ar X iv : a st ro - p h / 00 12 08 9 v 1 5 D ec 2 00 0 Near - IR Spectroscopy and Population Synthesis of Super Star Clusters in NGC 1569
نویسنده
چکیده
We present Hand K-band NIRSPEC spectroscopy of super star clusters (SSCs) in the irregular starburst galaxy NGC 1569, obtained at the Keck Observatory. We fit these photospheric spectra to NextGen model atmospheres to obtain effective spectral types of clusters, and find that the information in both Hand K-band spectra is necessary to remove degeneracy in the fits. The light of SSC B is unambiguously dominated by K0 supergiants (Teff = 4400 ± 100 K, log g = 0.5 ± 0.5). The double cluster SSC A has higher Teff (G5) and less tightly constrained surface gravity (log g = 1.3 ± 1.3), consistent with a mixed stellar population dominated by blue Wolf-Rayet stars and red supergiants. We predict the time evolution of infrared spectra of SSCs using Starburst99 population synthesis models coupled with empirical stellar spectral libraries (at solar metallicity). The resulting model sequence allows us to assign ages of 15–18 Myr for SSC B and 18–21 Myr for SSC A.
منابع مشابه
ar X iv : a st ro - p h / 01 05 19 5 v 1 1 1 M ay 2 00 1 The stellar content of the super star clusters in NGC 1569 ⋆
We discuss HST FOS ultraviolet spectroscopy and NICMOS near-infrared photometry of four young super star clusters in the central region of the irregular starburst galaxy NGC 1569. The new observations coupled with previous HST WFPC2 photometry and ground-based optical spectroscopy allow us to isolate and age-date the hot and cool stellar components of these massive clusters. We analyze the two ...
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