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Full-Text Articles in Astrophysics and Astronomy
Individual Element Sensitivity For Stellar Evolutionary Isochrones, Guy Worthey, Xiang Shi, Tathagata Pal, Hyun-Chul Lee, Baitian Tang
Individual Element Sensitivity For Stellar Evolutionary Isochrones, Guy Worthey, Xiang Shi, Tathagata Pal, Hyun-Chul Lee, Baitian Tang
Physics and Astronomy Faculty Publications and Presentations
Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. The individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect relevant to integrated light models is contained in the temperature variable, as opposed to the time-scale or luminosity. We derive a recipe for including abundance-sensitive temperature effects that is applicable to existing isochrone grids. The resultant enhanced isochrones are incorporated into composite stellar population models and compared with galaxy data from the Sloan Digital Sky Survey. A severe oxygen–age degeneracy is apparent, 2–3 …
The Properties Of The Stellar Nuclei With The Host Galaxy Morphology In The Acsvcs, Hyun-Chul Lee
The Properties Of The Stellar Nuclei With The Host Galaxy Morphology In The Acsvcs, Hyun-Chul Lee
Physics and Astronomy Faculty Publications and Presentations
We have revisited the ACS Virgo Cluster Survey (ACSVCS), a Hubble Space Telescope program to obtain ACS/WFC g and z bands imaging for a sample of 100 early-type galaxies in the Virgo Cluster. In this study, we examine 51 nucleated early-type galaxies in the ACSVCS in order to look into the relationship between the photometric and structural properties of stellar nuclei and their host galaxies. We morphologically dissect galaxies into five classes. We note that (1) the stellar nuclei of dwarf early-type galaxies (dS0, dE, and dE,N) are generally fainter and bluer with g > 18.95 and (g-z) < 1.40 compared to some brighter and redder counterparts of the ellipticals (E) and lenticular galaxies (S0), (2) the g-band half-light radii of stellar nuclei of all dwarf early-type galaxies (dS0, dE, and dE,N) are smaller than 20 pc and their average is about 4 pc, and (3) the colors of red stellar nuclei with (g - z) > 1.40 in bright …