10 micron silicate feature in southern H II regions

Intermediate-band photometric measurements in the 10 μ region are presented for 22 infrared sources associated with southern H II regions. The energy distributions display substantial silicate absorption with optical depths at band center (9.8μ) ranging from 0.4 to 5.0. The depth of the 9.8μ band is related to the depth of 6 cm formaldehyde absorption in the sense that tau(9.8μ) must exceed 2 for tau(H2CO) to exceed 0.03. The effect of the silicate absorption is to attentuate the intrinsic 1-25μ luminosities by as much as a factor of 5