen sample of quasars for which we anticipate obtaining HeI*(lambda) 10830 measurements. These observations offer the \it first opportunity to systematically study the relationship between the column density and the covering fraction and the better-studied maximum velocity and velocity width. We anticipate the results will constrain both the kinetic energy and geometry of the outflow.


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NOAO >   Observing Info >   Approved Programs >   2011A-0247

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