ULTRAVIOLET SPECTROSCOPY OF CIRCUMNUCLEAR STAR CLUSTERS IN M83
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
- University of Toledo, Department of Physics and Astronomy, Toledo, OH 43606 (United States)
We analyze archival HST/STIS/FUV-MAMA imaging and spectroscopy of 13 compact star clusters within the circumnuclear starburst region of M83, the closest such example. We compare the observed spectra with semi-empirical models, which are based on an empirical library of Galactic O and B stars observed with IUE, and with theoretical models, which are based on a new theoretical UV library of hot massive stars computed with WM-Basic. The models were generated with Starburst99 for metallicities of Z = 0.020 and Z = 0.040, and for stellar initial mass functions (IMFs) with upper mass limits of 10, 30, 50, and 100 M{sub sun}. We estimate the ages and masses of the clusters from the best-fit model spectra and find that the ages derived from the semi-empirical and theoretical models agree within a factor of 1.2 on average. A comparison of the spectroscopic age estimates with values derived from HST/WFC3/UVIS multi-band photometry shows a similar level of agreement for all but one cluster. The clusters have a range of ages from about 3 to 20 Myr and do not appear to have an age gradient along M83's starburst. Clusters with strong P-Cygni profiles have masses of a fewx10{sup 4} M{sub sun}, seem to have formed stars more massive than 30 M{sub sun}, and are consistent with a Kroupa IMF from 0.1to100 M{sub sun}. Field regions in the starburst lack P-Cygni profiles and are dominated by B stars.
- OSTI ID:
- 21567540
- Journal Information:
- Astrophysical Journal, Vol. 727, Issue 2; Other Information: DOI: 10.1088/0004-637X/727/2/100; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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