Ivanna Escala

I am a Carnegie-Princeton Fellow at the Carnegie Observatories in Pasadena, CA.

Previously, I obtained my PhD from the California Institute of Technology and completed my undergraduate studies at the University of California, San Diego.

I use large ground-based telescopes to measure chemical abundances of individual stars in nearby galaxies to learn about galaxy formation history. In particular, I am interested in the relationship between galaxy accretion history and the formation of stellar disks and halos, and more broadly, galaxy formation in the Local Group and Local Volume. I am also interested in making connections between observations and models of galaxy evolution.

Media

See below for some links to public talks, interviews, and articles.

• Caltech Letters article
• Astronomy on Tap, Trenton
• Interview with Astronomy in Color
• Caltech Astro public talk

Research

See below for a short summary of ongoing and past projects.

Elemental Abundances in M31

My collaborators and I have undertaken the largest deep (5+ hr) spectroscopic survey of M31 to date using the DEIMOS instrument on Keck. We have made the first measurements of [Fe/H] and [α/Fe] for individual red giants in the inner stellar halo and the stellar disk, and have substantially increased the number of available chemical abundance measurements in the outer halo and M31's dwarf galaxies. See Escala+19,20a,20b,21, Gilbert+19,20, Kirby+20, and Wojno+20 for our key results.

Low-Resolution Resolved Stellar Spectroscopy

In order to make chemical abundance measurements for individual stars in relatively distant galaxies like M31, I developed a technique to apply spectral synthesis to low-resolution spectroscopy (Escala+19). By moving to lower spectral resolution, we maximize the signal-to-noise per spectral resolution element, such that we can measure [Fe/H] and [α/Fe]. I am currently working on modifying this method to work with Magellan/IMACS to probe distant galaxies in the Southern Hemisphere.

Subaru Prime Focus Spectrograph

I am part of the Subaru/PFS Galactic Archaeology team. PFS is an optical and near-infrared multi-fiber spectrograph that will be capable of obtaining low- and moderate resolution spectra for thousands of targets simultaneously. I am currently developing the GA 1D chemical abundance pipeline, and I will be leading the chemical abundance analysis of the M31 subsurvey. (Image credit Masashi Chiba)

Modeling Chemical Abundance Distributions

I have used cosmological, hydrodynamics simulations of dwarf galaxies from the Feedback in Realistic Environments (FIRE) project to investigate the impact of a sub-grid metal mixing prescription for the turbulent diffusion of metals in gas on chemical abundance distributions (Escala+18). Including extra metal mixing in Lagrangian simulations is important for producing realistic abundance distrbutions for Local-Group-like dwarf galaxies.