Chlorine-bearing molecules in molecular absorbers at intermediate redshifts
Artikel i vetenskaplig tidskrift, 2019

We use observations of chlorine-bearing species in molecular absorbers at intermediate redshifts to investigate chemical properties and Cl-35/Cl-37 isotopic ratios in the absorbing sightlines. Chloronium (H2Cl+) is detected along three independent lines of sight in the z = 0.89 and z = 0.68 molecular absorbers located in front of the lensed quasars PKS 1830-211 and B 0218+357, respectively. Hydrogen chloride (HCl) was observed only toward PKS 1830-211, and is found to behave differently from H2Cl+. It is detected in one line of sight with an abundance ratio [H2Cl+]/[HCl] similar to 1, but remains undetected in the other, more diffuse, line of sight, with a ratio [H2Cl+] / [HCl] > 17. The absorption profiles of these two chlorine-bearing species are compared to other species and discussed in terms of the physical properties of the absorbing gas. Our findings are consistent with the picture emerging from chemical models where different species trace gas with different molecular hydrogen fraction. The Cl-35/Cl-37 isotopic ratios are measured in the different lines of sight and are discussed in terms of stellar nucleosynthesis.

radio lines: galaxies

galaxies: ISM

quasars: individual: B 0218+357

quasars: individual: PKS 1830-211

quasars: absorption lines

galaxies: abundances


S. H. J. Wallstrom

KU Leuven

Academia Sinica

Sebastien Muller

Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium

Evelyne Roueff

Université Pierre et Marie Curie (UPMC)

R. Le Gal

Harvard-Smithsonian Center for Astrophysics

John H Black

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

M. Gerin

Université Pierre et Marie Curie (UPMC)

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 629 A128


Astronomi, astrofysik och kosmologi


Teoretisk kemi


Onsala rymdobservatorium



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