Elizabeth S. Klimek

I am currently working on my dissertation project, which uses cosmological simulations to study the relationship between processes in the disk and in the surrounding circumgalactic medium (CGM) of high redshift (2<z<4) galaxies. This redshift range is interesting because it is the time period leading up to the most active period of star formation in galaxies.

Understanding the cycle of baryons during this time is important for understanding galaxy formation and evolution. Gas accretion from the intergalactic medium (IGM) must pass through and interact with the multiphase circumgalactic medium (CGM), which makes up the gaseous halo component of a galaxy. The CGM itself can also serve as a reservoir of gas that could eventually cool and accrete onto the disk. Stellar feedback due to star formation drives winds that carry metals away from the disk and into the halo. If the wind speeds exceed the escape velocity of the galaxy, the outflowing gas will enrich the the IGM. However, if the wind speeds are below the escape speed, the outflowing material could either linger in the halo or rain back down onto the disk in a fountain type flow. The fate of the outflow gas thus has consequences for the evolution of the disk.

My first introduction to astronomy research came when I got involved in AGN variablility research under the guidance of Martin Gaskell at the University of Nebraska-Lincoln as an undergraduate. I then went on to do a masters thesis project on the optical variability of Narrow-Line Seyfert 1 Galaxies.

Narrow-Line Seyfert 1 (NLS1) galaxies are active galaxies that exhibit large amplitude, rapid (sub-diurnal, or on the timescale of hours) variability in the X-rays. Curiously, I did not detect any such rapid variability in the optical part of the spectrum for my sample of six NLS1s. Since there is no connection or correlation between the X-ray and the optical behavior, there must be a different production mechanism accounting for each of the continuum bands.