Forbidden absorption bands of O2 in the argon continuum region

Abstract

The absorption spectrum of O₂ has been photographed in the argon continuum region with a 3-m vacuum spectrograph at a dispersion of 1.42 Å/mm. Based on the known rotational constants of the ground state, the rotational constants of the upper states have been determined for Tanaka progession (I), β–X³Σ_g⁻, progression (II), α¹Σ_u⁺–X³Σ⁻, and those of a new band at 1144.6 Å. In a brief discussion of the upper electronic states, it is suggested that both the β state and the upper states of the 1144.6 Å band are ³Σ_u⁺ states and their electron configurations are (π_g2p)(3pπ) and (π_g2p)(4pπ), respectively, and also the α state is (π_g2p)(3pπ)¹Σ_u⁺.