Absorption Coefficients of C6H6 and H2 in the Vacuum Ultraviolet

Critical review of ultraviolet photoabsorption cross sections for molecules of astrophysical and aeronomic interest

“…The bands observed between 740 A and 840 A are known to predissociate [Comes and Wellem, 1968] and preionize [Cook and Metzger, 19646;Chupka and Berkowitz, 1968] into the underlying continua. However, theoretical calculations indicate that the rotational lines will be quite narrow, with halfwidths of the order of 1 cm -1 [Nielsen and Berry, 1968] The total absorption cross section of molecular hydrogen has been measured in the wavelength interval 200 A to 840 A by Cook and Metzger [19646] ; Comes and Wellem [1968] ; Wainfan et al [1955] ; Bunch et al [1958] ; and Samson and Cairns [1965]. Of these measurements, those of Cook and Metzger and of Comes and Wellern used a continuum light source.…”

CN radical hydrogenation from solid H2 reactions, an alternative way of HCN formation in the interstellar medium

“…The edge of the absorption band of H 2 overlaps with the 121 nm radiation (Bunch et al 1958) and therefore we have to take into account that an excited state or photodissociation of H 2 could be involved in the previous formation of HCN. To verify that the observed reactivity is exclusively due to the cleavage of cyanogen, we changed the MgF 2 window of our system with a sapphire which cuts off radiation below 147 nm.…”