10 microns imaging and HI observations of the Blue Compact Dwarf Galaxy He 2-10

Abstract

We have observed the Blue Compact Dwarf (BCD) galaxy He 2-10 in the 10 microns mid-infrared (MIR) atmospheric window using broad-band filters centered at lambda=10.1 microns and lambda=11.65 microns. 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 contains two resolved components which have the same MIR properties but different Halpha 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 microns flux in the central regions of the starburst. We also present a new single-dish measurement of the HI content of He 2-10.