Dr. Petia Yanchulova Merica-Jones

I am a postdoctoral researcher in the ISM*@ST group at the Space Telescope Science Institute.
I work with Dr. Karl Gordon and Dr. Claire Murray on the Scylla project and other surveys
using the BEAST tool to study dust and interstellar medium properties in nearby galaxies.
I received my PhD in Physics (Astrophysics) from the University of California, San Diego in 2020.

Research

The properties and evolution of the interstellar medium (ISM) of galaxies govern galaxy formation and evolution. My research has to do with understanding these properties in nearby galaxies. The Small and Large Magellanic Clouds (SMC & LMC), in particular, are excellent laboratories for observing spatially resolved stellar populations and individual gas/dust clouds enabling a detailed analysis of the ISM and stellar properties.

Dust Extinction

Color-magnitude diagrams (CMDs) of reddened stars can provide rich information about dust extinction properties of nearby galaxies. I use CMDs to study dust extinction as a way to constrain dust grain properties. My research has made use of Hubble Space Telescope observations of resolved stars in the SMC to understand how the dust extinction curve at low-metallicity may be different from that in evolved galaxies. [SMIDGE, PI K. Sandstrom]
Yanchulova M-J et al. 2017, ApJ

Galactic Geometry

Observations of spatially-resolved stellar populations make it possible to analyze the 3-D structure of the stars, dust, and gas. My thesis focused on modeling the effects of dust extinction and galactic geometry (stellar and dust layer positions and relative offsets) on the CMD of stars in the SW Bar of the SMC. We found that when CMDs are used to study dust extinction in nearby galaxies, the stellar and dust geometry must be modeled as well to properly infer the dust properties.
Yanchulova M-J et al. 2020 acc., ApJ

Dust + Stellar Properties

The wealth of information contained in photometric surveys of resolved stars in nearby galaxies - such as Scylla (PI C. Murray ) and SMIDGE - makes it possible to model the stellar and dust properties together. The BEAST tool enables high resolution mapping of stellar and dust properties by fitting the individual stellar photometry to a stellar physics model and models for the dust extinction and observational uncertainties. Additionally, the chemical enrichment and star formation histories can be studied in great detail.

Publications

Astronomy Data Service Publications Search

  • Submitted to ApJ March 2024: A Catalog of Stellar and Dust Properties for 500,000 stars in the Southwest Bar of the Small Magellanic Cloud.
  • 2021: Three-Dimensional Structure and Dust Extinction in the Small Magellanic Cloud, The Astrophysical Journal, 2021, 907:50.
  • 2017: The Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE): The Dust Extinction Curve from Red Clump Stars. The Astrophysical Journal, 2017, 847:102.