2003ApJ...586..939C

We use new Space Telescope Imaging Spectrograph long-slit ultraviolet spectroscopy of region A in the nearby starbursting galaxy He 2-10 to examine properties of both compact individual super-star clusters and diffuse intracluster regions. The four most luminous clusters in our slit formed coevally 4-5 Myr ago and have lower mass estimates of severalx10⁴ to a fewx10⁵M_☉. A fifth cluster is located ∼200 pc away, and appears to be several megayears older. Extracted spectra of the diffuse light appear to be remarkably similar to those of the young clusters, showing P Cygni profiles from massive stars, and are very well fitted by instantaneous burst models of 4-5 Myr. Various mechanisms are considered to determine the nature of the underlying diffuse light in He 2-10. We rule out scattering of cluster light as the dominant source of the observed field. A scenario including the formation of a large number of lower mass, undetectable but coeval (compact) clusters can explain the field spectra, assuming that the clusters in the center of region A follow a power-law luminosity distribution, L^–α, with α=-2.0. This is somewhat steeper than the power-law slope of -1.7 measured by Johnson et al. for clusters in a larger portion of He 2-10 and implies very high projected (compact) cluster densities within region A. Rather, we favor a scenario where the dominant contribution to the field stellar population comes from more diffuse ``scaled OB associations'', which are not lacking in the most massive stars. Our observations establish that the far-UV field light in He 2-10 originates in a different stellar population than found for NGC 5253 and other nearby starbursts, where older, dissolving clusters appear to be the main mechanism responsible for creating the diffuse UV light.