We use the EPS technique to study galaxy evolution. It involves nearly every piece of information in astronomy:
initial mass function, stellar evolution, mass loss, spectral synthesis, extinction, colour calibration, and cosmology,
to name only a few. Prof. Yi has developed his own code during his PhD years at Yale. The strengths of this models
are (1) they are based on the most up-to-date stellar models, (2) they are calibrated for mass loss using globular
cluster data, and (3) they are based on a realistic synthesis horizontal-branch models. Our current research projects
in this area include (1) the UV spectral evolution of Elliptical Galaxies, (2) the age estimation of high redshift galaxies,
and (3) the formation of elliptical galaxies through a globular cluster study.
1. The Origin of the UV Upturn in Elliptical Galaxies
2. Spectrochronology of High-Redshift Galaxies
3. Galaxy Formation via Globular Clusters
- Yi et al. 1995, ApJ, 453, L69:"Observational Tests for Ultraviolet Sources in Elliptical Galaxies:
- Yi, S. 1996, Ph.D. Thesis, Yale University
or Abstract only
- Yi, Demarque, & Kim 1997, ApJ, 482, 677:"On the UV Bright Phase of Metal-Rich HB Stars"
- Yi, Demarque, & Oemler 1997, ApJ, vol 486, 201:"On the Origin of the UV Upturn in Elliptical Galaxies. I. Sensitivity of UV Population Synthesis to Various Input Parameters"
- Yi 1997, "The Impact of the UV Upturn on the
Optical Color Evolution of E Galaxies" in The Ultraviolet
Universe at Low and High Redshift, eds. W. H. Waller, M. N. Fanelli,
J. E. Hollis, & A. C. Danks (New York: AIP Press)
- Yi, Demarque, & Oemler 1998, ApJ, 492, 480:"On the Origin of the UV Upturn in Elliptical Galaxies. II. Test of the HB Hypothesis"
- Yi, Lee, Woo, Park, Demarque, & Oemler 1999, ApJ, 513, 128:"The UV Upturn in Elliptical Galaxies as an Age Indicator"