My thesis investigates the connections between star formation feedback and gas kinematics over a range of physical and star formation rate scales. My thesis advisor is Prof. Alberto Bolatto.
The first chapter of my thesis is related to the kinematics of extraplanar diffuse ionized gas (eDIG) in nearby, normally star-forming galaxies from the EDGE and CALIFA surveys. In my first paper, I derive molecular and ionized gas rotation curves for a sample of intermediate inclination galaxies. I find that the ionized gas rotates systematically slower than the molecular gas in the majority of these systems. We attribute this difference in rotation velocity to the presence of eDIG, which rotates more slowly with increasing height above the galaxy midplane. Viewed at an intermediate inclination, this effect leads to the systematically lower ionzied gas rotation velocities.
In order to measure eDIG properties directly, my second paper analyzes the ionized gas scale height, vertical gradient in the rotation velocity, and ionization properties of eDIG in a sample of edge-on CALIFA galaxies. We again find evidence for eDIG in the majority of galaxies studied, indicating the pervasive nature of this phase in nearby star-forming galaxies. This WIM-like phase is an important component to these galaxies, and the ionization of the eDIG is consistent with ionization from star formation activity in the midplane. Therefore, star formation feedback plays a role even in normally star-forming galaxies.
The second chapter of my thesis focuses on super star clusters (SSCs) in the central starburst of NGC253. High resolution ALMA data reveal dusty, compact, massive stellar clusters potentially powering the starburst-driven outflow (Leroy et al. 2018). Using even higher resolution ALMA data (30 mas = 0.5 pc), we find evidence for outflows from some of these SSCs. My third paper will focus on the properties of these outflows (such as the outflow velocity, mass, and energy injection) as well as modeling to constrain the outflow opening angles and inclinations. My fourth paper will study the continuum properties of these SSCs to constrain the cluster mass function.
In the final chapter of my thesis, I will study the kinematics of the galaxy-scale outflow in the prototypical starbust galaxy M82. I am the PI of cycle 7 SOFIA observations of the [CII]158μm line in the disk and outflow of M82. These spatially- and velocity-resolved measurements will allow for [CII] to be measured in the outflow of M82 for the first time. It is expected that the outflow should transition from molecular to atomic gas, and these data will probe this transition region. Moreover, the atomic gas in the outflow decelerates (Martini et al. 2018) whereas there is no such deceleration seen in the molecular gas (Leroy et al. 2015). These velocity resolved [CII] measurements (which are only possible with upGREAT on SOFIA) will determine whether the [CII] decelerates or not.