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Masters Thesis Defense

Assessing AGN Feedback Models with C III* Measurement and Photoionization Modeling

Dan McGinnis


Mass outflows in active galactic nuclei (AGN) have been hypothesized to represent a feedback mechanism through which black hole growth and galaxy formation are linked. In order to assess this claim, typical outflow kinetic luminosities must be compared to calculated minimum values that are needed to produce feedback relevance. We have developed a method for placing lower limits on the kinetic luminosity by combining photoionization modeling with column density measurements of a select few ionic species, including C III* λ1175 as a measure of gas density. This method is applied to sample AGNs representative of those observed with the Sloan Digital Sky Survey (SDSS) and the Cosmic Origins Spectrograph (HST-COS). We find that although measured kinetic luminosity lower limits for the quasar SDSS J170322.41+23124.3 and Seyfert galaxy Akn 564 are several orders of magnitude less than that required for feedback relevance, our method can be drastically improved with increased signal to noise ratios.

Date of Event: 
Friday, August 9, 2013 - 13:00
Hixson Lied G79
Contact info: 
Dr. Michael Nichols

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