Isotopic ratios at z=0.68 from molecular absorption lines toward B 0218+357
Artikel i vetenskaplig tidskrift, 2016

Isotopic ratios of heavy elements are a key signature of the nucleosynthesis processes in stellar interiors. The contribution of successive generations of stars to the metal enrichment of the Universe is imprinted on the evolution of isotopic ratios over time. We investigate the isotopic ratios of carbon, nitrogen, oxygen, and sulfur through millimeter molecular absorption lines arising in the z = 0.68 absorber toward the blazar B 0218+357. We find that these ratios differ from those observed in the Galactic interstellar medium, but are remarkably close to those in the only other source at intermediate redshift for which isotopic ratios have been measured to date, the z = 0.89 absorber in front of PKS 1830-211. The isotopic ratios in these two absorbers should reflect enrichment mostly from massive stars, and they are indeed close to the values observed toward local starburst galaxies. Our measurements set constraints on nucleosynthesis and chemical evolution models.

ISM: molecules

galaxies: ISM

galaxies: abundances

quasars: absorption lines

radio lines: galaxies

quasars: individual: B 0218+357


Sofia Wallström

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

Sebastien Muller

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

M. Guelin

IRAM Institut de RadioAstronomie Millimetrique

École Normale Supérieure

Astronomy and Astrophysics

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

Vol. 595 Art no A96- A96


Astronomi, astrofysik och kosmologi