1. Quantum-state–selective electron recombination studies suggest enhanced abundance of primordial HeH+.
- Author
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Novotný, Oldřich, Wilhelm, Patrick, Paul, Daniel, Kálosi, Ábel, Saurabh, Sunny, Becker, Arno, Blaum, Klaus, George, Sebastian, Göck, Jürgen, Grieser, Manfred, Grussie, Florian, von Hahn, Robert, Krantz, Claude, Kreckel, Holger, Meyer, Christian, Mishra, Preeti M., Muell, Damian, Nuesslein, Felix, Orlov, Dmitry A., and Rimmler, Marius
- Subjects
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QUANTUM states , *HELIUM hydrides , *ASTROCHEMISTRY , *ELECTRONS , *METAPHYSICAL cosmology - Abstract
The epoch of first star formation in the early Universe was dominated by simple atomic and molecular species consisting mainly of two elements: hydrogen and helium. Gaining insight into this constitutive era requires a thorough understanding of molecular reactivity under primordial conditions. We used a cryogenic ion storage ring combined with a merged electron beam to measure state-specific rate coefficients of dissociative recombination, a process by which electrons destroy molecular ions. We found a pronounced decrease of the electron recombination rates for the lowest rotational states of the helium hydride ion (HeH+), compared with previous measurements at room temperature. The reduced destruction of cold HeH+ translates into an enhanced abundance of this primordial molecule at redshifts of first star and galaxy formation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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