NOAO >   Observing Info >   Approved Programs >   2014A-0532

Small NOAO Logo

Proposal Information for 2014A-0532


PI: Patrick Hall, York University, yorkphall@gmail.com
Address: Department of Physics and Astronomy, 4700 Keele Street, North York, ON M3J 1P3, Canada

CoI: Paola Rodriguez Hidalgo, York University
CoI: W. Niel Brandt, Pennsylvania State University
CoI: Jesse Rogerson, York University
CoI: Nur Filiz Ak, Pennsylvania State University
CoI: Laura Chajet, York University

Title: Monitoring Emergent Absorption Troughs in Quasars

Abstract: Outflows from luminous AGN are important ingredients in galaxy formation. These outflows manifest as broad absorption line (BAL) troughs in quasar spectra. Trough variability can be used to constrain the physical parameters of these absorbing structures through comparison to models and simulations of accretion disk winds. Monitoring appearing/disappearing BAL troughs can constrain the distribution of BAL trough lifetimes along our line of sight. By comparing spectra from the SDSS Data Release (DR) 7 and DR 9, we identified 68 quasars in whose spectra new absorption troughs have appeared over 300-1200 restframe days, including one trough outflowing at v=60,000 km/s. We propose to complete our third-epoch GMOS spectroscopy of the brightest of those quasars (48 in 2013AB and 9 proposed here) to measure the absorption strength in newly appeared troughs <=365 restframe days after their previous measurement. Preliminary 2013AB results indicate that troughs are not on average still strengthening between SDSS and Gemini epochs; we therefore propose observations of 40 targets to probe shorter rest-frame time separations. We also target 8 objects showing simultaneous absorption variations in multiple ionization states, to help develop methods to distinguish absorption variations from cloud motion vs. those from ionization changes within clouds.


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 >   2014A-0532

noaoprop-help@noao.edu

Small NOAO Logo