Non-thermal photons and direct photodissociation of H2, HD and HeH+ in the chemistry of the primordial Universe

Abstract

Non-thermal photons deriving from radiative transitions among the internal ladder of atoms and molecules are an important source of photons in addition to thermal and stellar sources in many astrophysical environments. In the present work the calculation of reaction rates for the direct photodissociation of some molecules relevant in early Universe chemistry is presented; in particular, the calculations include non-thermal photons deriving from the recombination of primordial hydrogen and helium atoms for the cases of H2, HD and HeH+. New effects on the fractional abundances of chemical species are investigated and the fits for the HeH+ photodissociation rates by thermal photons are provided.

6 pages, 4 figures, 1 table; accepted for publication on MNRAS

References in corpus (6)

• Lines in the cosmic microwave background spectrum from the epoch of cosmological helium recombination
• Free-bound emission from cosmological hydrogen recombination
• Effects of primordial chemistry on the cosmic microwave background
• Vibrational level population of H${}_2$ and H${}_2^{+}$ in the early Universe
• Cosmological production of H_2 before the formation of the first galaxies
• Water destruction by X-rays in young stellar objects

Cited by in corpus (1)

• Distortion of the CMB spectrum by the first molecules of the Dark Ages