Other
Scientific paper
Dec 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992phdt.........8w&link_type=abstract
Ph.D. Thesis California Univ., Santa Cruz.
Other
85
Color-Color Diagram, Elliptical Galaxies, Mathematical Models, Metallic Stars, Stellar Color, Stellar Evolution, Absorption Spectra, Age Factor, Metallicity, Stellar Luminosity, Stellar Temperature
Scientific paper
Stellar evolutionary isochrones are coupled with mostly theoretical flux distributions of stars in order to predict the flux distributions and colors of stellar populations as a function of population age and metallicity. Twenty one empirical indices of absorption feature strengths are measured for ensembles of stars of differing ages, temperatures, and metallicities. These indices are expressed as polynomials in stellar temperature, surface gravity, and metallicity, and are applied to the population models to predict index strengths as a function of population age and metallicity. Checks are made against stellar observations. The model predictions are compared to measured indices of elliptical galaxies. The logarithmic ratio (Mg/Fe) (which is zero for a scaled solar ratio) is shown to be greater than that of the most metal-rich stars in the solar neighborhood in giant elliptical galaxies. Since (Mg/Fe) is probably near zero for metal-rich stars, (Mg/Fe) appears to be greater than zero in giant ellipticals, but not in smaller, M32-class, ellipticals. This behavior is probably mirrored in Na and CN indices, suggesting that all light elements are relatively enhanced in giant ellipticals, on average. The nucleosynthetic history of giant ellipticals must differ from that of smaller ellipticals. Surface brightness fluctuation magnitudes are predicted. Models agree with the empirical I-band calibration, giving extragalactic distances which may be good to 10 percent for galaxies well-measured in two passbands. Qualitative agreement is also reached in fluctuation color-color diagrams and color-index diagrams. A fluctuation magnitude which is independent of color probably exists between Cousins I and Johnson J. The model results are tabulated. The sensitivity of all model predictions with age and metallicity are explored. H(Beta) and the G band provide the best age sensitivity of any color or index yet studied; Fe features are the most metallicity sensitive in the absence of abundance ratio differences. A factor of three change in age produces the same change in most colors and indices as a factor of two in Z. The effects of Z, age, and abundance ratio differences most profoundly affect the integrated light of stellar population. Other parameters have effects comparable to the model uncertainties.
No associations
LandOfFree
The controlling parameters of the integrated flux of a stellar population does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The controlling parameters of the integrated flux of a stellar population, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The controlling parameters of the integrated flux of a stellar population will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1140951