My current research pertains to the low redshift Lyman-alpha forest and how feedback from galaxies might affect the structure and thermal state of the intergalactic medium (IGM). I generate mock Lyman-alpha spectra from cosmological simulations from which I extract summary statistics for the forest. At low redshift (z = 2 and less), the Lyman-alpha forest is difficult to observe due to the need for space based telescopes that collect data in the far-ultraviolet wavelength band. From the data we have been able to collect, a distinct disconnect between observed data and simulations implies a gap in our understanding of the physical mechanisms that drive structure formation and heating in the IGM. I am exploring the potential role of supermassive black hole (SMBH) feedback in resolving the disconnect between simulations and observations through the study of different SMBH feedback sub-grid models in simulations. (The image on the left includes temperature and column density projections of the CAMELS-Simba simulations with varying feedback parameters from Tillman et al. 2023.)

From my work, we have determined that SMBH jet feedback in particular can play a large role in redefining the thermal state and physical distribution of the IGM. The effects of these jets can even be distinguishable from effects of the ultraviolet background which traditionally has been used to try and reproduce the observed Lyman-alpha forest in simulations. When exploring the Lyman-alpha column density distribution (CDD), our results have implied that SMBH jet feedback may play a vital role in reproducing the observed forest in simulations. While the CDD has been more accurately reproduced by multiple studies in the past few years, the b-value distribution is another story. The b-value of an absorber contains information about the motion of that absorber due to temperature, gravitational influences, and turbulence. No simulation has been able to reproduce a b-value distribution that matches observational data to an acceptable degree. Whether this is due to a lack of heating, missing turbulence, or even a lack of physical mechanisms that are not even simulated at the moment, such as cosmic rays, is unclear. The mismatched statistic is likely due to a number of factors but this problem is one I plan to explore further in my future work.

Beyond the Lyman-alpha forest I am also interest in: galaxy formation and evolution, co-evolution of galaxies and their central SMBHs, SMBH formation and growth, the interplay between SMBH and stellar feedback, and the construction of new SMBH feedback sub-grid models.