NOAO > Observing Info > Approved Programs > 2002B-0159
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NOAO > Observing Info > Approved Programs > 2002B-0159 |
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PI: Akihiko Tomita, Wakayama University, atomita@center.wakayama-u.ac.jp
Address: Wakayama 640-8510, Japan
CoI: Deidre Hunter, Lowell Observatory
CoI: Tsutomu T. Takeuchi, Natl. Astron. Obs. Japan
CoI: Kohji Yoshikawa, Kyoto University
CoI: Hiroyuki Hirashita, Arcetri Observatory
Title: Blue Compact Dwarfs: Young-to-Old Ratio
Abstract:
Infrared imaging and color-magnitude diagram analysis show that Blue
Compact Dwarfs (BCDs), once thought to be young galaxies, contain an old
stellar population. But, how large is the contribution of the old
population? We are proposing to obtain the data necessary to determine
the relative contribution of the young (younger than 1 Gyr) and old
(older than 1 Gyr) stellar populations in a sample of BCDs. We use area-
integrated, low dispersion spectra with a wide wavelength coverage. We
have developed a spectral decomposition method to extract the relative
contribution of present and past stellar populations from these spectra.
The analysis of color-magnitude diagrams is another tool to explore the
star formation history. However, it is very difficult to measure faint
stars, which are crucial to quantitatively evaluating the amount of the
old population. The present-to-past ratio of the star formation rate
has been estimated from broad-band imaging, but that analysis must
assume a parametric star formation history. Our approach bridges these
two techniques. The young-to-old ratio is an important information to
understanding how these galaxies evolve and their relationship to faint
blue galaxies at intermediate redshifts.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2002B-0159 |
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