Summer Seminar: Shirley Li and Kelly Denney

November 14, 2016
Tuesday, July 26, 2016 - 11:30am to 12:30pm
4138 PRB
Oval

"Observing Neutron Stars"

Shirley Li (Physics)

Neutron stars are interesting objects both for astronomers and for nuclear physicists. They are abundant in our galaxy, yet we have only observed a tiny fraction of their population. In my talk, I will discuss a new approach to surveying neutron stars. Our preliminary results show that the current generation telescope may have sensitivity to detect neutron stars.

 

"On the Reliability of CIV-based Black Hole Masses: We're Making Progress"

Kelly Denney (Astronomy)

Being able to reliably determine quasar black hole masses based on the rest-UV CIV emission line has benefits for understanding black hole growth and galaxy evolution in the early universe because this line redshifts into the more easily-accessible visible wavelength regime for z >~ 1.5. However, there has been an unresolved and continuing controversy attached to using CIV as a virial mass indicator due to apparent inconsistencies between masses based on this line and the more robustly-tested Hbeta emission line. I will discuss how these inconsistencies largely appear to be due to the lack of understanding of the origin and object diversity in the CIV emission components, how this is connected to the geometry and kinematics of the variable broad line region, and how this in turn affects our ability to use simple line width characterizations as a proxy for the velocity dispersion of the variable CIV-emitting BLR gas. I will then present selected results of several recent projects that have been aimed to improve our understanding of CIV emission as a means to improve the reliability of this emission line as a virial black hole mass indicator.

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