10 μ m imaging and HI observations of the Blue Compact Dwarf Galaxy He 2 - 10 ⋆

We have observed the Blue Compact Dwarf (BCD) galaxy He 2-10 in the ∼10 µm mid-infrared (MIR) atmospheric window using broad-band filters centered at λ10.1 µm and λ11.65 µm. In both filters, only the galaxy's central regions were detected. One of the UV emitting regions is not detected, implying an older age. The central region contain two resolved components which have the same MIR properties but different Hα fluxes. We interpret these properties in terms of differing star forming histories. Based on its morphology, we show that the MIR emission is unambiguously associated with the young massive stars. We study the spatial variations of the MIR color and conclude that they imply the existence of a hot grain contribution to the 11.65 µm flux in the central regions of the starburst. We also present a new single-dish measurement of the Hi content of He 2–10.