Links

Contact

Email: ie{at}astro{dot}caltech{dot}edu

Office: 256 Cahill

Mail:
Caltech
1200 E California Blvd
Pasadena, CA 91125
MC 249-17

Phone: (626)-395-6857

Research

(Figures from Escala et al., 2017, submitted. arXiv:1710.06533 )

As a junior graduate student at Caltech, I investigated the stellar metallicity distribution functions (MDFs), including iron and alpha element abundances, in dwarf galaxies from the Feedback in Realistic Environments (FIRE) project. I examined both isolated dwarf galaxies and those that are satellites of a Milky Way mass galaxy. In particular, I studied the effects of a sub-grid turbulent model for the diffusion of metals in gas. Compared to simulations without diffusion, we observe a narrowing of both the metallicity distribution function (left) and abundance ratio distributions, which results from individual particles being driven toward the average metallicity. This effect results in better agreement with observations of Local Group dwarf galaxies (right), e.g., in terms of the metallicity distribution function shape and width. We also find agreement between the small intrinsic scatter in the alpha-to-iron ratio in simulations and observations of dwarf galaxies. This implies that the interstellar medium in dwarf galaxies is well-mixed at nearly all cosmic times. Lastly, via comparison between isolated and satellite dwarf galaxies, I found that the similarly between their chemical abundance distributions suggests that environmental effects play a minor role compared to internal chemical evolution in the FIRE simulations.