- Startpagina tijdschrift
- Volume 80 - Année 2011
- FUV and UVIS observations of circumnuclear star clusters in M83
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FUV and UVIS observations of circumnuclear star clusters in M83
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Abstract
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 IMFs with upper mass limits of 10, 30, 50, and 100Mo. 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 2 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 few ×104Mo, seem to have formed stars more massive than 30Mo, and are consistent with a Kroupa IMF from 0.1-100Mo.
Om dit artikel te citeren:
Over : Aida Wofford
Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
Over : Rupali Chandar
University of Toledo, Department of Physics and Astronomy, Toledo, OH 43606, USA
Over : Claus Leitherer
Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA