===== HCl in Extragalactic Sources =====

S. H. J. Wallström, S. Muller, E. Roueff, R. Le Gal, J. H. Black, and M. Gérin\\
reported on the\\
**[[https://doi.org/10.1051/0004-6361/201935860|Chlorine-bearing Molecules in Molecular Absorbers at Intermediate Redshifts]]**\\
//Astron. Astrophys.// **566**, (2014) Art. No. L6.\\
The 1 – 0 transitions of H<sup>35</sup>Cl and H<sup>37</sup>Cl were observed with ALMA in the //z// ≈ 0.89 foreground galaxy of the lensed quasar PKA 1830−211. The isotopologs were both detected in the molecule rich SW image, where a H<sub>2</sub>Cl<sup>+</sup> to HCl ratio of ~1 was obtained, and unsurprisingly not toward the more atomic NE image, where a H<sub>2</sub>Cl<sup>+</sup> to HCl ratio of > 17 was deduced. 
HCl was also not observed in the //z// ≈ 0.68 foreground galaxy of the lensed quasar B 0218+357.\\
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Contributor(s): H. S. P. Müller; 11, 2025

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