NOAO >   Observing Info >   Approved Programs >   2002A-0119

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Proposal Information for 2002A-0119


PI: Armando Gil de Paz, Infrared Processing and Analysis Center, agpaz@ipac.caltech.edu
Address: 770 S. Wilson Ave. / Mail Code 100-22, Pasadena, CA 91125

CoI: Barry F. Madore, IPAC & OCIW

Title: Star formation properties of nearby galaxies: NIR imaging of the UIT sample

Abstract: We intend to obtain J and K near-infrared imaging (FLAMINGOS+KPNO2.1m) for a sample of 12 nearby late-type spiral and irregular galaxies observed by the Ultraviolet Imaging Telescope. In addition to the UIT far-UV images, we have already obtained optical UBVRI images for the whole sample. Using these observations and the near-infrared images here requested we will determine the SEDs between 1500-22000 Afor all the star clusters and associations detected in our far-UV images. The SEDs obtained will be compared with the predictions of evolutionary synthesis models adopting different dust-to-star geometries and extinction laws. Using a new, powerful comparison procedure we will be able to determine the properties of these star clusters (IMF, SFR, age, E(B-V), metallicity) along with the corresponding errors and degeneracies between the properties derived. Further comparison of these properties with the H(alpha) and UV luminosities and H(alpha)/H(beta) line ratios measured (H(alpha) imaging already obtained; H(beta) in progress) will allow us: (1) to empirically determine the relation between the stellar and gas dust attenuation, (2) to estimate the fraction of Lyman photons that are being absorbed by dust (or escaping) before the ionization of the surrounding gas, and ultimately, (3) to calibrate the H(alpha) and UV luminosities as indicators of the SFR in galaxies.


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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