H166 Studies of Extended Low-Density H II Regions Associated With IC 1795 (W3)

Observations of H166α recombination line emission from 13 positions within the IC 1795, 1805 and 1848 H II region complex are presented. A mean electron temperature of $$6900_{-1400}^{+2700}\,\text{K}$$ is obtained for the extended low-brightness parts of the region. It is suggested that similar regions could give rise to the ‘ diffuse ’ recombination line emission from the galactic ridge.