The Astrophysical Institute (ApI) presents, Karen Leighly of the University of Oklahoma Department of Physics & Astronomy, presenting “What’s in the Wind? Spectral Synthesis Modeling of Broad Absorption Line Quasars” on Wednesday, Oct. 3 at at 4:10 p.m. in Finlay Conference Room Edwards Accelerator Lab. Dr Leighly is an expert on quasars and the use of innovative methods for the analysis of their spectra. Her interests include machine learning, which is the topic of a graduate course she developed at Oklahoma.
Karen Leighly
Abstract: A significant fraction of quasars exhibit blueshifted broad absorption lines (BALs) in their rest-UV spectra, indicating powerful outflows emerging from the central engine. Despite years of study, the physical conditions of the outflowing gas are poorly understood. Our group has developed SimBAL, a novel spectral synthesis fitting method for BAL quasars that uses Bayesian model calibration to compare synthetic to observed spectra. I will describe the construction of SimBAL, and illustrate its unique strengths by discussing the results from several projects. The analysis of a HST spectrum of the low redshift broad absorption line quasar SDSS J0850+4544 reveals considerable structure as a function of velocity across the trough, including a high column density feature and a decrease in covering fraction with outflow velocity. Analysis of a sample of FeLoBALs finds a four dex range of distance from the central engine. Implications for the contribution of BALQSOs to black hole – galaxy feedback and future prospects will be briefly discussed.
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