Outflow and Accretion PHysics

My dissertation involves studying the physics of gas outflows and accretion of matter in Active Galactic Nuclei (AGN).  The primary goal is to better understand the physical conditions of AGN outflows and how various forms of accretion onto supermass
ive black holes regulate those conditions.

Understanding outflows in relation to accretion in AGN has broad implications in current astronomical research.  Outflowing gas may inject a significant amount of energy and momentum into the interstellar medium, thereby regulating star formation in the host galaxy.  Supermassive black holes also appear linked with certain host galaxy properties, and their growth over cosmic time is likely regulated by accretion flows.  The connections between AGN and host galaxy evolution requires detailed analyses of outflow and accretion properties. 





Investigation of outflows is carried out by studying how spectral absorption lines, the signatures of outflowing gas, change over time.  Absorption line variability allows us to place physical constraints on outflows such as location, density, and kinetic energy.  A large portion of my thesis focuses on constraining various types of outflows to shed light on their formation/acceleration mechanisms and the shared properties between them.

One way to probe various accretion flow models in AGN is to directly measure the supermassive black hole mass at the center of a galaxy.  We accomplish this by utilizing the kinematics of the gas in the vicinity of the black hole.  Estimating a black hole mass in a galaxy of interest will allow us to investigate and constrain the structure and parameters of the accretion flow.

My research has utilized spectra acquired from the following observatories:



Example Spectrum

MDM Hiltner Telescope

Sloan Digital Sky Survey

Hubble Space Telescope

Hobby Eberly Telescope