9 papers · 1 filter
The New Standard Stellar Population Models (NSSPM) -- The Prologue
Hyun-chul Lee, Guy Worthey, Scott C. Trager +7
We are developing a brand new stellar population models with flexible chemistry (isochrones plus stellar colors and spectra) in order to set a new standard of completeness and exce…
The Effect Of Alpha-Element Enhancement On Surface Brightness Fluctuation Magnitudes And Broad-Band Colors
Hyun-chul Lee, Guy Worthey, John P. Blakeslee
We present the effects due to alpha-element enhancement on surface brightness fluctuation magnitudes and broad-band colors in order to investigate the calibration zero-point. We st…
On the Age and Metallicity Estimation of Spiral Galaxies Using Optical and Near-Infrared Photometry
Hyun-chul Lee, Guy Worthey, Scott C. Trager +1
In integrated-light, some color-color diagrams that use optical and near-infrared photometry show surprisingly orthogonal grids as age and metallicity are varied, and they are comi…
A New delta N Formalism for Multi-Component Inflation
Hyun-Chul Lee, Misao Sasaki, Ewan D. Stewart +2
The delta N formula that relates the final curvature perturbation on comoving slices to the inflaton perturbation on flat slices after horizon crossing is a powerful and intuitive…
From the Spectrum to Inflation : An Inverse Formula for the General Slow-Roll Spectrum
Minu Joy, Ewan D. Stewart, Jinn-Ouk Gong +1
We propose a general inverse formula for extracting inflationary parameters from the observed power spectrum of cosmological perturbations. Under the general slow-roll scheme, whic…
Is the Initial Mass Function of Low Surface Brightness Galaxies Dominated by Low Mass Stars?
Hyun-chul Lee, Brad K. Gibson, Chris Flynn +2
The rotation curves of low surface brightness (LSB) galaxies suggest that they possess significantly higher mass-to-light (M/L) ratios than their high surface brightness counterpar…